A STUDY ON THE TAXONOMY OF THE CATFISHES OF KERALA AT THE

SPECIES LEVEL IN A PRELIMINARY FRAME WORK

RESEARCH REPORT

SUBMITTED TO

INDIAN ACADEMY OF SCIENCES, BANGALORE

BY

ANEESHA DEVASSY

SUPERVISED BY

DR. T. C. NARENDRAN

PROFESSOR AND HEAD OF THE DEPARTMENT (RETIRED),

C/O DEPARTMENT OF ZOOLOGY,

UNIVERSITY OF CALICUT

2010

Name of SRF : Aneesha Devassy

Registration Number : LFS 704

Institution where working : Research Scholar, School of Biosciences,

Mahatma Gandhi University, Kottayam

Date of joining the project : April 4, 2010

Date of Completion of the project : June 4, 2010

Name of the Guide : DR. T. C. NARENDRAN, Professor and Head

of the Department (Retired), c/o Department of

Zoology, University of Calicut

Project Title : A study on the taxonomy of the catfishes of

Kerala in a preliminary framework.

Signature of the guide :

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UNIVERSITY OF CALICUT

Dr. T. C. Narendran, Ph.D.,FASc.Professor & Head (Retd.)

C/o Systematic Entomology Laboratory

DEPARTMENT OF ZOOLOGYUNIVERSITY OF CALICUT

Kerala – 673 635, IndiaOffice: 0494 2401144*419

Res.: 0494 2400302E-mail : drtcnarendran@yahoo.com

CERTIFICATE

This is to certify that this research report “A study on the taxonomy of the catfishes of

Kerala at the species level in a preliminary frame work” is an authentic record of work done

by Miss. Aneesha Devassy, Summer Research Fellow, Indian Academy of Sciences, Bangalore,

in the Systematic Entomology Laboratory, Department of Zoology, University of Calicut under

my guidance and supervision.

Dr. T. C. Narendran

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DECLARATION

I hereby declare that this dissertation entitled “A STUDY ON THE

TAXONOMY OF THE CATFISHES OF KERALA AT THE SPECIES LEVEL IN

A PRELIMINARY FRAME WORK” submitted to Indian Academy of Sciences,

Bangalore, has been originally carried out under the guidance and supervision of

Professor Dr. T. C. Narendran at the Systemic Entomology Laboratory, Department of

Zoology, University of Calicut, Calicut.

Aneesha Devassy

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ACKNOWLEDGEMENT

In the submission of this project, I express my

gratitude to:

  Above all else, I acknowledge gratefully the

grace of the Almighty, experienced during each step

of this project and in its successful completion. 

  Sincere gratitude to Indian Academy of Sciences,

Bangalore, for selecting me for the Summer

Research Fellowship that provided me the

opportunity to conduct this study.

  This project was carried out under the able and

inspirational guidance of Dr. T. C. Narendran,

Professor and Head of Department (Retired) c/o

Department of Zoology, University of Calicut. I

remain deeply indebted to him, for his constant

encouragement, suggestions, and optimism that

inspired me throughout this project.

My sincere thanks to Dr. N. Ramani, Head of the

Department of Zoology, University of Calicut, for

providing me the necessary facilities in the

Department. I also thank Professor Dr. M. S. Latha,

Director, School of Biosciences, Mahatma Gandhi

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University, Kottayam for permitting me to undertake

this fellowship programme.

My heartfelt gratitude to my research guide Dr.

Linu Mathew, for the invaluable support and

guidance throughout this work.

  I am extremely grateful to Dr. K. G.

Padmakumar, Professor and Associate Director

(Aquaculture), Regional Agricultural Research

Station, RARS, Kumarakom, for the invaluable

guidance and help without which this project would

not have reached completion.

  I would also like to gratefully acknowledge the

assistance rendered throughout this work by

Mr. Rakesh C. G., SRF, RARS, Kumarakom.

I convey my sincere thanks to Dr. Sr. Karmaly for

all help and encouragement.

I thank Mr. Antony Chirakkal, Mr. Akhil Antony,

Mr. Arun Antony and all other persons for helping me

to collect the fish specimens, live samples. I would

also like to thank Mr. Shaju for the photographic work

involved. I wish to express my sincere thanks to Ms.

Sreedevi S. for her help and support.

I express my affection and deep sense of

gratitude to all my researcher friends Ms. Lakshmi

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Devi Menon, Ms. Veena P., Mr. Santhosh S. Nair, Mr.

Abhilash Peter, and Ms. Sheeba M. for their whole

hearted and sincere cooperation in my work.

  Last but not least I express my gratitude to my

family for their constant encouragement and prayer

without which I would not have been able to pursue

the course of my study.

Aneesha Devassy.

“For it is he who gave me unerring

knowledge of what exist, to know the

structure of the world and the activity of

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elements; the beginning and end and

middle of times, the alterations of the

solstices and the changes of the seasons,

the cycles of the year and the

constellations of the stars, the natures of

animals and the tempers of the wild

animal, the powers of the spirits and the

thoughts of the human beings, the

varieties of plants and the virtues of roots;

I learned both what is secret and what is

manifest, foe wisdom, the sashioner of all

things, taught me.”

Wisdom of Solomon 7: 17-22

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Glossary

Adipose fin : A small and fleshy fin, without rays, placed behind the

dorsal fin on the back of some fishes.

Air bladder : A gas filled sac located in the body cavity below the

vertebrae

Anal fin : The unpaired fin on the midline of underside of body, just

behind the vent

Antrorse : Pointing forward

Anus or vent : The opening at the posterior end of the digestive tract.

Barbel : A slender, tactile, whisker like projection extending from

the head of some fishes; they function primarily as a

sensory organ for locating food.

Base : The part where a fin joins body, as in length of dorsal or

anal fin base

Branchial : Pertaining to gills.

Branchiostegal : Slender bones which support the gill membranes.

Caudal fin : The tail fin

Cleithrum : One of the bones of the pectoral girdle, on which the

pectoral fin is hinged.

Cloaca : Terminal part of gut into which the kidneys and

reproductive ducts open; in such cases there is only a single

posterior opening to the body, the cloacal aperture, instead

of separate anus and urogenital opening.

Dorsal fin : The unpaired fin/s on the midline of back.

Gill arches : The bony supports to which the gills are attached.

Gonopodium : Modified anal finrays, elongated and thickened, and

functioning as an organ of transference of spermatophores

to the body of the female.

Isthmus : The fleshy interspace below the head and between the gill

openings.

Lateral line : Line formed along each side of body by a series of pores or

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minute tubes on scales or skin; most species of fish have a

lateral line.

Nape : The upper neck region.

Nostril : On the snout of fishes the opening of the olfactory organ or

organ of smell; in fishes there are usually a pair of nostrils

on each side of head.

Nictitating membrane : Transparent fold of skin forming a third eyelid; when open

lies at inner (anterior) corner of eye or below lower eyelid.

Occipital process : A median bone on the upper surface of the back of the

head; pertaining to the occiput.

Operculum : The gill cover

Osseous : Bony

Pectoral fins : The paired fins attached to the shoulder girdle.

Pelvic fins : The paired fins placed behind or below the pectoral fins;

often also referred to as ‘ventral fins’.

Preopercle : The anterior cheek bones.

Taxonomy : The science of classification at all levels starting with the

individual and arranging or grouping according to

relationships.

Operculum : The gill cover

Ventral fins : Pelvic fins.

Vestigial : Small and imperfectly developed; rudimentary.

Vomer : Bone in mid-palate, often bearing teeth.

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CONTENTS

Introduction - 11

Review of Literature - 15

Aims and Objectives - 17

Materials and Methods - 18

Results - 19

Order Siluriformes - 22

1. Family Bagridae - 27

1. Family Siluridae - 45

1. Family Schilbeidae - 54

1. Family Sisoridae - 61

1. Family Clariidae - 70

2. Family Heteropneustidae - 74

1. Family Ariidae - 78

1. Family Plotosidae - 80

Discussion - 85

Summary - 89

Conclusion - 90

Bibliography - 91

Plates - 95

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INTRODUCTION

Systematics is the science of the diversity of the organisms. It is the scientific

study of the kinds and diversity of organisms and of any and all relationships among

them (Simpson, 1961). Systematics is one of the most essential branches of biology. The

multitude of species occurring in nature are studied, classified and named so that they can

be identified in future.

Each species should have a name unique to itself. Once a name has been given to

a species, it becomes a label by which information concerning that organism is

communicated, stored and retrieved (Narendran, 2000). Systematics attempts to

systematize nature and provides a working conceptual framework enabling us to make

further studies such as biodiversity of fauna and flora, biology of various species

conservation, evolution, distribution, genetics, biotechnology and various other aspects.

Hence studies in systematics is the prime requisite before undertaking any further studies

on the group concerned.

Catfishes are a group of rayfinned fish. They are named so for their prominent

barbels, that resembles a cat’s whiskers. Catfishes range in size and behavior from the

heaviest, the Mekong giant catfish from Southeast Asia and the longest, the Wells catfish

of Eurasia, to detritivores (species that eat dead material on the bottom) and even to a tiny

parasitic species commonly called the ‘Candiru’, Vandellia cirrhosa.

Most catfishes are bottom feeders. In general, they are negatively buoyant, which

means that they will usually sink rather than float due to a reduced gas bladder and a

heavy bony head (Bruton, 1996). They have a variety of body shapes, though most have a

cylindrical body with a flattened ventrum to allow for benthic feeding.

DIAGNOSTIC FEATURES OF CAT FISHES

A great variation exists in the external morphology of catfishes and it is difficult

to give a standard definition of their external appearance. In general the body is naked

although in some families (eg. Callichthyidae; Loricariidae) it is covered with bony

plates.

Head: A flattened head allows for digging through the substrate as well as

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perhaps serving as a hydrofoil. The mouth is in general non-protractile. Most have a

mouth that can expand to a large size and contains no incisiform teeth. Catfish generally

feed through suction or gulping rather than biting and cutting prey (Bruton, 1996).

However some families notably Loricariidae and Astrolepidae, have a sucker mouth that

allows them to fasten themselves to objects in fast moving water. Catfishes also have a

maxilla reduced to a support for barbels; this means that they are unable to protrude their

mouths as other fish such as carp (Bruton, 1996). The eyes are usually small.

Barbels: Catfishes may have up to 4 pairs of barbels: one nasal pair, one or two

maxillary pairs (on each side of mouth), and two pairs of mandibular or mental pairs. In

many families one or more pairs may be missing. The barbels are provided with

numerous taste buds and are used in detecting food. Because their barbels are more

important in detecting food, the eyes on catfishes are generally small.

Bony plates: Catfishes have no scales, their body is often naked. In some species,

the mucus-covered skin is covered skin is used in cutaneous respiration, where the fish

breathes through its skin (Bruton, 1996).

In some catfishes, the skin is covered in bony plates called scutes; some form of

body armor appears in various ways within the order. In Loricariids and in the Asian

genus Sisor, the armor is primarily made up of one or more rows of free dermal plates.

Similar plates are found in large specimens of Lithodoras. These plates may be supported

by vertebral processes, as in Scoloplacids and in Sisor, but the processes never fuse to

plates or form any external armor. By contrast, in the subfamily Doumienaee (family

Amphiliidae) and in Hoplomyzontines (Aspredinidae), the armor is formed solely by

expanded vertebral processes that form plates. Finally the lateral armor of Doradids, Sisor

and Hoplomyzontines consists of hypertrophied lateral line ossicles with dorsal and

ventral lamina.

Fins: The dorsal and pectoral fins are often provided with a leading spine or a

leading soft ray. An adipose fin is often present and in some families it has a spine. The

pelvic fin is medially placed and has an abdominal position. Important variations are also

noted in size, ranging from a few millimeters (eg. Some Scoloplacidae) and a few

centimeters (eg. Helogenidae) upto several meters (eg. Ictaluridae and some

Pimelodidae).

Weberian apparatus: Like other Ostariophysans, the catfishes are characterized

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by the presence of a Weberian apparatus. Their well developed Weberian apparatus and

reduced gas bladder allow for improved hearing as well as sound production (Bruton,

2006).

Order Siluriformes is an unusually well defined order, comprising approximately

30 families (400 genera) and about 2000 species found in its entire range (Jayaram K. C.

2009).

The objective of the present investigation is to undertake studies on the classical

taxonomy of the catfishes of Kerala at species level in a preliminary frame work. Such a

study can give fundamental information for undertaking further detailed study of these

interesting fishes at the molecular level. This faunal diversity will help the researchers in

accessing the name of the species and its distribution.

DISTRIBUTION OF CATFISHES

Catfishes have a wide geographical distribution and are found in South-East Asia,

Eurasia, Central and South America, Africa, Japan and Ausralia. Except for two families

(Ariidae and Plotosidae) with essentially marine species, catfishes are in general primary

freshwater fishes.

HABITAT OF CATFISHES

They are found in freshwater environments of all kinds, though most inhabit

shallow, running water (Bruton, 1996). Representatives of at least 8 families are

hypogean (live underground) with three families that are also troglobitic (Inhabiting

caves) (Langecker, 1993, Hendrickson, 2001). Numerous species from the families

Ariidae and Plotosidae and a few species from Aspredinidae and Bagridae are found in

sea water (Monks, 2006, Schafer, 2005).

IMPORTANCE OF CATFISHES

Catfishes are of considerable commercial importance. Many of the larger species

are farmed or fished for food. Many of the species, particularly the genus Corydoras, are

important in the aquarium hobby.

Catfishes are high in Vitamin D (Vitamin D and healthy bones). Farm raised

catfishes contain low levels of omega-3 fattyacids and a much higher proportion of

omega-6 fatty acids.

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Catfishes rose in inland tanks or channels are considered safe for the environment,

since their waste and disease should be contained and not spread to the wild (Rogers

paul). In Asia many catfish species are important as food. Several ‘Walking Catfish’

(Clariidae) and shark catfish (Pangasidae) species are heavily cultured in Africa and Asia.

There is a large and growing ornamental fish trade, with hundreds of species of

catfishes, such as Corydoras and Plecos being a popular component of many aquaria.

Other catfishes commonly found in aquarium trade are Banjo catfish, Talking catfish and

long whiskered catfish.

ECONOMIC IMPORTANCE

Catfishes have been widely caught and farmed for food for hundreds of years in

Asia, Africa, Europe and North America. Judgments as to the quality and flavor vary,

with some food critics considering catfishes as being excellent food, others dismiss them

as watery and lacking in flavor (Jenny Baker, 1988).

It is easy to farm catfishes in warm climates, leading to inexpensive and safe food

at local grocers.

Catfishes are one of the economically important groups of fresh and brackish

water fishes in the world; in many countries they form a significant part of inland

fisheries; several species have been introduced in fish culture; numerous species are of

interest to the aquarium industry where they represent a substantial portion of the world

trade (Teugels, 1995).

HISTORY OF THE PRESENT STUDY

A proper taxonomy will help to get rid of the taxonomic and nomenclatural chaos

and thereby to facilitate studies of all kinds. An improvement of scientific knowledge is

greatly needed in the taxonomy of catfishes. In almost all regions the identification of

catfishes is very difficult. This poor knowledge is reflected in frequent incorrect or

inadequate identification of the relevant genus and species which results in unreliable or

confusing records in the literature. Only thorough taxonomic research work can improve

the situation. Through this project work, an attempt is made to study the catfishes of

Kerala which are very important food fish economically important to Kerala.

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REVIEW OF LITERATURE

Order Siluriformes is an unusually well defined order, comprising approximately

30 families (400 genera) and about 2000 species found in its entire range (Jayaram K. C.

2009). Many scientists have contributed to the knowledge of the order siluriformes.

A century ago, contributions to the phylogenetic study of the catfishes were

scarce, and dealing only with a few families and with a limited number of taxa within the

families. Teugels reported in 1995 that only few data on catfish phylogeny were known at

that time. Teugels recognized 33 families with 416 genera and 2584 species with a

comment that these numbers were continuously changing.

The catfishes are a monophyletic group. This is supported by molecular evidence

(Sullivan et. al., 2006). Catfishes belong to a super order called the Ostariophysi, which

also includes the Cypriniformes, Characiformes, Gonorynchiformes and Gymnotiformes,

a super order characterized by the Weberian apparatus. Some place Gymnotiformes as a

suborder of Siluriformes, however this is not as widely accepted. Currently, the

Siluriformes are said to be the sister group to the Gymnotiformes; though this has been

debated due to more recent molecular evidence. As of 2007 there are about 36 existing

catfish families, and about 3,023 existing species have been described (Ferraris, 2007).

This makes the catfish order the second or third most diverse vertebrate order; in fact one

out of every 20 vertebrate species is a catfish.

The taxonomy of catfishes is quickly changing. In a 2007 and 2008 paper,

Horabagrus, Phreatobius and Conorhynchos were not classified under any current

catfish families. There is disagreement on the family status of certain groups; for

example, Nelson 2006 lists Auchenoglaniidae and Heteropneustidae as separate families,

while the All Catfish Species Inventory includes them under other families. Also,

FishBase and the Integrated Taxonomic Information System lists Parakysidae as separate

family, while this group is included under Akysidae by both Nelson (2006) and ACSI

(Froese et. al. 2007). Many sources do not list the recently revised family Anchariidae

(Ng 2005). The family Horabagridae including Horabagrus, Pseudotropius and

Platytropius, is also not shown by some authors but presented by others as a true group

(Sullivan, 2006). Thus the actual numbers of families differs between authors. The

species count is in constant flux due to taxonomic work as well as description of new

species.

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The rate of description of new catfishes is at an all time high. Between 2003 and

2005, over100 species have been named, a rate of three times faster than that of the past

century (Ferraris, 2005).

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AIMS AND OBJECTIVES

1. To briefly review the contributions made by scientists all over the world on the

systematics of the order Siluriformes with special reference to contribution on the

catfishes of Kerala.

1. To get an idea of the collection methods of catfishes.

1. To learn to distinguish Clariids from other Siluriformes

1. To learn to identify the various family of the order Siluriformes and various

genera of the families.

1. To get a preliminary training in methods of species description i.e. parameter to

be taken into consideration, drawings, distinguishing between like species etc.

1. To get a training in preparation of dichotomous keys.

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MATERIALS AND METHODS

The present work was to review the taxonomy of the catfishes of Kerala at the

species level in a preliminary framework. Fish samples were collected as live samples

freshly caught from the rivers and as dead samples collected from the available markets.

Live fish sampling was performed in 100 m reach of all study streams. As the

work was carried out in the peak summer season, April and May, 2010 and due to lack of

time the samples isolated were less. Live samples were isolated from Ernakulam and

Kottayam districts from River Periyar and Vembanadu Lake. In each stream the

sampling was made in different habitats such as pools, riffles and runs using fishing nets

such as drag nets, gill nets and scoop nets. After collection, the fishes were kept alive in

plastic containers and transported to the laboratory for further analysis. Species

identification and confirmation were carried out using standard fish taxonomy textbooks

(Talwar and Jhingran 1991; Jayaram 1999). After identification, the fishes were kept in

the aquarium.

The dead samples obtained from the markets were also carried to the laboratory

for further analysis. After identification using standard fish taxonomy textbooks, the

fishes were dropped directly into a solution of dilute formalin 9 to 10 %. This solution is

made by diluting one part of commercial formalin (37% to 41%) with nine or ten parts of

water. A bucket was kept with measured quantity of water and formalin was added.

When the solution was ready the fish was dropped into the bucket and the bucket was

closed with a lid. In the formalin the fin ad rays were fully expanded and this assisted in

identification. The measurements were taken with a stainless steel ruler with

measurements to millimeter.

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RESULTS

The present review work was based on standard fish taxonomy textbooks Talwar

and Jhingran 1991, Jayaram 1999 and Shaji and Easa 2001. From this study it was found

that the catfishes so far reported from Kerala belong to 8 families of the order

Siluriformes. The orders are Plotosidae, Siluridae, Clariidae, Heteropneustidae, Ariidae,

Sisridae, Bagridae and Schilbeidae. A new key is prepared in this work for the families of

catfishes found in Kerala. The various families and genera and species reported from

Kerala are listed below followed by a systematic account. From the study it was found

that Kerala catfishes belong to 8 families, 15 genera and 31 species.

The family Bagridae includes 3 genera and 11 species.

The family Siluridae includes 3 genera and 4 species.

The family Schilbeidae includes 3 genera and 3 species.

The family Sisoridae includes 1 genus with 5 species.

The family Claridae includes 2 genera and 3 species.

Family Heteropneustidae includes 1 genus and 2 species.

Family Ariidae includes 1 genus and 1 species.

Family Plotosidae includes 1 genus and 2 species.

1. Family Bagridae

1. Genus Batasio Blyth, 1860

1. Batasio travancoria Hora & Law

2. Genus Horabagrus Jayaram, 1955

1. Horabagrus brachysoma (Gunther)

2. Horabagrus nigricollaris Pethiyagoda & Kottelat 1994

3. Genus Mystus Scopoli, 1777

1. Mystus armatus (Day)

2. Mystus keletius (Valenciennes)

3. Mystus malabaricus (Jerdon)

4. Mystus montanus (Jerdon)

5. Mystus oculatus (Valenciennes)

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6. Mystus punctatus (Jerdon)

7. Mystus cavasius (Hamilton-Buchanan)

8. Mystus vittatus (Bloch)

2. Family Siluridae

1. Genus Ompok Lacepede, 1803

1. Ompok bimaculatus (Bloch, 1794)

2. Ompok malabaricus (Valenciennes, 1840)

2.Genus Wallago Bleeker, 1851

1.Wallago attu (Bloch & Schneider, 1801)

3.Genus Silurus Linnaeus, 1758

1.Silurus wynaadensis Day, 1873

3.Family Schielbeidae

1.Genus Pseudeutropius Bleeker 1862

1.Pseudeutropius mitchelli Gunther, 1864

2.Genus Proeutropiichthys Hora 1937

1. Proeutropiichthys takree takree (Sykes 1839)

3. Genus Silonia Swainson, 1838

1. Silonia childreni (Sykes)

4. Family Sisoridae

1. Genus Glyptothorax Blyth

1. Glyptothorax anamaliensis Silas, 1951

2. Glyptothorax annandalei Hora, 1923

3. Glyptothorax housei Herre, 1942

4. Glyptothorax lonah (Sykes, 1839)

5. Glyptothorax madraspatanum (Day, 1873)

5. Family Clariidae

1. Genus Clarias Scopoli

1. Clarias dussumieri dussumieri Valenciennes 1840

2. Clarias dussumieri dayi, 1936

2. Genus Horaglanis Menon

1. Horaglanis krishnai Menon, 1950

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6. Family Heteropneustidae

1. Genus Heteropneustes Muller

1. Heteropneustis fossilis (Bloch, 1794)

2. Heteropneustes microps (Gunther, 1864)

7. Family Ariidae

1. Genus Arius Valenciennes

1. Arius arius (Hamilton-Buchanan, 1822)

8. Family Plotosidae

1. Genus Plotosus Lacepede

1. Plotosus canius (Hamilton-Buchanan, 1822)

2. Plotosus lineatus (Thunberg, 1787)

SYSTEMATIC ACCOUNT

Superclass GNATHOSTOMATA

Class ACTINOPTERYGII

Subclass NEOPTERYGII

Division TELEOSTEI

Division TELEOSTEI

Diagnosis: Endoskeleton bony, sometimes cartilaginous. Membrane bones of head well

developed; skull hyostylic; sometimes amphistylic; skull with sutures; endocranium

ossified. Optic nerves forming or not forming a solid chiasma. Maxilla well toothed,

simple. Palato–quadrate not fused with endocranium. Soft fin rays usually segmented

with pterygials; mostly with two paired fins (pectoral and pelvic), one or more medium

dorsal fin, and an anal fin ventrally and a caudal fin posteriorly; fins with spines and/or

soft rays; four pairs of gill arches; fifth pair modified into tooth-bearing lower

pharyngeal. Biting edge of upper jaw usually formed by dermal bones, the premaxillae

and maxillae; latter mobile. No supramaxilla. Gills with outer edges free; their bases

attached to bony arches; a single lateral gill opening on either side of pharynx covered by

operculum or a single ventral gill opening in pharynx. Interoperculum present. Nostrils

relatively high up in head. Heart divided into auricle, ventricle and arterial bulb; arterial

bulb either muscular with numerous valves or thin with a pair of opposite valves.

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Branchial septa reduced. Branchial lamellae with double row of branchial rays. No

intestinal valve. No nictitating membrane. Air-bladder or lung present. Skin with cycloid

or ctenoid scales. No cloaca except in Nerophis aequoreus (L.) (Syngnathidae). No

pterygopodia but some with gonopodium. Ova small; mostly oviparous; a few viviparous.

Lower Devonian to recent.

Catfishes belong to the order Siluriformes in this division. So a key is provided only up to

the order Siluriformes.

KEY TO ORDERS

1. Body cylindrical, much elongated and eel-

shaped.............................................................2

Body rounded not eel-shaped.............................................................................................3

2. Gill openings confluent, a single slit on ventral surface. Dorsal and anal fins

vestigial or

absent.......................................................................................................Synbranchiformes

= Gill openings free, narrow, on arches of head.Dorsal and anal fins, long, continuous

with caudal fins……….................................................................................Anguilliformes

3. Body short, rounded. Bones of upper and lower in the form of a beak having a

cutting edge and covered with a layer of ivory like

substance......................................................

…………………………………………………………..... ……………Tetraodontiformes

=Body fusiform, Bones of upper jaw normal without any modifications above..............

………………………………………………………………………………Siluriformes

Order SILURIFORMES

Skin naked or with bony scutes or plates, never with true scales. Mouth

not protractile, superiorly bordered by premaxillaries and dentaries, which are generally

toothed as are the pterygoids, palatines and vomer; maxillaries much reduced, toothless,

serving as bases of maxillary barbels. Nearly always one to four pairs of barbels. Adipose

fin generally present. Symplectic, subopercular and intermuscular bones, parietals, first

and second pharyngobranchials, epipleural and epineural bones absent. Pharyngeal bones

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with small conical or villiform teeth. Branchiostegal rays 4 to 17. No pseudobranchiae.

Mesopterygoid reduced, preopercle and interopercle relatively small. Anterior vertebrae,

second, third, fourth coossified to form “complex vertebra”; additional posterior vertebral

centra may be frequently fused to or united by exceedingly tight joints with complex

vertebra. Ribs attached to lower surface of long parapophyses. Supracleithrum

complicated; lower part deeply forked for reception of upper limb of cleithrum. First

pectoral, and last dorsal fin rays modified as hard pungent spines or thick rays. Lateral

line may be ramified, with or without short tubular ossicles enclosing the line. Pelvic fin

abdominal in position. Principal caudal fin rays 18 or fewer (most with 17), caudal

skeleton generally have six hypural plates. Air-bladder subdivided, reduced in many

species.

Order Siluriformes is an unusually well defined order, comprising approximately

30 families (400 genera) and about 2000 species found in its entire range. Most are

confined to freshwater but some are marine.

In this short review work, only the families, genera and species reported from

Kerala are dealt with. 8 families, 16 genera and 30 species of catfishes are commonly

found in Kerala. They are discussed below.

KEY TO FAMILIES FOUND IN KERALA

1. Adipose dorsal fin absent

(fig.1)..........................................................................................2

Fig.1

=Adipose dorsal fin present (fig.2) as a smooth short or long low fin (exception

Clupisoma garua (Hamilton –Buchanan), Schilbeidae where it may be absent in

adult.....................................................................................................................................5

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24

Fig.2

2. Dorsal fin with a spine. Pelvic fins with 15or 16 rays. Anal fin long, confluent

with caudal fin (fig.3) [Body eel like].................................................................

PLOTOSIDAE

Fig. 3

=Dorsal fin without any spine. Pelvic fins with 6 rays. Anal fin free................................3

3. Nasal barbels absent (fig.4). No accessory respiratory organs [Barbels two or

three pairs; Head fairly compressed]

……………………………………..........................SILURIDAE

Fig. 4

= Nasal barbels present. Accessory respiratory organs present on gills or in the body

cavity………………………………………………………………………………………4

4. Dorsal fin long, with 23 to 76 rays. Accessory respiratory organs (air-breathing

labrynthic organ in branchial chamber) on gills present.

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25

(fig.5).......................................CLARIIDAE

Fig.5

= Dorsal fin short, with six or seven rays. Accessory respiratory organs as tubular air

sacs present in body cavity (fig.6) [Barbels four pairs; Head greatly depressed; long

air-sac serving as a lung extends posteriorly from gill chamber]…………………………..

………………………………………………………………….HETEROPNEUSTIDAE

Fig. 6

5. Nostrils close together (fig.7), with very little inter space between the

two...................6

Fig. 7

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26

= Nostrils wide apart (fig.8), separated with some inter space, between the two................

……………………………………………………………………………………………..7

Fig. 8

6. No nasal barbels present (fig.9). Barbels two to six. Nostrils separated by a valve

[mainly marine and estuarine]........

……………………………………………………..ARIIDAE

Fig. 9

= A pair of distinct nasal barbels present. Nostrils close together, separated by a barbel.

Barbels eight. [Lateral line always present. Gill membranes united with isthmus

(exception Bagarius Hamilton-Buchanan); mostly small forms occurring in mountain

rapids]…………………………………….......................................................SISORIDAE

7. Anal fin short with less than 20 rays (8 to 16) (Fig.10); (exception Horabagrus

Jayaram,

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from Kerala with 23 to 28 rays) [Nostrils wide apart; teeth on roof of mouth; Dorsal and

pectoral spines strong]………........................................................................ BAGRIDAE

Fig. 10

8. Anal fin with more than 20 rays (40 to 46) (fig.11). [Chin barbells absent; nasal

barbells usually present (except in genus Silonia which has caniniform teeth; Anal fin

with 40 to 46 rays)]…… …………………………………………………………

SCHILBEIDAE

Fig. 11

1. Family BAGRIDAE

Bagrid catfishes

Generally large sized, more or less elongate fishes, with a compressed body. Teeth

on pre-maxillaries, mandible and vomer. Nostrils widely separated, above angle of

mouth, anterior tubular on tip of snout, posterior nearer eye than tip of snout and with

nasal barbel. Barbels six or eight, generally well developed. Gill openings wide,

extending to above base of pectoral fins, membranes free from each other and also from

isthmus. Rayed dorsal fin short, inserted anteriorly above middle of pectoral fins, with six

to eight rays and spine. Adipose dorsal fin smooth; not confluent with either rayed dorsal

or with caudal. Paired fins inserted horizontally. Pectoral fins with a strong spine,

generally serrated. Anal fin short or moderately long, not confluent with caudal. Caudal

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28

fin forked or deeply emarginated. Lateral line present, generally complete.

Air bladder large, free in the abdominal cavity, moderately thick walled.

Lateral ethmoid facet for articulation of palatines more ventral than lateral, usually

visible from underside of skull. Palatines rod like. Endopterygoid absent. Ecto-

metaperygoids present, variously developed. Metapterygoid may not be directly

connected to hyomandibular. Vomer large or small, dentigerous. Autopterotics and

autosphenotics provide ventrally articular facet for hyomandibular, but variable. Post-

temporals present, united to skull by ligament. Mesocoracoid in pectoral girdle present.

Vertebrae 34 to 57

HABITAT: Fresh water; shore and bottom water habitat. (Balogun, 2005)

DISTRIBUTION (world wide): Freshwaters of Africa and Asia: ranging from Africa

through Bangladesh, Cambodia, China, East Indies, Formosa, India, Japan, Korea, Laos,

Malaya, Manchuria, Pakistan, SriLnka, Thailand, Vietnam and West Asia.

In India: Orissa, Madhya Pradesh, Assam, North Bengal, Kerala, Uttar Pradesh, Tamil

Nadu, Karnataka, Maharashtra, West Bengal, Manipur, Western Ghats, Eastern ghats.

Number of genus: 4, Batasio Blyth, Horabagrus Jayaram, Mystus Scopoli, Aurichthys

Wu.

2 subfamilies are present in family Bagridae. Members of one subfamily (Bagrinae) is

only reported from Kerala. It includes 4 genera and 12 species. They are discussed here

with their distribution in different parts of Kerala.

Key to subfamily

1. Pelvic fin with seven or eight

rays..........................................................................RITINAE

Pelvic fins with six rays only..............................................................................BAGRINAE

Key to genera of subfamily bagrinae found in kerala

1. Eyes inferior, visible from below ventral surface

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29

(fig.12)................................................. 2

Fig. 12

= Eyes superior, not visible from below ventral surface (fig.13)................................. 3

Fig. 13

2. Anal fin base long with 23 to 28 soft rays (fig14). A dark shoulder spot

present…….......................................................................................................Horabagrus

Fig. 14

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30

= Anal fin short with 15 or 16 rays (fig.15);

Fig. 15

An interneural shield in between basal bone of dorsal fin and occipital bone present

(fig.16)...................................................................................................................... Aorichthys

Fig. 16

3. Barbels generally short including the maxillary pair and not extending beyond

head; ventral surface of head with sensory pores [Eyes moderate size, with free orbital

rim, not visible from underside of head; pectoral fins shorter, do not extend to pelvic fins]

……………………………………….............................................................. Batasio

= Barbels long, maxillary pair longer than head; ventral surface of head without any

pores [Interneural shield absent]..............................................................................Mystus

1. Genus BATASIO Blyth

Batasio Blyth, 1861, J. Asiat. Soc. Beng., 29: 149. (Type – species, Batasio buchanani

Blyth = Pimelodus batasio Hamilton – Buchanan); Hora and Law 1941, Rec.

Indian Mus., 43(1): 28-42 (Revision)

Macronoides Hora, 1921, Rec. Indian Mus., 22(3): 179 (type –species: Batasio affinis

Blyth = Pimelodus tengana Hamilton-Buchanan).

Diagnosis: Body short but elongated, high and compressed. Abdomen rounded. Head

small, compressed, conical with pores ventrally and on side; Snout rounded or slightly

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pointed; Mouth inferior, crescentic, horizontal, not wide with fringed lip; Eyes moderate,

dorsolateral, in middle part of head, not visible from below ventral surface; lips fleshy,

fimbriated; jaws subequal or slightly overhanging; teeth uniformly villiform in broad

continuous bands on jaws and palate; band on lower jaw continuous. Four pairs of

barbels; one on each of maxillary, nasal and two of mandibular, all generally not

extending beyond head posteriorly. Gill membranes notched anteriorly, free from

isthmus.

Rayed dorsal fin short, inserted above three fourth of pectoral fins anteriorly, with

seven or eight rays and a weak spine. Adipose dorsal fin low, of varying length. Pectoral

fins with five to nine soft rays, and a strong spine serrated along inner edge with antrorse

teeth. Pelvic fin with 6 rays. Anal fin short, with 12 to 15 rays. Caudal fin deeply forked

or deeply emarginated. Lateral line complete, with some sensory pores anteriorly.

Number of species: In India – 3 species (Batasio batasio, Batasio tengana and Batasio

travancoria

In Kerala – 1 species (Batasio travancoria)

Habitat: Fresh Water Rivers

Distribution: This genus is endemic to South Asia. India: Assam, North Bengal, And

Kerala, Bangladesh: Northern parts, Thailand and Malaysia.

Remarks: Talwar and Jhingran (1991, p.574) have merged this genus with Rama Bleeker

as a synonym of Batasio in his work (1981, p. 191).

Species found in Kerala

Batasio travancoria Hora & Law

(Plate I - Fig.1)

Batasio travancoria Hora and Law, 1941, Rec, Indian Mus., 43(1):40, pl.2, figs 7, 8 &9

(Type-locality: Perunthenaruvi, tributary of Pampa river at Edakadathy, Kerala);

Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 220, pl. 5, figs 1, 2 &3.

Description: Body elongate and compressed. Head globular, conical and rounded

anteriorly; occipital process long, separated by a considerable distance from basal bone of

dorsal fin; median longitudinal groove on head long and narrow, extending to base of

occipital process. Mouth small and inferior; barbels four pairs. Five large oval pores

behind lower lip, and two rows (of six rows each) of pores between angle of mouth and

gill cover; several pores between nostrils, below eyes and along free border of gill covers.

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Dorsal spine weak; adipose fin with a prominent ridge. Caudal fin deeply forked.

Habitat: Freshwater rivers; Demersal. Tropical climate

Distribution: This endemic species is known from Perumthenaruvi in Trivandrum (Hora

&Law, 1941), Cheenkannippuzha, Chalakudy puzha (Shaji et al. 1995; Shaji and Easa,

1999), Neyyar (Easa et al. 2000), Achenkovilar, Chaliyar, also from Pamba, Kallada,

Chittar rivers in the Anaimalai hill range, Kerala.

Local name: Travancore batasio, Malabar batasio.

Remarks: Occurs in hill streams and rivers at base of hills (Menon, A.G.K., 1999). B.

travancoria has only once been imported to the U.S. In captivity, the experience of one

aquarist is that specimens of B. travancoria show little interest in all foods offered and

slowly lose weight over a span of a few months and perish.

2. Genus HORABAGRUS Jayaram

Horabagrus Jayaram, 1955, Bull. Nat. Inst. Sci. India, No. 7, p.261 (type species

Psedobagrus brachysoma Gunther); Jayaram, 1966, Int. Revue ges. Hydrobiol.,

51(3): 447-448 (Review)

Pseudobagrus (nec Bleeker) Misra, 1976, Fauna of India, Pisces (2nd ed.), 3:108.

Diagnosis: Body moderately elongated, compressed at the tail region. Abdomen rounded.

Head large, anteriorly depressed. Snout obtusely rounded. Mouth subterminal, transverse,

wide. Eyes large, inferior, along angle of mouth, visible when viewed from below ventral

surface. Jaws subequal. Lips thin, plain. Teeth uniformly villiform on jaws and palate. 4

pairs of barbels, one on each of maxillary, nasal, and two of mandibular. Gill membranes

free from each other and also from isthmus.

Rayed dorsal fin inserted above half of pectoral fin, with 5-7 rays and a spine.

Adipose dorsal fin low, short of varying length and depth; inserted far behind the dorsal

origin. Pectoral fins with 8 or 9 rays and a spine serrated along inner edge with antrorse

teeth. Pelvic fins with 6 rays. Anal fin long, with 23 to 29 rays. Caudal fin forked or

deeply emarginated. Lateral line complete, simple.

Number of species: In India: 2

In kerala: 2

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Habitat: Fresh water rivers.

Distribution: In India: Kerala. The northern limit is Kanara and the Southern limit is

Neyyattinkara near Trivandrum.

Remarks: Economically very important as food and aquarium fishes.

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Key to Kerala species of Horabagrus

1. A large saddle shaped black band extending from the humeral region of each side

over the nape, boardered in pale yellow.…………….…………………………........….H.

nigricollaris

= No such saddle shaped band. A large round black spot on shoulder with a light yellow

ring……………………………………………….......…………....……………H. brachysoma

Species found in Kerala

1. Horabagrus brachysoma (Gunther)

(Fig.17, Plate I - Fig.2)

Pseudobagrus brachysoma, Gunther, 1864, Cat. Fishes Br. Mus., 5: 86 (type-locality:

Cochin); Jayaram, 1952, Ann. Mag. Nat. Hist., (12) 5: 982 (Type-locality

revised); Misra, 1976, Fauna of India, Pisces (2nd ed.), 3:109.

Pseudobagrus chryseus Day, 1865, Fishes of Malabar: 185, pl. 13, fig. 2 (type-locality:

Kariyannur river, Kerala).

Macrones chryseus: Day, 1877, Fishes of India: 443, pl.99, fig. 3; Day, 1889, Fauna Br.

India, Fishes, 1: 148, fig. 63.

Horabagrus brachysoma: Jayaram, 1966, Int. Revue ges. Hydrobiol., 51 (3): 447, fig.5.

Diagnosis: Occipital process extends to the base of the dorsal fin. Dark yellowish in

colour with dark black blotch at the humeral region characterized by a light yellow ring.

Habitat: Fresh water; brackish. Benthic, primarily occupying low land areas of rivers and

backwaters with mud and sand substrate. Also seen in deep pools in hill streams.

Distribution: This endemic is abundant in the Vemband Lake, Sasthamkotta Lake,

Chalakudypuzha, Kannur, Trichur, Karivannorpuzha and Periyar.

Local name: Gunther’s catfish, Manjaletta (Mal.), Manjakkoori (Mal.)

Remarks: It is a very common catfish in the Kerala backwaters ans sold in live

condition. It attains a size of 45 cm total length and forms and important element of the

local fishery during the rainy season (October to February). It is caught by traps and long

lines.

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Fig. 17

2. Horabagrus nigricollaris Pethiyagoda & Kottelat 1994

(Plate I - Fig.3)

Horabagrus brachysoma, 1994, Pethiyagoda and Kottelat by original description.

Diagnosis: Maxillary barbels extend beyond the pectoral fin; median longitudinal groove

on the head not extends to the base of the occipital process. Body grey brown. A saddle

shaped black band edged with white extend from the humeral region to nape. Caudal fin

light yellow.

Habitat: Fresh water rivers.It inhabits hill streams at upper reaches of rivers.

Distribution: Chalakudy River, 24 km upstream of Chalakudy town near Vettilappara,

Kerala. So far it is known only from the type locality (Petiyagoda and Kottelat, 1994;

Shaji and Easa, 1999).

Local name: Periyar Catfish

Remarks: This is a recently described species from Chalakudy River at Vettilappara.

This species come very near Horabagrus brachysoma in general appearance but differs

from it in having 1) A saddle shaped band over the nape (such a band is absent in H.

brachysoma); 2) No ocellus at the humeral region (A black ocellus present at the humeral

region in H. brachysoma).

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36

3. Genus MYSTUS Scopoli, 1777

Mystus Scopoli, 1777, Introductio ad historiam naturalem: 451 (type speces: Bagrus

halepensis Valenciennes =Silurus pelusius Solander); Jayaram, 1959, Proc. First

All India Congr. Zool., (pt.2); 633; Jayaram, 1966, Int. Revue ges. Hydrobiol.,

51(3): 444-448 (Synopsis).

Diagnosis: Body short or moderately elongated and slightly compressed posteriorly.

Abdomen rounded. Head of moderate size, compressed or rather depressed. Snout

rounded or obtuse. Mouth sub terminal, transverse, moderately wide. Eyes moderately

large, supralateral, in anterior part of head not visible from below ventral surface and

with free circular margins. Lips thin. Jaws sub equal. Teeth uniformly villifom in bands

on jaws and palate, that on latter always uninterrupted (exception in M. horai). Four pairs

of barbels, one each of maxillary, nasal and two of mandibular, generally longer than

head. Gill membranes free from each other and also from isthmus. Branchiostegal rays 10

to 12.

Rayed dorsal fin inserted above last quarter of pectoral fins with seven rays and a

spine. Adipose dorsal fin low, of varying length. Pectoral fin with 6 to 10 rays, and a

spine serrated along inner edge with antrorse teeth. Pelvic fin with 6 rays. Anal fin short,

with 9 to 16 rays. Caudal fin forked, bilobed with unequal lobes: lobes may be rounded,

pointed or sometimes prolonged into filamentous extensions. Lateral line complete,

simple. An axillary pore generally present. Adipose dorsal fin is present and the length

varies with species.

Number of species: In India: 19

In Kerala: 8 (Mystus armatus, M. keletius, M. malabaricus, M.montanus, M.

oculatus, M. punctatus, M. cavasius, M. vittatus)

Habitat: Fresh water rivers. A few species enter the seas and estuaries.

Distribution: Syria in West Asia through India, Nepal, Pakistan to Sri Lanka in south,

through Bangladesh, Myanmar, Thailand, Indo China, Malaysia to East Indies and China

in the east.

Remarks: Roberts (1994) in a systematic revision of Asian bagrid catfishes restricted the

genera limits of Mystus sensu sticto to comprise 8 species only characterized by

moderately to very long maxillary barbels, very long adipose fin, total gill rakers on the

first gill arch 11 – 30 and total vertebrae 37-46 (about equally divided between abdominal

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and caudal vertebrae). Of the 8 species, Mystus bleekeri, Mustus cavasius and Mystus

rufescens are the only 3 species from Indian area considered as belonging to Mystus

sensu stricto. The remaining 16 species are considered as not belonging to Mystus in the

true sense. Jayaram and Anuradha (1999) have made a revision of the genus from its

entire world range. This restriction as applied by Roberts does not agree when data of the

four criteria: length of the maxillary barbels, length of the adipose fin, total gill rakers on

the first gill arch, and total vertebrae are tabulated; variations are seen. This has been

discussed in the above paper, and the problem requires a further study. It may however be

mentioned that other Bleekerian names as Aspidobagrus, Hemibagrus are available to

accommodate other species if need be.

Key to species of Mystus seen in Kerala

1) Occipital process extending to the basal bone of the dorsal fin……………….….

……….2

=Occipital process not extending to the basal bone of dorsal fin……………………..…..6

2) Adipose dorsal fin inserted immediately after the rayed dorsal fin (fig.17a);

Fig. 17a

[Maxillary barbels reach caudal fin base or beyond. Interorbital width more than 3.0 (2.0

to 3.0) in head length. A dark spot at base of caudal fin (fig.26) No bands on body]...........

............................................................................................................................M. cavasius

=Adipose dorsal fin inserted behind the rayed dorsal fin after a short distance (fig.18).......

…………………………………………………………………………………………….3

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Fig. 18

3) Median longitudinal groove reaching base of occipital process (fig.19) [ Median

longitudinal groove on head short, as two frontanelles, Adipose dorsal fin base

longer than anal fin base; A dark spot at the origin of dorsal fin; adipose dorsal fin short;

its base 1.2 times interdorsal distance; branchiostegal rays 11]……...…………………

…………………………………………………………………………………M. oculatus

Fig. 19

= Median longitudinal groove not reaching base of occipital process (Fig.20)…….…4

Fig. 20

4) Body plain without any shoulder spot or coloured bands on either side of lateral

line[Branchiostegal rays 10]………. ……………......…………......……….M.armatus

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= A coloured spot on the shoulder; Coloured bands on either side of lateral line. [Occipital

crest smooth. A dark blotch at base of caudal fin (fig.21). Adipose dorsal fin base longer

than anal fin base. Median longitudinal groove extending beyond posterior border of

orbit, and nearly reaching base of occipital process]......……………………...………..5

Fig. 21

5) Bluish shoulder spot; and a silvery line along the side ending in a dark spot at

base of caudal; one or two light bands along sides above lateral line [Eye diameter 3.5 to

4 times in head length; Pectoral fin with 6 soft rays]……………….……………...…M.

montanus

=A dark shoulder spot; body with 3 or 4 longitudinal colour bands(pale blue or dark

brown or black bands) above and below lateral line (fig.22)[ Eye diameter 4.5 to 6 times

in head length; Pectoral fin with 9 soft rays]………………………...............….M. vittatus

Fig. 22

6) Ten black rounded solid spots along lateral line (fig.23)[ Depth of body 7.8 to 8.4

times in standard length]……………………………………. …............………...M.

punctatus

=No such black rounded solid spots…………………………............………………...…7

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40

Fig. 23

7) Body depth 4 times in standard length; A light band above and below lateral line

(fig. 24),no spot at base of caudal fin; maxillary barbel extend to the middle of pelvic

fin…………………..........................................................................……………M. keletius

Fig. 24

= Body depth 4.5 to 6 times in standard length; A dark band only along the lateral line

ending with a dark blotch at base of caudal fin (fig.25); maxillary barbel extend to the

end of pelvic fin [Eye diameter 3.5 to 4.5 times in head length]…………………….……..

…………………………………………………………………………….M. malabaricus

Fig. 25

Species found in Kerala

1. Mystus armatus (Day)

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(Fig.21, Plate II – Fig.4)

Hypselobagrus armatus, Day, 1865, Proc. Zool. Soc. Lond.: 289 (type-locality: Cochin)

Macrones armatus: Day, 1877, Fishes of India: 450, pl. 101, fig. 3; Day, 1989, Fauna Br.

India, Fishes, 1: 161

Mystus (Mystus) armatus: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3:84.

Mystus armatus: Jayaram, 1977, Rec. zool. Surv. India Occ. Pap., (8): 28, fig. 23B.

Diagnosis: Occipital process exends to the basal bone of the dorsal fin. Median

longitudinal groove on the head as one or two frontelles not extending to the base of

occipital process. Maxillary barbels extend to the base of pelvic fins.

Habitat: Demersal; freshwater; brackish

Distribution: Wayanad range of hills, Western ghats, Bangladesh, Myanmar. Day 1865

reported as it is common in Karivannoor river in Trichur.

Local name: Kerala Mystus, Kotti (Mal.), Chillan koori (Mal.)

Remarks: The colour of the fish is leaden or brown above, lighter below, often with a

brown band along the flank. Upper half of dorsal fin darkish; anal fin with a dark band; a

dark blotch on base of caudal fin. It is of minor fishery value in Kerala where it is

obtained only occasionally. It attains a length of 14.5 cm SL.

2. Mystus keletius (Valenciennes)

(fig.24, Plate II – Fig.5)

Bagrus keletius Valenciennes, 1839, Hist. nat. Poiss., 14: 411 (type-locality:

Pondicherry).

Macrones keletius: Day, 1877, Fishes of India: 449, pl. 98, fig. 5; Day, 1889, Fauna Br.

India, Fishes, 1: 160

Mystus (Mystus) keletius: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 92.

Mystus keletius: Jayaram, 1977, Rec. zool. Surv. India Occ. Pap., (8): 31, fig. 26A.

Diagnosis: Occipital process not extending to the basal bone of the dorsal fin. Median

longitudinal groove on the head is not extending to the base of occipital process.

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Maxillary barbels extend to the middle of the pelvic fins. Adipose dorsal fin small and

bump like and its insertion considerably behind the rayed dorsal fin.

Habitat: Common in lowland water bodies.

Distribution: Western Ghats of Kerala, Tamilnadu and Sri Lanka (Misra, 1976),

Karnataka.

Local name: Keletius mystus

Remarks: Jayaram, 1999 reported that record from Punjab (Johal & Tandon, 1979) may

be misidentification. Found in rivers and ponds, commonly in muddy pools and tanks

(Menon, A. G. K., 1999). Adults usually occur among marginal vegetation or roots in

both still and slow-flowing waters.

3. Mystus malabaricus (Jerdon)

(Fig.25, Plate VI-Fig.18)

Bagrus malabaricus Jerdon, 1849, Madras Jour. Lit. & Sci., 15: 338 (type-locality:

mountain streams of Malabar).

Macrones malabaricus: Day, 1877, Fishes of India: 450, pl. 101, fig. 2; Day, 1889,

Fauna Br. India, Fishes, 1: 160.

Mystus maydelli Rossel, 1964, Mitt. Zool. Mus.Inst. Hamburg, 61: 149, fig. 1 (type-

locality: Bhima river at Wadgoan, Maharashtra); Jayaram, 1977, Rec. zool. Surv.

India Occ. Pap., (8): 32 (Status discussed).

Mystus (Mystus) malabaricus: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 93.

Diagnosis: Occipital process not extending to the basal bone of the dorsal fin. Median

longitudinal groove on the head not extending to the base of occipital process. Maxillary

barbel extend to the end of pelvic fins. Adipose dorsal fin long based and its insertion

behind the rayed dorsal fin after a short distance.

Habitat: Fresh water, mountain streams.

Distribution: India: Western Ghats from Karnataka, Kerala, Maharashtra,

Madhyapradesh and Assam. Common in Kabini, Chaliyar and Chalakudypuzha,

Karivannoorpuzha, streams in Parambikulam, Cheenkannipuzha and Achenkovil (Misra,

1976; Talwar and Jhingran, 1991; Easa and Basha, 1995; Jayaram 1981 a &1999).

Local name: Malabar mystus, Kallan koorie (Mal.)

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Remarks: Distinguished by a moderately long adipose fin, a deep caudal peduncle and a

dark midlateral stripe. This catfish which attains a length of 15 cm, contributes a minor

fishery in Kerala and Karnataka.

4. Mystus montanus (Jerdon)

(Plate II – Fig.6)

Bagrus montanus Jerdon, 1849, Madrs Jour. Lit. & Sci., 15(2) 337 (type-locality :

Manatoddy, Wynaad, Kerala State).

Macrones montanus : Day, 1877, Fishes of India : 449, pl. 101, fig. 4 ; Day, 1889, Fauna

Br. India, Fishes, 1: 159

Macrones montanus var. dibrugarensis Chaudhuri, 1913, Rec. Indian Mus., 8 : 254, pl.

9, figs 2, 2a, 2b (type-locality : Dibrugarh, assam) ; Jayaram, 1977, Rec. Zool.

Surv. India Occ. Pap., (8): 34 (Status discussed).

Mystus (Mystus) montanus : Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 97.

Mystus (Mystus) vittatus dibrugarensis : Misra, 1976, Fauna of India, Pisces (2nd ed.), 3:

107.

Diagnosis: Bluish shoulder spot; and a silvery line along the side ending in a dark spot at

base of caudal; one or two light bands along sides above lateral line

Habitat: Fresh water rivers, demersal; brackish.

Distribution: India: Assam, Kerala State, Wayanad range of hills, Madhyapradesh,

Hoshangabad district, Javadi Hills, Eastern Ghats.

Local name: Wynaadu mystus

Remarks: This species attains a length of 15 cm, is of minor interst to fisheries.

5. Mystus oculatus (Valenciennes)

(Plate VII-Fig.19)

Bagrus oculatus Valenciennes, 1839, Hist. nat. Poiss., 14: 424 (type-locality: Malabar).

Macrones oculatus : Day, 1877, Fishes of India: 448, pl. 98, fig. 4; Day, 1889, Fauna Br.

India, Fishes, 1: 156

Mystus (Mystus) oculatus: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 98.

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Diagnosis: Occipital process extends to the basal bone of the dorsal fin; Median

longitudinal groove on the head extends to the base of occipital process. Maxillary barbel

extend to the middle of anal fin. Adipose dorsal fin short and its insertion considerably

behind the rayed dorsal fin.

Habitat: Demersal; freshwater; brackish, Adults inhabit rivers in plains and estuaries

Distribution: Kerala and Tamilnadu (Misra, 1976), Coimbatore District.

Local name: Malabar mystus. Koorie (Mal.)

Remarks: According to Easa & Shaji, 1997, this species is considered very rare. This

small catfish which attains a length of 15 cm is of only minor fishery value in Kerala.

6. Mystus punctatus (Jerdon)

(fig.23)

Bagrus punctatus Jerdon, 1849, Madras Jour. Lit. & Sci., 15: 339 (type-locality: Cauvery

river, Western Ghats).

Macrones punctatus: Day, 1877, Fishes of India: 445, pl. 100, fig. 3; Day, 1889, Fauna

Br. India, Fishes, 1: 153.

Mystus maydelli (nec Rossel) David et al., 1969, Bull. Cent. Inland Fish. Res. Inst.,

Barrackpore, (13): 68.

Mystus (Mystus) punctatus: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 102

Mystus punctatus: Jayaram et al., 1982, Rec. zool. Surv. India Occ. Pap., (36): 87, fig. 27.

Diagnosis: Occipital process long but not extending to the basal bone of dorsal fin.

Median longitudinal groove extends to the base of occipital process. One row of 10 solid

spots present on the lateral side. Maxillaries extend to the end of the pelvic fin.

Habitat: Demersal; freshwater, Inhabits rapid rivers and streams

Distribution: India: Bhavani river at base of Nilgiri Hills, Karnataka and Kerala State. In

Kerala: Western Ghats. Common in Kabini river (Misra, 1976).

Local name: Nilgiri mystus

Remarks: Distinguished from its congeners by a unique combination of the following

characters: head length 28.1- 29.6% SL, head depth 11.9-14.3% SL, depth of the caudal

peduncle 8.8-9.9% SL, eye diameter 13.8-15% HL.

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7. Mystus cavasius (Hamilton – Buchanan)

(fig.26, Plate VIII-Fig.23)

Pimelodus cavasius Hamilton-Buchanan, 1822, Fishes of ganges: 203, 379, pl. 11, fig.

67 (type-locality : Gangetic provinces).

Macrones cavasius: Day, 1877, Fishes of India : 447, pl. 100, fig. 1 ; Day, 1889, Fauna

Br. India, Fishes, 1 : 155

Mystus mukherjii Ganguli and Datta, 1975, Zool. Soc. India B. S. Chauhan Comm. Vol.:

293 (type-locality : Subarnarekha river, Bihar).

Mystus (Mystus) cavasius: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 87, fig. 18.

Mystus cavasius : Jayaram, 1977, Rec. Zool. Surv. India Occ. Pap., (8): 29, fig. 21A.

Diagnosis: Adipose dorsal fin inserted immediately after the rayed dorsal fin. Occipital

process extends to the basal bone of the dorsal fin. Median longitudinal groove on the

head extends to the base of occipital process. Maxillary barbel extends beyond the base

of caudal fin.

Habitat: Found in tidal rivers and lakes; also canals, ditches, ponds, and inundated fields.

Distribution: Pakistan, India, SriLanka, Nepal, Bangladesh, Myanmar and Thailand

(Misra, 1976; Jayaram, 1981a &1999; Talwar and Jhingran, 1991). In Kerala it is

common in Chalakudy, Kabini and Chaliyar.

Local name: Gangetic mystus, Kotti (Mal.), Chillan koori (Mal.)

Remarks: Its pectoral spine can cause painful wounds (Talwar and Jhingran, 1991).

Found in the basin-wide tributary of the lower Mekong. Oviparous, distinct pairing

possibly like other members of the same family (Breder, C.M. and D.E. Rosen,

1966).

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46

Fig. 26

8. Mystus vittatus (Bloch)

(fig.22, Plate VII-Fig.20)

Silurus vittatus Bloch, 1797, Ichthyol. Hist. Nat., 11: 40, pl. 371, fig. 2 (type-locality:

Tranquebar, Tamil Nadu).

Macrones vittatus: Day, 1877, Fishes of India: 448, pl. 98, fig. 3, and pl. 99, fig. 4; Day,

1889, Fauna Br. India, Fishes, 1: 157.

Mystus (Mystus) vittatus vittatus: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 105,

Fig. 20

Diagnosis: Occipital process extends to the basal bone of the dorsal fin. Median

longitudinal groove on the head not extends to the base of the occipital process.

Maxillary barbels extend to the origin of anal fin.

Habitat: Demersal; freshwater; brackish; Adults inhabit standing and flowing waters.

Usually found among marginal vegetation in lakes and swamps with a mud

substrate.

Distribution: Throughout India, Pakistan, Bangladesh, Nepal, Myanmar, Thailand and

SriLanka.

Local name: Striped dwarf catfish, Manja koori (Mal.), Chillan Koori (Mal.)

Remarks: This species is included here as it is reported to be of distributed throughout

India. This is one of the most common, small sized catfishes caught in large quantities

from ponds, lakes, rivers, etc. in the Indian region. It attains a length of 21 cm in SL.

2. Family SILURIDAE

Sheat fishes

Diagnosis: Large sized, elongate fishes with a compressed body. Depressible teeth on

premaxillaries, mandible and vomer. Nostrils separated from each other by a short

distance, anterior tubular on tip of snout, posterior valved and situated before anterior

border of eyes. Barbels four to six, generally well developed. Nasal barbels invariably

absent. Gill openings very wide, extending upto lateral line, membranes free from each

other and isthmus. Branchiostegal rays 8-21.

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47

Rayed dorsal fin mostly one (two in Pinniwallago) short with four or five rays

and without a spine. Adipose dorsal fin absent. Paired fins laterally inserted. Pectoral fin

with a strong spine occasionally serrated. Anal fin very long, up to 93 rays extending

from just posterior to anal opening to caudal or confluent with it. Pelvic fins small, not

prominent, may be absent. Caudal fin rounded to weakly emarginated, with bluntly

rounded lobes, or forked. Lateral line straight, complete, and with short ventral branches,

dendritic or not, but no dorsal branches.

Air bladder large, attached to second to fourth vertebrae.

Lateral ethmoid with a slender posterior extension which meets a similar forward

extension of the sphenotic, so that frontal has no free edge, palatines reduced to a small

nodule, ecto-metapterygoids present, variously developed. Endopterygiod absent. Vomer

small dentigerous. Autopterotics and autosphenotics alone provide ventrally articular

facet for hyomandibular. Post temporals absent. Mesocoracoid in pectoral girdle present.

Ossified transcapular ligament antero-posteriorly compressed. Distal radials of

dorsal fin, pterygiophores absent. Articulations of anal fin rays with pterygiophores

shifted.

Vertebrae 52 to 74.

Habitat: Freshwater rivers

Distribution: World wide: India, Bangladesh, Indonesia, Malaya, Myanmar, Pakistan,

Srilanka, Thailand and Vietnam

In India: Of the five genera present in this family, three are reported from Kerala. They

are, Ompok, Wallago and Silurus. These three genera and 4 species (Ompok malabaricus,

Ompok bimaculatus, Silurus wynaadensis and Wallago attu) are discussed here with their

distribution in different parts of Kerala.

Key to Genera found in Kerala of the family Siluridae

1. Gape of the mouth very wide and very long, extending beyond eye

posteriorly(fig.27) [Eyes with free orbital rim, lying entirely above level of corner of

mouth, not visible from underside of head]

……………………………………………………................Wallago

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48

Fig. 27

= Gape of mouth not wide, not extending beyond eyes posteriorly (fig.28)................... 2

Fig. 28

2. Caudal fin rounded (fig. 29), truncate or weakly emarginate, medially with bluntly

rounded lobes; mandibular barbels one or two pairs; eyes not visible from below ventral

surface……............................................................................…....………………….Silurus

Fig. 29

= Caudal fin forked (fig.30). Mandibular barbels one pair; may be rudimentary. Eyes

visible from below ventral surface………….....……......................................…Ompok

Fig. 30

Genus OMPOK Lacepede

Ompok Lacepede, 1803, Hist. Nat. Poiss., 5: 49 (type species, Ompok siluroides

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49

Lacepede = Silurus bimaculatus Bloch); Haig, 1951, Rec. Indian Mus., 48(3/4):

108-112 (Review); Parameswaran, 1968, J. zoo. Soc. India, 19 (1/2): 90-94

(review).

Callichorus Hamilton-Buchanan, 1822, Fish of Ganges: 149 (type-species: Silurus

(callichorus) pabda Hamilton-Buchanan).

Diagnosis: Body elongated, compressed. Abdomen rounded. Head small, broad.

depressed. Snout bluntly rounded, depressed. Mouth superior, moderately wide, its cleft

oblique, not extending to front border of eyes (fig.28). Eyes small, their ventral border on

level with corner of mouth, visible from below ventral surface of head. Lips thin. Jaws

unequal, lower jaw prominent, more or less elevated at symphysis. Teeth uniformly

villiform, depressible in bands on jaws, in two separate patches on palate, no teeth on

palatines. Two pairs of barbels, one pair each of maxillary and mandibular; latter

occasionally rudimentary or small.

Rayed dorsal fin inserted above last half of pectoral fin, with three or five rays

and without any spine. Adipose dorsal fin absent. Pectoral fin with 11 to 14 rays and a

feebly serrated or smooth spine; its length surpassing pelvic fins, pelvic fins with six to

ten rays. Anal fin very long, with 52 to 75 rays, close to caudal fin, free from it. Caudal

fin forked. Lateral line complete, simple.

Number of species: In India: 4 species

In Kerala: 2 species Ompok bimaculatus (Bloch), Ompok malabaricus (Valenciennes)

Habitat: Fresh water

Distribution: India, Bangladesh, Borneo, Java, Myanmar, Nepal, Sri Lanka, Sumatra and

Thailand.

Key to species found in Kerala

1. Caudal lobes rounded, lower border of eye on level with cleft of mouth [Anal fin

with 63 to 69 branched rays]…...............….....................................................Ompok

malabaricus

= Caudal lobes pointed, lower border of eye below level of the clet of mouth [Anal fin

with 57 or 58 branched rays; maxillary barbells extend posteriorly to (or slightly beyond)

anal fin base]................………........................................................... Ompok bimaculatus

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1. Ompok bimaculatus (Bloch, 1794)

(fig.31, Plate III – Fig.7)

Silurus bimaculatus Bloch, 1797, Ichthyol. Hist. nat. des. Poiss., 11: 17, pl. 364 (type-

locality: Malabar).

Callichorus bimaculatus: Day, 1877, Fishes of India: 476, pl. 110, figs 4, 5; Day, 1889,

Fauna Br. India, Fishes, 1: 131, fig. 57.

Callichorus macrophthalmus (Blyth) Day, 1877, Fishes of India: 478, pl. 110, figs 2, 3;

Day, 1889, Fauna Br. India, Fishes, 1: 152.

Callichorus gangeticus (Peters) Day, 1877, Fishes of India: 476; Day, 1889, Fauna Br.

India, Fishes, 1: 130.

Callichorus sindensis Day, 1877, Fishes of India: 476, pl. 110, fig. 1 (type-locality: Sind,

Pakistan); Day, 1889, Fauna Br. India, Fishes, 1: 130, Talwar, 1991, J. Inland

Fish Soc. India (in press) (Status discussed).

Ompok bimaculatus: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 189, fig. 35.

Ompok canio (Hamilton-Buchanan) Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 192;

Coad, 1981, Nat. Mus. Nat. Sci. Ottawa, (14): 15.

Ompok sindensis: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 198.

Fig.31

Diagnosis: Dorsal fin with 4 branched rays and anal fin with 57-58 branched rays.

Maxillary barbels extend slightly beyond the anal fin origin. Colour silvery shot with

purple. A large dusky spot present at the shoulder region.

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51

Habitat: Fairly common in the rivers, streams and water bodies in the low lands. Occurs

in streams and rivers of all sizes with currents ranging from sluggish to moderate. Found

in quiet, shallow (0.5-1.5 m), often muddy water, in sandy streams, rivers and tanks

(Pethiyagoda, R. 1991). Also occurs in canals, beels and inundated fields. Moves into

freshly inundated habitats during the flood season

Distribution: Throughout India, Afganistan, Pakistan, Sri Lanka, Myanmar, Thailand,

Java, Sumatra, Borneo, China, Bangladesh, Malaya, Nepal, Vietnam and Yunnan.

Local name: Indian butter catfish

Remarks: It is considered a very tasty fish and is highly priced. It spawns during the

monsoons and thrives well in confined waters. It attains a length of 45 cm in SL.

2.Ompok malabaricus (Valenciennes)

(Plate III – Fig. 8)

Silurus malabaricus Valenciennes,1839, Hist. Nat. Poiss., 14: 353 (type-locality :

Malabar).

Callichorus malabaricus: Day. 1877, Fishes of India: 478, pl. 111, fig. 1; Day, 1889,

Fauna Br. India, Fishes, 1: 133.

Silurus goae Haig, 1951, Rec. Indian Mus., 48 (3/4) : 77, fig. 1 (type-locality : Goa and

Trivandrum) ; Jayaram, 1981, Handbook zool. Surv. India, (2): 211 ; Talwar,

1991, J. Inland Fish. Soc. India : (in press) (gangetic relationship and status

discussed).

Ompok malabaricus : Misra, 1976, fauna of India, Pisces (2nd ed.), 3: 193.

Diagnosis: Dorsal fin with 4 and anal fin with 63-69 branched rays. Maxillary barbels

extend slightly beyond the pelvic fin origin. Colour brown shot with purple. A large

dusky spot present at the shoulder region. Fins dusky.

Habitat: Found in rivers in plains and submontane regions. Common in rivers and

wetlands

Distribution: India: Known only from Goa and Kerala.

Local name: Goan catfish

Remarks: This catfish attains a length of 51 cm in SL; its interest to fisheries is not

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presently known.

2. Genus WALLAGO Bleeker, 1851

Wallago Bleeker, 1851, Natuurk. Tijdschr. Ned.-Indie, 1: 265 (type-species: Silurus

mulleri Bleeker = Silurus attu Schneider); Roberts, 1982, Copeia, (4): 890-894

(revision).

Wallagonia Myers, 1938, Copeia, (2): 98 (type-species: Wallago leerii Bleeker).

Diagnosis: Body elongated, laterally compressed. Abdomen rounded. Head fairly large,

deep and depressed. Snout spatulate, somewhat protruded. Mouth subterminal, oblique,

gape wide, reaching to or beyond anterior border of eyes (fig.27). Eyes small, with free

orbital margins above level of corner of mouth, not visible from below ventral surface.

Lips thin. Jaws subequal, lower jaw longer prominent. Teeth villiform in bands in jaws

and in patches on palate. Two pairs of barbels, one pair each of maxillary and

mandibular.

Rayed dorsal fin inserted above half of pectoral fin, with five rays and without a

spine. Adipose dorsal fin absent. Pectoral fins with 13 to 15 rays and a feeble, smooth

spine. Pelvic fins with 8 to 10 rays. Anal fin long with 72 to 96 rays free from caudal fin.

Caudal fin deeply forked with rounded lobes. Lateral line complete, well marked, simple.

Number of species: Only one species reported so far from India and kerala, Wallago attu.

Habitat: Freshwater habitat.

Distribution: India, Bangladesh, Java, Kampuchea, Malay peninsula, Myanmar,

Pakistan, Sri lanka, Sumatra, Thailand and Vietnam.

Species found in Kerala

1. Wallago attu (Bloch & Schneider)

(fig.32)

Silurus attu Schneider, 1801, Syst. Ichth.: 378, pl. 75 (type-locality: Malabar).

Wallago attu: Day, 1877, Fishes of India: 479, pl. 111, fig. 4; Day, 1889, Fauna Br.

India,

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53

Fishes, 1: 126, fig. 54; Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 206, fig.

41.

Wallagonia attu: Hora, 1939, J. Bombay nat. Hist. Soc., 41(1): 64, pl. Redescription).

Wallagu attu valeya Deraniyagala, 1953, Spolia zeylan., 27: 15 (type-locality: Yakvala,

Ceylon); Roberts, 1982, Copeia, (4): 891 (Status clarified).

Fig. 32

Diagnosis: Dorsal fin with five and anal fin with 74-93 branched elements. Barbels two

pairs. Maxillary barbels extend beyond the origin of anal fin.

Habitat: Found in large rivers, lakes and tanks. A large, voracious and predatory catfish

which thrives in heels with grassy margin; mostly hides under holes in river banks and

canals. Associated with deep, still or slow-flowing water with a mud or silt substrate.

Sluggish and stays on muddy or silty bottom in search of food.

Distribution: India, Myanmar, Thailand, Vietnam, Kampuchea, Malay Peninsula, Java

and Sumatra.

Local name: Boal, Valla (Mal.), Manjavalla (Mal.), Thooli.

Remarks: This catfish is a good sport and can be easily taken on a hook with dead or live

bait. It is very destructive to other more valuable food fishes such as the major carps. It

grows to about 2 m and wighs more than 45 kg. It is rather sluggish and stays at the

bottom of water in search of food. If handled it bites strongly as it has a huge mouth with

formidable jaws, armed with bands of conical teeth. Due to its rich oil content it is liked

by many.

3. Genus SILURUS Linnaeus

Silurus Linnaeus, 1758, Syst. Nat. Ed. 10, p.301 (type species, Silurus glanis Linnaeus,

by subsequent disgnation by Bleeker, 1862, p.393).-kobayakawa, 1989, Jap. J.

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54

ichthyol., 36(2), 155-184 (revision).

Diagnosis: Body elongated, compressed. Abdomen rounded. Head small, broad,

depressed. Snout obtusely rounded. Mouth terminal, horizontal to somewhat oblique,

wide, gape of mouth reaching to below eyes. Eyes small, covered with skin above level

of angle of mouth not visible from below ventral surface. Lips thin. Jaws subequal. Teeth

uniformly villiform in bands on jaws and in one or two patches on palate. Two or three

pairs of barbels, one pair maxillary, rather heavy, flattened one or two pairs mandibular.

Rayed dorsal fin very small, inserted above tip of pectoral fins, with two to five

rays and without a spine. Adipose dorsal fin absent. Pectoral fins with 7 to 11 rays and a

spine whose anterior surface is smooth, granulated or serrated, but its posterior surface

strongly serrated in males, and weakly serrated or smooth in females. Pelvic fins with 7

to 10 rays. Anal fin very long based with 58 to 74 rays, confluent with caudal fin with a

distinct notch between them; anal rays covered by integument for most of their length.

Caudal fin rounded or truncate, with bluntly rounded lobes. Lateral line complete, simple.

Number of species: Only one species is reported from both India and Kerala. Silurus

wynaadensis Day

Habitat: Freshwaters of palearctic region, brackish.

Distribution: Assam, Eastern Himalaya, Western Ghats in Peninsular India and

Myanmar. Distributed throughout Eurasia except the central region (Talwar and jhingran,

1991)

Species found in Kerala

1. Silurus wynaadensis Day, 1873

(fig.33, Plate III – Fig.9)

Silurus punctatus Day, 1868, Proc. Zool. Soc. Lond.: 155 (type-locality: Wynaad, Kerala)

(name preoccupied by Silurus punctatus Cantor, 1842).

Silurus wynaadensis Day, 1873, Proc. Zool. Soc. Lond.: 237 (replacement name for

Silurus punctatus Day); Day, 1877, Fishes of India: 480, pl. 111, fig. 6; Day,

1889, Fauna Br. India, Fishes, 1: 119, fig. 50; Hora, 1937, Rec. Indian Mus.,

39(3): 342, fig. 8a.

Silurus cochinchinensis wynaadensis: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3:

202, Fig. 40.

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Fig. 33

Diagnosis: Barbels three pairs, Maxillary barbels extend beyond the pectoral fins. Anal

fin with 54-56 branched elements, caudal fin rounded.

Habitat: Occurs in fast flowing rivers, canal and streams, hides in holes and rocks

Distribution: Wayanad, Thung Bhadra river system (Shaji & Easa 2001).

Local name: Malabar silurus.

Remarks: It is a specis known only from South India. The colour of the fish is, in life,

leaden becoming purplish below with minute dots scattered over entire body;

occasionally a dusky finger-like mark on shoulder. This species attains a length of 30 cm;

of no interst to fisheries in Kerala.

3. Family SCHILBEIDAE

Schilbid Catfishes

Diagnosis: Medium to large sized fishes with a compressed body. Teeth on

premaxillaries, mandible and vomer. Nostrils widely separated, anterior wide, along front

border of snout; posterior slit-like or with a flap or simple, nearer eye than tip of snout.

Barbels two, four or eight, fairly well developed (vestigial or absent in Silonia). Gill

openings very wide, extending upto lateral line, membranes free from each other and also

from isthmus. Branchiostegal rays 5 to 12.

Rayed dorsal fin when present short, with five to seven rays and a spine, may be

absent also. Adipose dorsal fin generally present, may be absent. Paired fins inserted

laterally. Pectoral fins with a strong spine usually serrated. Anal fin very long, not

confluent with caudal fin. Caudal fin forked. Lateral line generally complete, simple.

Air bladder of varying types and shapes.

Lateral ethmoid facet for articulation of palatines more lateral than ventral. Palatines

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56

rod-like, broad. Endopterygoid occasionally present (Silonia). Ectopterygoid toothed.

Metapterygoid may have sutural contact with hyomandibular (exception Psedeutropius,

Neotropius). Autopterotics and autosphenotics provide ventrally articular facet for

hyomandibular, but variable; temporals present, connected to skull by sutures. Lower

limb of post-temporal moderate to well developed.

Vertebrae 47 to 58.

Habitat: Fresh water

Distribution: India, Africa, Malaya, Myanmar, Pakistan and Thailand.

Subfamily: 2 subfamilies are seen in family Shilbeidae, Subfamily Ailinae with dorsal fin

absent and Subfamily Schilbeinae with dorsal fin present. So far only the members of

subfamily Schilbeinae are reported from Kerala.

Subfamily SCHILBEINAE

Diagnosis: Dorsal fin and spine present. Adipose dorsal fin vestigial, small, may be

absent. Teeth on vomer large. Anal fin moderate.

Six vertebrae from the pars sustenaculum. Central limits of vertebra clear. Dorsal

lamina when present does not form an oblique ridge of bone. Cardinal groove may be

present or absent. Lateral process of supraethmoid extends over half of each premaxillae.

Inferior limb of post-temporal present. Sphenotic forms nerve foramen for the 7 th cranial

nerve.

Number of genera found in Kerala: 3 genera are so far reported from Kerala. They are

Pseudeutropius, Proeutropiichthys and Silonia

These 3 genera and their corresponding 3 species are discussed here with their

distribution in different parts of Kerala.

Key to genera of Schilbeinae found in Kerala.

1. Two or four barbels often vestigial or absent; nasal and one pair of mandibular

barbels absent.Teeth on jaws

caniniform…............................................................................Silonia

= Eight barbels. Teeth on jaws villiform……..........................………………….....……2

2. Caudal fin bent downwards from caudal peduncle onwards. Teeth on palate in

four small distinct patches which may be continuous, slightly separated or wide apart

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57

from each other[Air bladder of moderate size]……..

………………………............Proeutropiichthys

= Caudal fin normal, not bent downwards. Teeth on palate in two extensive patches.

[Cleft of mouth not oblique (Fig. 34);

Fig. 34

teeth on upper jaw not exposed; jaws not wide; Teeth on palate in two separate patches

(fig.35), widely separated which may be connected by a linear series. Posterior nostrils

narrow [Air bladder large]……………………………................................Pseudeutropius

Fig. 35

1. Genus PSEDEUTROPIUS Bleeker

Pseudeutropius Bleeker, 1862, Verh. Akad. Amsterdam, 14, p.398 (type species,

Eutropius brachypopterus Bleeker, Hora, 1941, Rec. Indian. Mus., 43 (2): 100-

105 (review).

Diagnosis: Body elongate, compressed, herring-shaped. Part of abdomen more or less

keeled. Head short, compressed. Snout sharp, conical, not pointed. Mouth wide,

subinferior, transverse, overhung by snout, moderately wide, its cleft not extending to

anterior border of eyes. Eyes large, ventro-lateral, partly below and behind level of cleft

of mouth with broad circular adipose lids, visible from below ventral surface. Lips thin.

Jaws subequal, upper jaw longer. Teeth small, villiform, in narrow bands on jaws and

palate; those on latter in two small widely separated but narrow patches, occasionally

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58

connected by a linear series. Four pairs of barbels: one each of maxillary, nasal and two

of mandibular.

Rayed dorsal fin short, inserted above half of pectoral fin with five or six rays and

a spine. Adipose dorsal fin short, posteriorly free. Pectoral fins with seven to nine rays

and a spine serrated along both margins. Pelvic fins with 6 rays. Anal fin long based, with

30-46 rays, not confluent with caudal. Caudal fin forked. Lateral line complete, simple.

Air bladder oval, slightly longer than broad, lying free in abdominal cavity,

supported anteriorly by bony vertebral elements, thin-walled, in contact with abdominal

skin above each pectoral fin, forming transluscent blister-like area.

Number of species: In India: 2

In Keala: 1 (Pseudeutropius mitchelli)

Habitat: Freshwater

Distribution: Widely distributed in the oriental region (Talwar and Jhingran, 1991;

Jayaram, 1981). Seen throughout India, Pakistan, Nepal, Bangladesh and Myanmar.

Species found in Kerala

Pseudotropius mitchelli Gunther

(fig.36)

Pseudeutropius mitchelli Gunther, 1864, Cat. Fishes Br. Mus., 5: 59 (type-locality:

“Madras Presidency”); Hora, 1941, Rec. Indian Mus., 43(2): 104(Identity

discussed); Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 181.

Pseudeutropius sykesii (nec Jerdon) Day, 1877, Fishes of India: 473, pl. 109, fig.5; Day,

1889, Fauna Br. India, Fishes, 1: 140.

Fig. 36

Diagnosis: Anal fin with 32-34 branched elements. Barbels 4 pairs. Maxillary barbels

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59

extend about the middle of pelvic fins. Bluish silvery along the back becoming silvery on

the flanks. Dorsal and caudal fins grayish.

Habitat: Freshwater

Distribution: This endemic species is very rare. 3 specimens are reported from Periyar

and Chaliyar (Shaji &Easa, 2001)

Local name: Malabar patashi, Vellivallah (Mal.)

Remarks: This species is found only in the fresh waters of Kerala. It attains a length of

90 cm, is of no interst to fisheries. It is in fact a rather rare species.

Key to species: Maxillary barbels extend up to the midway of pelvic fin. Eye diameter

3.0 to 3.5 in head length. Nape slightly elevated. Teeth on palate in two small oval

patches.

2. Genus PROEUTROPIICHTHYS Hora

Proeutropiichthys Hora, 1937, Curr. Sci., 5, 353 (type–species, Eutropius

macrophthalmus Blyth); Hora, 1941, Rec. Indian Mus., 43 (2): 105-110 (Review);

Talwar, 1991, Copeia (in Press) (Review).

Diagnosis: Body elongate, compressed; herring –shaped; part of abdomen more or less

keeled. Head short, oval, compressed. Snout broad, rounded, nearly on a line with level

of back. Mouth subterminal, small, crescentic, cleft slightly ascending. Eyes

conspicuously large ventro-lateral, in anterior half of head visible from below ventral

surface. Lips thin. Jaws subequal, lower jaw broadly pointed in middle. Teeth small,

villiform in bands on jaws and in four oval patches forming a semilunar band on palate.

Four pairs of barbels, one each of maxillary, nasal and two of mandibular.

Rayed dorsal fin inserted above last quarter of pectoral fins, with six to eight rays

and a spine. Adipose dorsal fin short, posteriorly free. Pectoral fins with 8 to 11 rays and

a spine serrated along both margins. Pelvic fins with six rays. Anal fin long with 42 to 52

rays, not confluent with caudal. Caudal fin deeply forked, bent downwards from caudal

peduncle. Lateral line complete, simple.

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60

Air bladder not extensive, moderate sized, lying free in abdominal cavity.

Number of species: In India: 1 species with two sub species

In Kerala: 1 species (Proeutropiichthys takree takree)

Habitat: Fresh water

Distribution: Widely distributed in the oriental region (Talwar and Jhingran, 1991).

India, Deccan, Myanmar

Species found in Kerala

Proeutropiichthys takree takree (Sykes)

(Fig. 37)

Hypophthalmus taakree Sykes, 1838, Proc. Zool. Soc. Lond., (pt.6): 163; Sykes, 1841,

Trans. Zool. Soc. Lond., 2: 369, pl. 64, fig. 4 9type-locality: Beema river nr. Pairgoon,

Maharashtra).

Schilbe sykesii Jerdon, 1849, Madras Jour. Lit. Sci., 15: 335 (type-locality: Cauvery

river); Hora, 1941, Rec. Indian Mus., 43(2):105 (status discussed).

Pseudeutropius taakree: Day (partim), 1877, Fishes of India: 471, pl. 109, fig. 4; Day

(partim), 1889, Fauna Br. India, Fishes, 1:138.

Proeutropiichthys taakree: Misra (partim), 1976, Fauna of India, Pisces (2nd ed.), 3: 176.

Fig. 37

Diagnosis: Dorsal fin with 6-8 and anal fin with 40-50 branched elements. Barbels four

pairs and the maxillary barbels extend up to the pelvic fins, colour silvery.

Habitat: Found in freshwater and tidal rivers

Distribution: India: Western Ghats, Kerala, And Maharashtra

Local name: Indian takree

Remarks: The colour of the species is silvery when it is caught in life. It is distributed in

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the Peninsular India. This catfish attains a length of 40 cm SL and is of minor interest to

fisheries.

3. Genus SILONIA Swainson

Silonia Swainson, 1839, Natural History Animals, Fishes, 2 : 305 (type-species : Silonia

lurida Swainson = Pimelodus silondia Hamilton – Buchanan) ; Hora, 1938, J.

Bombay nat. Hist. Soc., 40(2) : 137-147 (Review).

Silundia Valenciennes, 1840, Hist. Nat. Poiss., 15 : 49 (type-species : Pimelodus silondia

Hamilton-Buchanan).

Silonopangasius Hora, 1937, Curr. Sci., 5 : 352 (type-species : Ageneiosus childreni

Sykes) ; Silas, 1952, Proc. Nat. Inst. Sci. India, 18 (5) : 433 (Status discussed).

Diagnosis: Body elongate, compressed. Abdomen rounded. Head moderate sized,

compressed, anteriorly rounded. Snout obtusely rounded. Mouth anterior, wide, obliquely

directed upwards. Eyes moderate sized, situated laterally behind angle of mouth, visible

form below ventral surface. Posterior nostril enlarged medial to anterior one and

transversely oriented. Lips thin. Jaws equal. Highly specialized, enlargedcanine teeth

onjaws, villiform on palate; jaw teeth project outside mouth opening (Fig.38). Two pairs

of barbels; one of maxillary, small, in a groove; one of mandibular; either of the pair may

become vestigial or absent.

Rayed dorsal fin inserted above half of pectoral fins with 7 rays and a spine.

Adipose dorsal fin short, posteriorly free. Pectoral fins with 11 to 13 rays and a strong

spine serrated along both edges. Pelvic fins with 6 rays. Anal fin long with 40 to 46 rays.

Caudal fin deeply forked. Lateral line complete, indistinct.

Air bladder generally reduced, tick walled, not enclosed in bone.

Habitat: Inhabits estuaries, also ascending large rivers.

Distribution: India, Bangladesh, Myanmar and Nepal

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Fig. 38

Species found in Kerala

1. Silonia childreni (Sykes)

Ageneiosus childreni Sykes, 1838, Proc. Zool. Soc. Lond., (pt. 6): 165; Sykes, 1841,

Trans. Zool. Soc. Lond., 2: 375 (type-locality: Mula Mutha river nr. Poona).

Silundia sykesii Day, 1876, Trans. Linn. Soc. (Zool), 12: 569 (type-locality: Krishna

river.); Day, 1877, Fishes of India: 487, pl. 114, fig.2; Day, 1889, Fauna Br.

India, Fishes, 1: 144.

Silonopangasius childreni: Hora, 1941, Rec. Indian Mus., 43(2): 98, fig. 1c.

Silonia childreni: Silas, 1952, Proc. Nat. Inst. Sci. India, 18 (5): 433; Misra, 1976, Fauna

of India, Pisces (2nd ed.), 3: 183 (nec fig. 33)

Diagnosis: Barbels two pairs, nasal and maxillaries; maxillaries extend up to the

operculam or little beyond. Bluish on the back and whitish on the flanks and abdomen.

Air bladder large (Fig. 39), longer axis transversely disposed. Mandibular barbels equal

to the diameter of eyes.

Fig. 39

Habitat: Fresh water, Occur in large rivers and reservoirs

Distribution: It is reported to occur in Western Ghats, Krishna and Godavari river

systems (Talwar and Jhingran, 1991). Also reported from Cauvery river systems.

Local name: White catfish

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Remarks: It attains a length of 48 cm and forms an important food fish in Maharashtra. It

is a dominant species in the catches from deep waters, especially during the monsoon

months (April-July). This species is a highly predaceous fish in the Cauvery river

damaging stocks of Gonoproktopterus dubius, etc.

4. Family SISORIDAE

Sisorid catfishes

Generally small to medium sized fishes with head and anterior part of body

depressed, and tail compressed or entire body compressed. An adhesive apparatus on

thorax may be present or absent. Teeth on premaxillaries and mandible; palate edentate.

Nostrils close together, slit-like, separated by nasal barbel of varying lengths. Barbels

eight, generally well developed, in some genrea thick, fleshy with broad bases. Gill

openings wide or narrow , restricted to sides; free or confluent with isthmus.

Rayed dorsal fin short, with or without a spine. Adipose dorsal fin smooth,

generally free, but in some genera confluent with caudal, in some rudimentary,

represented by a small short spine (Sisor). Paired fins inserted horizontally, may or may

not be plaited below. Pectoral fins with or without a spine, denticulated either on inner or

outer margin, or on both; in some genera outermost ray pinnate, cartilaginous, a spine in

typical sense being absent; outermost ray of pelvic fins thick, pinnate. Anal fin short, not

confluent with caudal. Caudal fin deeply forked, emarginated, truncate or rounded.

Lateral line present, complete.

Air bladder small, partly enclosed in a bony capsule.

Lateral ethmoid facet for articulation of palatines more lateral than ventral.

Palatines very well developed, broad. Endopterygoid absent, ecto and meso-pterygoid

present, variously developed. Metapterygoid connected to hyomandibular. Prevomer

small, edentate. Autosphenotics alone provide ventrally the articular facet for

hyomandibular. Post-temporals present, united to skull with sutures, with inferior limb

weak, fused to basioccipital.

Vertebrae 34-40.

Habitat: Fresh water

Distribution: India, Bangladesh, China, Malaya, Myanmar, Nepal, Pakistan, Thailand,

and Vietnam. Not known so far from Sri Lanka.

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Number of genera: 18 genera are so far reported from India. But only a single genus is

reported from Kerala, Glyptothorax.

Genus GLYPTOTHORAX Blyth

Glyptothorax Blyth, 1861, J. Asiat. Soc. Beng., 29: 154 (type species: Glyptothorax

trilineatus Blyth); Hora, 1923, Rec. Indian Mus., 25 (1): 8-44 (Binomics); Menon,

1954, Rec. Imdian Mus., 52 (1): 27-54 (Revision); Li, 1986, Indo-Pacific Fish

Biology: 521-528 (Synopsis).

Superglyptothorax Li, 1986, Indo-Pacific Fish Biology: 524 (type-species: Glyptothorax

coheni Ganguly, Datta and Sen).

Paraglyptothorax Li, 1986, Indo-Pacific Fish Biology: 524 (type-species: Glyptosternum

pallozonum Lin).

Diagnosis: Body elongate, moderately or greatly depressed. Body smooth or rough with

granules or tubercles. Abdomen slightly flat to rounded. Head small, covered with thick

skin, depressed. Snout conical, not pointed. Mouth inferior, transverse, narrow. Eyes

dorsal, small, not visible from below ventral surface. Lips thick, fleshy, papillated. Jaws

subequal, upper jaw the longer. Teeth villiform in jaws; palate edentate. Ventral surface

of body provided with an adhesive apparatus with or without a central pit or depression

on thorax. Four pairs of barbels; one pair each of maxillary, nasal and two of mandibular;

maxillary pair with broad bases. Gill membranes united with each other and also with

isthmus. Cubito-humeral and scapular processes indistinct, covered by skin.

Rayed dorsal fin inserted above half of pectoral fins with 5-7 rays and a spine.

Adipose dorsal short, high, posteriorly free. Pectoral fins with 6-11 rays and a spine,

strong, broad, serrated with antrorse teeth along inner edge. Fins may be enveloped in

skin. Pelvic fins with six rays. Paired fins may be plaited below. Anal fin short, with 7 to

14 rays. Caudal fin deeply forked. Lateral line complete, simple.

Air-bladder enclosed in bone.

Habitat: Fresh water

Distribution: India, Bangladesh, East Indies, Iraq, Myanmar, Nepal, Pakistan and

Thailand.

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Number of species: 32 species are reported from India, in which 5 species are reported

from Kerala.

Key to species of Glyptothorax seen in Kerala

1. Adhesive apparatus on thorax as long as broad or broader than long (fig 40);

Adhesive apparatus feebly developed [Body with three white transverse bands]

……………………………………………………………………G. anamaliensis

Fig. 40

= Adhesive apparatus on thorax longer than broad (Fig. 41); Adhesive apparatus well

developed extending forwards to a point between union of gill membranes to isthmus

…………......……………….......................……........…….2

Fig. 41

2. Occipital process not reaching basal bone of dorsal fin (fig. 42); [Paired fins

pliated ventrally (fig. 43); maxillary and nasal barbels long, dorsal fin nearer to snout tip;

Nasal barbells extend beyond eye; Maxillary barbels extend for some distance beyond

upper angle of gill openings]………...................................................……......………..G.

housei

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Fig. 42

Fig. 43

= Occipital process reaching basal bone of dorsal fin (fig. 44)…….................…………..3

Fig. 44

3. Least height of caudal peduncle 2.6 to 2.7 in its length. Body with two light

longitudinal bands [Pectoral spine shorter than head length]……..............…..........

…….G. annandalei

= Least height of caudal peduncle 1.5 to 2.0 in its length. Body without bands………….4

4. Paired fin plaited (fig. 43). Skin granulated. Rayed dorsal fin height 1/4depth of

body [Pectoral spine equal or more than head length]....………………….……............G.

lonah

= Paired fins not plaited (fig. 45). Skin smooth or occasionally tuberculated. Rayed dorsal

fin height 1.0 to 1.3 times depth of body................................................G. madraspatanum

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Fig. 45

Species found in Kerala

1. Glyptothorax anamaliensis Silas

(Fig. 46)

Glyptothorax anamalaiensis Silas, 1951, J. Bombay nat. Hist. Soc., 50(2): 370 (type-

locality: Anamai Hills, Western Ghats); Jayaram, 1979, Rec. zool. Surv. India

Occ. Paper, (14): 34, figs 24 A, B (after Silas).

Fig. 46

Diagnosis: Maxillary barbels extend beyond the base of pectoral fins. Adhesive thoracic

apparatus feebly developed. Body with three transverse white bands. One at the dorsal

origin, second at the origin of the adipose dorsal and third one at the bifurcation of the

caudal peduncle.

Habitat: Fresh water, Found in mountain rapids

Distribution: Anamalai Hills and Chaliyar rivers in the Western Ghats of Kerala (Silas,

1951; Easa and Basha, 1995)

Local name: Anamalai sucker catfish

Remarks: This species is common in the streams at base of the Anamalai hills (Kerala)

but is of no interst to fisheries. It attains a length of about 10 cm.

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2. Glyptothorax annandalei Hora, 1923

(Fig. 47, Plate VII Fig.21, Plate VIII-Fig.22)

Glyptothorax annandalei Hora, 1923, Rec. Indian Mus., 25(1): 14, pl. 1, fig. 3 (type-

locality: Bhavani river at base of Nilgiri Hills); menon, 1954, Rec. Indian Mus.,

52(1): 52; Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 258, pl. 11, fig. 1;

Jayaram, 1979, Rec. zool. Surv. India Occ. Paper, (14): 34, fig. 30A.

Diagnosis: Occipital process reaching basal bone of dorsal fin. Maxilary barbels extend

beyond the base of pectoral fins. Adhesive thoracic apparatus well developed. Body dark

with two longitudinal stripes along the flanks.

Fig. 47

Habitat: Found attached to the rocks, boulders and bed rocks of the fast flowing clear

rapids. Crabs are the major predators of this species.

Distribution: Bhavani river at the base of Nilgiris (Hora, 1923), South India, Western

Ghats Vindhya mountains and Nepal. In Kerala it is known from Kunthi, Kabini and

Periyar river (Rema Devi and Indra, 1986; Easa and Basha, 1995; Arun et al. 1996; Gopi,

1998).

Local name: Annadale’s sucker catfish

Remarks: This catfish attains a length of 11.5 cm; of no interest to fisheries.

3. Glyptothorax housei Herre, 1942

(Plate IV – Fig.10)

Glyptothorax housei Herre, 1942, Stanford Ichthyol. Bull., 2(4): 117, fig. (type-locality:

Anamalai Hills, Western Ghats); Silas, 1951, J. Bombay nat. Hist. Soc., 50: 369;

Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 267.

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Diagnosis: Occipital process not reaching the basal bone of dorsal fin. Maxillary barbels

slightly beyond the base of pectoral fins. Adhesive thoracic apparatus well developed.

Body pinkish or reddish with yellow or dusky mottling. Dorsal fin inserted nearer to the

snout tip than the base of the adipose dorsal fin.

Habitat: Fresh water, Found in mountain rapids

Distribution: Western Ghats- Anamalai Hills, Puthuthottam estate, Kerala (Herre, 1945)

Local name: Herre’s sucker catfish

Remarks: This catfish attains a length of 10 cm; of no interest to fisheries.

4. Glyptothorax lonah (Sykes, 1839)

(Fig. 48a & 48b, Plate IV – Fig.11)

Bagrus lonah Sykes, 1838, Proc. Zool. Soc. Lond., (pt. 6): 164 (type-locality: Deccan).

Glyptosternum lonah: Day (partim), 1877, Fishes of India: 496, pl. 113, fig. 5; Day

(partim),1889, Fauna Br. India, Fishes, 1: 196, fig. 72.

Glyptothorax dekkanensis (Gunther) Hora, 1923, Rec. Indian Mus., 25(1): 24, fig. 3.

Glyptothorax lonah: Hora, 1938, Rec. Indian Mus., 40(4): 371, pl. 7 figs 1, 2 (Systematic

position discussed); Misra, 1976, Fauna of India, Pisces (2 nd ed.), 3: 270, pl. 11,

figs. 7 & 8.

Fig. 48a

Diagnosis: Adhesive thoracic apparatus well developed. Maxillary barbels extend

posteriorly to the middle of the pectoral fin. Yellowish brown above and lighter below. A

light strek along the lateral line present (Hora, 1938).

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Fig. 48b

Habitat: Fresh water

Distribution: Deccan, Godavari and Krishna river systems. In Kerala it is known from

Chalakudy River (Hora, 1938; Ajithkumar et al. 1999).

Local name: Deccan sucker catfish

Remarks: This catfish bears a close resemblance to the goonch, Bagarius bagarius. When

a fleshy caught and alive, the colours are strikingly beautiful. It attains a length of about

15 cm; of no interest of fisheries.

5. Glyptothorax madrapatanum (Day)

(Fig. 49)

Glyptosternum madraspatanum Day, 1873, J. Linn. Soc. Lond., 11: 526 (type-locality:

Bhavani river at base of Nilgiri Hills); Day, 1877, Fishes of India: 498, pl. 116,

fig. 4; day, 1889, Fauna Br. India, Fishes, 1: 200.

Glyptothorax madraspatanum: Menon, 1954, Rec. Indian Mus., 52(1): 31

(Redescription); Misra, 1976, Fauna of India, Pisces (2nd ed), 3: 27; Jayaram,

1979, Rec. zool. Surv. India Occ. Paper, (14): 40, fig. 27.

Glyptothorax madraspatanus: Hora and Law, 1941, Rec. Indian Mus., 43(2): 255.

Diagnosis: Adhesive thoracic apparatus well developed. Occipital process reaching the

basal bone of dorsal fin. Maxillary barbels extend posteriorly to the base of the pectoral

fins. Body dark with three yellowish bands.

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Fig. 49

Habitat: Fresh water, Occurs in mountain rapids, benthopelagic.

Distribution: Western Ghats and Mettuppalayam in Coimbatore district (Hora, 1923). It

is common in Periyar, Chaliyar and Kabini River (Easa and Basha, 1995; Arun, 1997).

Anamalai hills, Nilgiri Hills, Cauvery River.

Local name: South Indian sucker catfish

Remarks: This catfish which attains a length of 11.5 cm is of no fishery value.

5. Family CLARIIDAE

Air breathing catfishes

Large sized elongate fishes with a compressed body. Teeth on premaxillaries, mandible

and vomer. Nostrils widely separated, anterior tubular, situated near tip of snout, posterior slit-

like and with nasal barbel. Barbels eight, well developed. Gill openings wide, extending to above

base of pectoral fins. An air-breathing organ arising from the branchial arches ma be present.

Branchiostegal rays 7 to 9.

Rayed dorsal fin very long, separate or continuous with caudal fin without a spine. No

adipose dorsal fin. Paired fins inserted horizontally. Pectoral fins with a strong spine, may be

serrated; in some genera fin vestigial. Anal fin long, not confluent with caudal. Caudal fin

rounded. Lateral line present, complete. Air-bladder reduced, consisting of two thin walled sacs

united by a transverse tube; two lateral chambers covered by incomplete bony capsule.

Habitat: Fres waters

Distribution: Asia and Africa. Vastly represented in Africa.

Number of genera: In India:2

In Kerala: 2 (Clarias, Horaglanis)

Key to genera of Clariidae

1. Eyes absent. Pectoral fins rudimentary. Accessory dendritic apparatus in gill

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cavity not well developed [Lateral line

faint]......................................................................Horaglanis

= Eyes present. Pectoral fins well developed. Accessory dendritic apparatus in gill cavity

well developed (fig. 5) [Lateral line distinct]..........................................................Clarias

1. Genus CLARIAS Scopoli

Clarias Scopoli, 1777, Introductio ad historiam Naturalam: 445 (type-species, Silurus

anguillaris Linnaeus), Teugels & Roberts, 1987, Zool. J. Linn. Soc., 90: 95 (Type-

species designated); Hora, 1936, Rec. Indian Mus., 38(3): 347-350 (Review).

Diagnosis: Body elongated, compressed. Abdomen rounded. Head moderate sized,

greatly depressed, covered with osseous plates dorsally and laterally forming a cask

covering a diverticulum of the gill cavity. Snout broadly rounded or pointed. Mouth

terminal, fairly wide, transverse. Eyes small, dorsolateral with free orbital margins, not

visible from ventral surface. Lips fleshy, papillated. Jaws subequal; upper jaw longer.

Teeth villiform in broad bands or patches on jaws and palate. Four pairs of barbels, one

pair each of maxillary, nasal and two of mandibular. Gill membranes deeply notched,

partly united with each other, free from isthmus. An accessory respiratory dendritic

branchial organ attached to second to fourth branchial arches present (fig. 5).

Rayed dorsal fin long, with 62 to 77 rays and without any spine, commencing

from near occiput and extending to but not continuous with caudal. Adipose dorsal fin

absent. Pectoral fins with 7 to 11 rays and a strongly serrated spine; spine enveloped in

skin. Pelvic fins with 6 rays. Anal fin long with 45 to 63 rays. Caudal fin almost rounded.

Lateral line complete, simple.

Air bladder reduced, consisting of two thin walled sacs united by a transverse

tube; the lateral chambers covered by incomplete bony capsule.

Habitat: fresh waters

Distribution: Africa and South Asia.

Number of species: In India: 4

In Kerala: 2

Key to species

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1. Snout more or less pointed. Nasal barbels much less than half of head length

[Pectoral spine strongly serrated on its outer border].....................................Clarias

dussumieri dayi

1. Snout broad. Nasal barbels not more than two times in head length [Dorsal fin

with 66 to 69 rays. Pectoral spine strongly serrated on its posterior

border]..........................................

............................................................................................ Clarias dussumieri dussumieri

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Species found in Kerala

1. Clarias dussumieri dussumieri Valenciennes

(Plate IV – Fig.12 & Plate V – Fig.13)

Clarias dussumieri Valenciennes, 1840, Hist. nat. Poiss., 15: 382 (type-locality:

Pondicherry; Malabar); Day (partim), 1877, Fishes of India: 484; Day (partim), 1889,

Fauna Br. India, Fishes, 1: 117; Hora, 1941, Rec. Indian Mus., 43(2): 113. fig. 6;

Misra, 1976, Fauna of India, Pisces (2nd ed. ), 3: 130.

Diagnosis: Dorsal fin with 66 to 69 and anal fin with 45 to 59 elements. Maxillary

barbels extend beyond the pectoral fin base. Dark brown on the back and pale below and

flanks.

Habitat: Fresh water, Found in ditches; prefers lower reaches of streams, rivers and canal

with muddy bottom; commonly found in ponds, swamps and paddy fields.

Distribution: Peninsular India (Goa, Kerala, Karnataka and Pondicherry)

Local name: Valenciennes clariid

Remarks: This species is similar to C. dussumieri brachysoma in general appearance but

differ from it in having 1) Dorsal fin with 66 to 69 rays (in C. dussumieri brachysoma

dorsal fin is with 70 to 77 rays) and 2) Pectoral spine strongly serrated on its posterior

border (in C. dussumieri brachysoma pectoral spine is rough externally).

2. Clarias dussumieri dayi Hora

(Plate V – Fig.14)

Clarias dussumieri (nec Valenciennes) day (partim), 1877, Fishes of India : 484 ; Day

(partim), 1889, Fauna Br. India, Fishes, 1: 117.

Clarias dayi Hora, 1936, Rec. Indian Mus., 38 (3) : 350, fig. 4c (type-locality : Wynaad,

Kerala) ; Misra (partim), 1976, Fauna of India, Pisces (2nd ed.), 3: 129.

Clarias dussumieri dayi : Silas, 1952, Proc. Nat. Inst. Sci. India, 18: 435.

Diagnosis: Distance from dorsal fin base of occipital process 2.0 to 3.5 times in head

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length. Snout pointed nasal barbels more than two times in head length.

Habitat: Fresh water, demersal.

Distribution: Wayand Hills, Kerala. So far this specimen is known only from the type

specimen collected by Day in 1877. The only report available after its original description

is by Manimekalan (1998) from Mudumalai Wildlife Sanctuary. Talwar and Jhingran

(1991) treated this species as a separate species where as Jayaram (1981 a) considered it

as a subspecies.

Local name: Malabar clariid

Remarks: This is a very rare species being known only by a single specimen, 17.5 cm in

length collected by Dr. F. Day in 1877.

2. Genus Horaglanis Menon

Horaglanis Menon, 1951, Rec. Indian Mus., 48(1): 60 (type species Horaglanis krishnai

Menon); Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 132-133 (Review).

Diagnosis: Body elongated. Abdomen rounded. Head short, devoid of osseous plates,

globular. Snout truncated. Mouth subvertical, fairly wide, crescentic. Eyes absent. Lips

thick, fleshy. Jaws subequal. Teeth villiform, closely set in broad bands or patches in

jaws and palate. Four pairs of barbels, one pair each of maxillary, nasal and two of

mandibular. Gill membranes united with each other and also with isthmus. Two small

bony structures corresponding to the second and fourth arch represent the dendritic

apparatus.

Rayed dorsal fin long, with 23 rays, commencing in the beginning of the third of

the distance between the tip of snout and caudal fin base, and extending to caudal but free

from it. Adipose dorsal absent. Pectoral fins vestigial, with a central axial ray which bears

six small rays distally and nine smaller rays on the sides. Pelvic fins with 6 rays. Anal fin

long with 17 rays, free from caudal. Caudal fin rounded. Lateral line faint.

Air bladder bag like, laterally broader than long, slightly notched at the anterior

end, completely free.

Habitat: Inhabit in wells

Distribution: India: Kottayam, Kerala state.

Number of species: This genus is represented by a single species Horaglanis krishnai

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Menon and it is known only from Kerala.

1. Horaglanis krishnai Menon

(Fig. 50, Plate V – Fig.15)

Horaglanis krishnai Menon, 1951, Rec. Indian Mus., 48(1): 64, figs 2, 3 & pl. 1, figs1-3

(type-locality: well at Kottayam, Kerala); Misra, 1976, Fauna of India, Pisces (2nd ed.), 3:

132. pl.2, figs 3-4.

Fig. 50

Diagnosis: Body elongated and cylindrical. Head short and tubular. Eyes absent. Barbels

four pairs. Dorsal and anal fin long based. Pectoral fin vestigial.

Habitat: This is restricted to subterranean wells in Kottayam district of Kerala. Migrate

from one well to another through underground water channels.

Distribution: Reported only from Kottayam District of Kerala.

Local name: Indian blind catfish

Remarks: Bones of the skull firmly articulated. Brain teleostean. Absence of eyes

brought about the degeneration of the optic lobes. Skin devoid of scales

6. Family HETEROPNEUSTIDAE

Stinging catfishes; Airsac catfishes

Diagnosis: Moderate sized elongate fishes with a compressed body. Teeth on

premaxillaries, mandible and vomer. Nostrils widely separated, anterior produced into a

short tube, on tip of snout, posterior slit-like behind nasal barbels. Barbels eight, well

developed. Gill openings wide, extending to above base of pectoral fins. A long air-sac

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extends posteriorly from gill chamber through muscles of back to tail (fig.6).

Branchiostegal rays seven.

Rayed dorsal fin short and without any spine. Paired fins inserted horizontally.

Adipose dorsal fin absent or represented by a low ridge. Pectoral fins with a strong spine,

serrated. Anal fin long, just reaching or united with caudal. Caudal fin almost rounded.

Lateral line present, complete.

Habitat: Fresh water

Distribution: India, Bangladesh, Myanmar, Pakistan, Sri Lanka, Thailand and Vietnam.

Absent from Malaya and East Indies.

Number of genus: 1, Genus Heteropneustes Muller

1. Genus Heteropneustes Muller

Heteropneustes Muller, 1840, Arch. Anat. Physio., p.115 (type-species, Silurus fossilis

Bloch, by monotypy).- Hora, 1936, Rec. Indian Mus., 38, pp.208-209 (review).- Jayaram,

1980, Occ. Papers ZSI, No. 23, p.11.

Saccobranchus Valenciennes, 1840, Hist. nat. Poiss., 15, p.399 (type-species,

Silurus singio Hamilton-Buchanan = S. fossilis Bloch).

Diagnosis: Body elongate, compressed. Abdomen rounded. Head moderate sized, greatly

depressed, its dorsal and lateral parts covered with bony plates. Snout flat. Mouth

terminal, transverse, narrow. Eyes small, lateral, in anterior part of head, not visible from

below ventral surface. Lips fleshy, papillated. Jaws subequal. Teeth villiform in broad

bands on jaws and in two oval patches on palate. Four pairs of barbels; one pair each of

maxillary, nasal and two of mandibular. Gill membrane separated by a deep notch, not

united with isthmus.

Rayed dorsal fin short, inserted above tip of pectoral fins with six to eight rays

and without any spine. Adipose dorsal absent or represented by a low adipose ridge,

along posterior third of caudal region. Pectoral fins with seven or eight rays and a strong

spine serrated along inner edge. Pelvic fins with 6 rays. Anal fin long with 60 to 79 rays,

just reaching or confluent with caudal fin. Caudal fin almost rounded. Lateral line

comlete, simple.

Air-bladder greatly reduced, consisting of two thin walled pyriform sacs

enclosed in incomplete bony capsules. Sacs united by a transverse tube which is

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connected with oesophagus through a slender tube.

Habitat: Fresh water

Distribution: Widely distributed in the oriental region. India, Bangladesh, Laos, Nepal,

Pakistan, Sri Lanka and Thailand.

Number of species: In India and in Kerala: 2 species, Heteropneustes fiossilis and H.

microps

Key to species of Genus Heteropneustes found in Kerala

1. Anal fin separated from the caudal fin by a deep notch. Occipital process not

reaching base of dorsal

fin....................................................................................................H. fossilis

= Anal fin confluent with caudal fin. Occipital process reaching base of dorsal

fin.........................................................................................................................H. microps

1. Heteropneustes fossilis (Bloch)

(Figure 51, Plate VI – Figs.16 &17)

Silurus fossilis Bloch, 1794, Naturgesch. Ausl. Fische, 8: 46, pl. 370, fig. 2 (type-locality:

Tranquebar, Tamil Nadu).

Saccobranchus fossilis: Day, 1877, Fishes of India: 486, pl. 114, fig.1: Day, 1889, Fauna

Br. India, Fishes, 1: 125, fig. 53.

Heteropneustes fossilis: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 135, fig. 24.

Fig. 51

Diagnosis: Anal fin separated from the caudal fin by a deep notch. Occipital process not

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reaching base of dorsal fin

Habitat: This species in quite common in the fresh water low lands. Found mainly in

ponds, ditches, swamps and marshes, but sometimes occurs in muddy rivers. Can tolerate

slightly brackish water.

Distribution: India, Pakistan, Nepal, Bangladesh, Sri Lanka, Myanmar, Thailand and

Laos. Also reported from Andaman and Nicobar Islands.

Local name: Stinging cat fish, Scorpion catfish, Kari (Mal.), Kadu (Mal.).

Remarks: It is a fish of high economic importance. This is primarily a fish of ponds,

ditches, swamps and marshes. It is able to tolerate slightly brackish water. Its air

breathing apparatus enables it to exist in almost any kind of water. It attains a length of

30 cm and is in greast demand because of its medicinal value. The fish is much dreaded

because of its aggressive behaviour and can inflict painful wounds with its potentially

dangerous pectoral spines.

2. Heteropneustes microps (Gunther)

(Fig.52)

Saccobranchus microps Gunther, 1864, Cat. Fishes Br. Mus., 5: 31 (type-locality : Sri

Lanka) ; Day, 1877, Fishes of India : 486 ; Day, 1889, Fauna Br. India, Fishes,

1 : 125.

Heteropneustes microps : Misra, 1976, Fauna of India, Pisces (2nd ed.), 3 : 137 ;

Srivastava and Datta Munshi and Srivastava, 1988, Natural History of Fishes and

Systematics of Freshwater Fishes of India : 298, pl. 37, fig. 2.

Fig. 52

Diagnosis: Anal fin confluent with caudal fin. Occipital process reaching base of dorsal

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fin.

Habitat: The air sac catfish has been found in an area heavily modified by man, where it

inhabits swamps and similar still, often turbid waters, such as irrigation ditches. It

inhabits both fresh and brackish waters.

Distribution: North India: Bihar and Uttar Pradesh (Datta Munshi & Srivastava, 1988).

Very rare in Sri Lanka.

Local name: Sri Lanka stinging cat fish, Kari (Mal.), Kadu (Mal.)

Remarks: This species which attains a length of 30 cm is esteemed as food for its

invigorating qualities.

7. Family ARIIDAE

Sea catfishes

Robust large sized, more or less elongate fishes with a compressed body. Teeth on

premaxillaries, mandible, vomer and palatines, may be absent on either of latter two or on

both. Nostrils close together, posterior with a valve, but without a barbel. Barbels two or

six, moderate to well develop (no nasal barbels). Gill openings wide, extending to base of

or above base of pectoral fins. Branchiostegal rays five or six.

Rayed dorsal fin short with a pungent spine. Adipose dorsal fin smooth, not

confluent with either rayed dorsal or with caudal fins. Paired fins inserted horizontally

and plain. Pectoral fins with a sharp, serrated spine. Anal fin moderately long, not

confluent with caudal. Caudal fin forked or bifurcate. Lateral line present, generally

complete.

Air bladder large, with thick walls, in abdominal cavity, not enclosed in bone.

Habitat: Shores, estuaries and seas

Distribution: Subtropical regions

Number of genera: In India: 5 genera

In Kerala: 1 (Arius Valenciennes)

1. Genus Arius Valenciennes

Mouth-breeding catfiahes

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Arius Valenciennes IN: Cuvier &Valenciennes 1840, Hist. Nat. Poiss., 15, p.53 (type-

species, Pimelodus arius Hamilton- Buchanan, by absolute tautonymy).

Tachysurus Lacepede, 1803, Hist. nat. poiss., 5, p.150 (type-species, Tachysurus sinensis

Lacepede, by monotypy).

Chandy, 1954, Rec. Indian Mus., 51 (1), pp. 1-18 (synopsis of species, key).- Jayaram,

1982, Occ. Papers zool. Surv. India, 37, pp. 1-33 (revision).

Diagnosis: Body elongate, compressed. Abdomen rounded. Head large, subconical,

depressed, exposed, with more or less granular or rugose osseous shields on dorsal

surface, or covered with thin skin. Snout conical or pointed obtusely. Mouth subterminal,

moderate or large, transverse. Eyes lateral or slightly directed upwards with free orbital

margin, in middle or anterior part of head, may or may not be visisble from below ventral

surface. Lips thin. Jaws subequal, upper jaw projecting. Teeth villiform, granular or

conical on jaws and palate, in bands or patches. Three pairs of barbels; one pair

maxillary, two mandibular. Gill membranes united, connected with isthmus but with a

free posterior margin.

Rayed dorsal fin inserted above middle or last quarter of pectoral fins with six or

seven rays and a pungent, strong spine. Adipose dorsal short or of moderate length,

posteriorly free. Pectoral fins with nine to twelve rays and a strong serrated spine. Pelvic

fins with six rays. Anal fin short with 14 to 24 rays. Caudal fin forked with rounded or

acute lobes. Lateral line prominent, complete, simple. Air-bladder large, heart shaped,

free, not enclosed in bone.

Habitat and Distribution: Seas and estuaries of tropical regions ascending to within

tidal influence or even entering fresh water

Number of species in India: 11 species are reported from India

In Kerala: 1 species (Arius arius)

1. Arius arius (Hamilton-Buchanan)

(Fig. 53)

Pimelodus arius Hamilton-Buchanan, 1822, Fishes of Ganges: 170, 376 (type-locality:

estuaries of Bengal).

Arius buchanani Day, 1877, Fishes of India: 463, pl. 105, fig. 6 (type-locality: Hoogly

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River at Culcutta; Burma); Day, 1889, Fauna Br. India, Fishes, 1: 181.

Tachysurus arius: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 32, fig. 3.

Arius arius: Jayaram., 1982, rec. zool. Surv. India Occ. Paper, (37): 16, fig. 12.

Fig. 53

Diagnosis: Teeth on palate as a single oval or elongated patch on each side (fig 53);

Pectoral spine shorter or equal to dorsal spine. Palate teeth loosely packed, irregularly

ovate in shape. Anal fin with 20 or 21 rays. Horn-like conical projection of palate teeth

patch present anteriorly. Dorsal fin with a filamentous prolongation.

Habitat: Seas and Estuaries

Distribution: India: Kerala, Orissa, Tamil Nadu and West Bengal. Myanmar.

Local name: Marine catfish, Hamilton's catfish, Theadfin seacatfish

Remarks: This is an estuarine catfish and is common in estuaries, tidal rivers and

brackish water lakes of India. . It attains a length of 20 cm; common as 15 cm standard

length.

8. Family PLOTOSIDAE

(Eel tail catfish)

Large sized elongate fishes with a compressed body and tapering or bluntly

rounded tail. Teeth on premaxillaries, mandible and vomer. Nostrils widely separated,

anterior tubular, in front border of upper lip, posterior slit-like, between eye and upper

lip. Barbels eight, well developed; occasionally labial folds at angle of mouth produced

into short barbels. Gill openings wide, extending to above base of pectoral fins. Gill

membranes free from each other may be totally or partly united with isthmus or free from

it.

Two rayed dorsal fins, first small with a smooth or serrated spine; second very

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long, confluent with procurrent caudal (dorso-caudal fin). No adipose dorsal fin. Pectoral

fins laterally inserted with a strong serrated spine. Pelvics inserted horizontally. Anal fin

many rayed, confluent with caudal fin. A well developed dendritic organ between vent

and anal fin present. Caudal fin pointed. Lateral line conspicuous, represented by distant

pores.

Air-bladder fairly large in proportion to body size, free, not enclosed in bone.

Palatined rod like, 3/5th of autosphenotics provide facet for articulation of

hyomandibular. Endopterygoid absent. Ectopterygiod small, toothless, suturally

articulated to the long, flat, metapterygoid. Metapterygiod suturally connected with

hyomandibular. Post-temporals connected to skull by ligament. Inferior limb of post-

temporals well developed, attached to basioccipital. Mesocoraccoid in shoulder girdle

present.

Habitat: Mainly marine, entering rivers and with some permanently fluviatile species.

Distribution: Indo-Pacific Ocean

Number of genera: Only a single genus – Plotosus

Genus Plotosus Lacepede

Plotosus Lacepede, 1803, Hist. nat. Poiss. , 4, p.129 (type-species, Platystacus

anguillaris Bloch = Silurus lineatus Thunberg); Gomon and Taylor, 1982, J. L. B.

Smith Inst. Icthyol. Sp. Publ., (22): 1-16 (Review).

Diagnosis: body elongate, compressed. Abdomen subcylindrical, tail tapering. Head

moderately depressed, short, covered with thin skin. Snout bluntly rounded. Mouth

transverse, cleft not extending to orbit, slightly overhung by snout. Eyes moderate, in

anterior half or middle of head. Lips thick papillated or with laminated folds, upper lip

prominent. Jaws equal. Teeth pleuriserial, conical on upper jaw, molariform on lower

jaw, molar-like on palate.

Two dorsal fins; first inserted above pectoral fin base, with four to six rays and a

pungent spine, second long, uniformly low, united with caudal. No adipose dorsal fin.

Pectoral fins with 9 to 13 rays and a weak strong serrated spine. Pelvic fins with 10 to 16

rays. Anal fin long, confluent with caudal fin with 58 to 131 rays. A dendritic post-anal

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apparatus close behind anal fin present. Caudal fin bluntly pointed or rounded. Lateral

line complete, conspicuous with distant pores.

Habitat: Marine habitat but visit fresh water.

Distribution: India, Bangladesh, Myanmar, Pakistan, SriLanka, Red sea, Seychelles,

Natal, Mauritius, Malaya, Singapore, Thailand, Indonesia, Amoy, Hong Kong, Japan,

Philippines, British N. Guinea, Australia and Tahiti (Jayaram 1991).

Remarks: These fishes are marine but they visit fresh water.

Number of species: In India: 3

In Kerala: 2 species (Plotosus lineatus, Plotosus canius)

Key to species of Genus Plotosus found in Kerala

1. Body with two or three prominent pale stripes, two extending onto head (stripes often

indistinct in large specimens); nasal barbels short; total rays in confluent median fins 139

to 200……………………………………………………………………..….…P. lineatus

= Body without stripes; nasal barbels long, reaching well behind eyes, usually to nape;

eyes small, the diameter 8.3 to 14.3 times in head length; large vermiform papillae on gill

arches and gill filaments………………………………………………….…….P. canius

1. Plotosus canius Hamilton-Buchanan

(Fig. 54, Plate IX-Fig.24)

Plotossus canius Hamilton-Buchanan, 1822, Fishes of Ganges : 142, 374, pl. 15, fig. 44

(type-locality : rivers of lower bengal) ; Day, 1877, Fishes of India : 482, pl.112,

fig. 3 ; Day, 1889, Fauna Br. India, Fishes, 1 : 113, fig. 47 ; Misra, 1976,Fauna of

India, Pisces (2nd ed.), 3 : 150, fig. 26.

Fig. 54

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Diagnosis: Body plain without any stripes; Nasal barbels extending considerably beyond

eyes. Colour generally olive-green without any stripes on body. Eye diameter 8.3 to 14.3

times in head length.

Habitat: Marine, Found mostly in estuaries and lagoons, and sometimes up rivers in

nearly fresh waters. Occurs in the lower parts of rivers in freshwater or brackish water

and in coastal seas

Distribution: India: Andaman Islands, Kerala, Maharashtra, West Bengal, Bangladesh,

Malaya, Myanmar, Pakistan and Sri Lanka.

Local name: Canine catfish-eel, Black-tip catfish

Remarks: This catfish contributes a moderate fishery in the Hooghly estuary (West

Bengal) and also in other brackish water lakes along the east coast of India. It attains a

length of 150 cm; common to 80 cm. The flesh is readily marketable. It is a suitable

species for brackish water fish culture in India.

2. Plotosus lineatus (Thunberg)

(Fig. 55, Plate IX-Fig.25)

Silurus lineatus Thunberg, 1787, K. Vetensk. Akad. Nya Handl., 12: 190 (type-locality:

Indian Ocean).

Plotosus arab (Bleeker) Day, 1877, Fishes of India: 483, pl. 112, fig. 4; Day,1889, Fauna

Br. India, Fishes, 1: 113; Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 148.

Plotosus anguillaris (Bloch) Misra, 1962, Rec. Indian Mus., 57: 117.

Fig. 55

Diagnosis: Body with two or three prominent pale stripes. Two dorsal fins; first inserted

above pectoral fin base, with four to six rays and a pungent spine, second long, uniformly

low, united with caudal. No adipose dorsal fin. Pectoral fins with 9 to 13 rays and a weak

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strong serrated spine. Pelvic fins with 10 to 16 rays. Anal fin long, confluent with caudal

fin with 58 to 131 rays. A dendritic post-anal apparatus close behind anal fin present.

Caudal fin bluntly pointed or rounded.

Habitat: Marine and fresh water, the only catfish found in coral reefs. Also found in

estuaries, tide pools and open coasts.

Distribution: India: Kerala, Gujarat, Maharashtra, Tamil nadu. Pakistan: Makran,

Myanmar, Sri Lanka.

Local name: Striped eel-catfish, Coral catfish

Remarks: This is a marine catfish which penetrates brackish and fresh waters. It attains a

length of 30 cm and important in fishery industry.

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DISCUSSION

Kerala exhibit high variability in fish assemblages. Highest diversity of species is

reported in this region. Many of the catfishes reported from Kerala are endemic to this

region. Batasio travancoria is the only species reported from the genus Batasio.

Horabagrus brachysoma is highly abundant where as Horabagrus nigricollaris is a

recently described species. Highest number of species is reported from the Genus Mystus,

8 species. The Genus Silurus include a species known only from South India, Silurus

wynaadensis. The family Schilbeidae includes two subfamilies but only the subfamily

Schilbeinae include members reported from Kerala. This subfamily has three genera

with single species each seen in Kerala. The species are Psedeutropius mitchelli,

Proeutropiichthys takree takree and Silonia Childreni. Family Sisoridae consist of 1

genus with 5 species. They are the category of sucker catfishes. The members of the

family Clariidae are highly endemic to Kerala. Their number is found to decrease year by

year and they have reached a stage of extinction. Horaglanis krishanai Menon is a

species so far reported only from the wells of Kottayam district of Kerala. The family

Heteropneustidae includes the stinging catfishes. The family Ariidae and Plotosidae

include the fishes that are seen marine habitat, entirely different from the other members

of this order. These fishes but visit freshwater at regular intervals.

Some members of the genus bear very close similarity to each other so that

identification is difficult. Such resemblances and differences of related species important

to taxonomy are discussed below in detail.

Batasio travancoria shows similarity to Batsio batasio in general appearance but

differ from it in having 1) Body without longitudinal bands or spots (Body marked with

longitudinal bands in B.batasio, 2) Occipital process not reaching basal bone of dorsal

fin, separated by a considerable distance (Occipital process extends to the basal bone of

dorsal fin in B. batasio) and 3) Pores on dorsal surface of head present (in B. batasio, no

pores on dirsal surface of head).

Horabagrus brachysoma comes very near Horabagrus nigricollaris in general

appearance but differs from it in having 1) a black ocellus at the humeral region (in H.

nigricollaris no such ocellus occurs but a saddle shaped band over the nape).

Horabagrus nigricollaris is a recently described species from Chalakudy River at

Vettilappara. This species come very near Horabagrus brachysoma in general

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appearance but differs from it in having 1) A saddle shaped band over the nape (such a

band is absent in H. Brachysoma); 2) No ocellus at the humeral region (A black ocellus

present at the humeral region in H. brachysoma).

Mystus armatus is morphologically very much similar to Mystus castaneus in

general appearance but differ from it in having a thin, dark band running along the length

of the body (Mystus castaneus does not possess such dark band).

Mystus keletius is morphologically similar to Mystus malabaricus in general

appearance but differ from it in having 1) Body depth 4 times in standard length (Body

depth 4.5 to 6 times in standard length in M. malabaricus, 2) A light band above and

below lateral line (A dark band only along the lateral line ending with a dark blotch at

base of caudal fin in M.malabaricus) and 3) maxillary barbel extend to the middle of

pelvic fin (maxillary barbel extend to the end of pelvic fin in M. malabaricus).

Mystus montanus resembles Mystus vittatus in general appearance but differ from

it in having 1) Eye-diameter 3.5 to 4 times in head length (in M. vittatus , eye diameter

4.5 to 6 times in head length, 2) Pectoral fin with 6 rays (in M. vittatus pectoral fin with

9 soft rays and 3) body marked with one or two longitudinal light bands above lateral line

(in M. vittatus body marked with 3 or 4 longitudinal pale blue or dark brown or black

bands above and below lateral line).

Mystus cavasius resembles Mystus pulcher in general appearance and also in the

presence of a dark spot on base of caudal fin but differ from it in having 1) Median

longitudinal groove on head extends to base of occipital process (in Mystus pulcher

median longitudinal groove on head not extends to base of occipital process).

Ompok malabaricus is similar in appearance to Ompok bimaculatus in outer

appearance but differ from it in having anal fin with 63 to 69 branched rays (In O.

bimaculatus anal fin is with 57 or 58 branched rays.

Pseudeutropius mitchelli is similar to P. atherinoides in general appearance , but

differ from it in having 1) Eye diameter 3.0 to 3.5 in head length (In P. atherinoides eye

diameter 2.5-3.0 times in head length) 2) Nape slightly elevated (In P. atherinoides nape

well elevated) and 3) Teeth on palate in two small oval patches (In P. atherinoides teeth

on palate in two narrow separate cresecentic patches).

Proeutropiichthys taakree taakree is similar to P. takree macrophthalmos in

general appearance but differ from it in having 1) Interoperculum with two prominent

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spurs separated by a notch ( in P. takree macrophthalmos interoperculum is rounded

without any spurs), 2) Eye diameter 2.75 to 3.0 times in head length (in P. takree

macrophthalmos eye diameter is 3.5 to 3.6 times in head length and 3) Maxillary barbels

extend to pelvic fins (in P. takree macrophthalmos the maxillary barbel extend only upto

tip of pectoral fins).

Silonia childreni is similar to Silonia silondia in general appearance but differs

from it in having 1) Large air bladder (In S. silondia air bladder is greatly reduced), 2)

Maxillary barbel long, extending to operculum (In S. silondia maxillary barbels minute,

not extending beyond orbit) and 3) mandibular barbels equal to diameter of eyes (In S.

silondia mandibular barbels vestigial).

G. lonah resemble G. madraspatanum in general appearance but differ from it in

having 1) Paired fin plaited (Paired fins not plaited in G. madraspatanum), 2) Skin

granulated (Skin smooth or occasionally tuberculated in G. madraspatanum) and Rayed

dorsal fin height 1/4depth of body (Rayed dorsal fin height 1.0 to 1.3 times depth of body

in G. madraspatanum).

Clarias dussumieri dussumieri is similar to C. dussumieri brachysoma in general

appearance but differ from it in having 1) Dorsal fin with 66 to 69 rays (in C. dussumieri

brachysoma dorsal fin is with 70 to 77 rays) and 2) Pectoral spine strongly serrated on its

posterior border (in C. dussumieri brachysoma pectoral spine is rough externally).

Heteropneustes fossilis is similar to H. microps in general appearance but differs

from it in having 1) Anal fin separated from the caudal fin by a deep notch (in H. microps

anal fin confluent with caudal fin) and 2) Occipital process not reaching base of dorsal fin

( In H. microps occipital process reaching base of dorsal fin).

Heteropneustes microps is similar to H. fossilis in general appearance but differ

from it in having 1) anal fin confluent with caudal fin (In H. fossilis anal fin separated

from the caudal fin by a deep notch) and 2) occipital process reaching base of dorsal fin

(In H. fossilis occipital process not reaching base of dorsal fin.

Arius arius is similar to A. gagora in general appearance but differs from it in

having 1) Anal fin with 20 or 21 rays (in A. gagora, anal fin with 18 or 19 rays), 2) Horn-

like conical projection of palate teeth patch present anteriorly (in A. gagora, horn like

conical projection of palate teeth patch present posteriorly) and 3) Dorsal fin with a

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filamentous filamentous prolongation (in A. gagora dorsal fin without a filamentous

prolongation).

Plotosus canius is similar in appearance to P. limbatus but differ from it in having

1) Nasal barbels extending considerably beyond eyes (in P. limbatus nasal barbels not

extend farther than hind border of eyes) and 2) Eye diameter 8.3 to 14.3 times in head

length (in P. limbatus eye diameter 5 to 9 times in head length).

Plotosus lineatus bear similarity with P. canius in general appearance but differ

from it in having three prominent pale stripes on the body (in P. canius body is plain

without any stripes).

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SUMMARY

The contribution made by scientists all over the world on the systematics of the

Order Siluriformes was briefly reviewed in this small work with special reference to the

Catfishes seen in Kerala. The live samples caught from the river using various fishing

nets and the dead samples collected from the markets were transported to the laboratory

for further analysis. Using standard taxonomical textbooks the samples were identified

and the species was described. A dichotoumous key was prepared for the Family, Genera

and species found in Kerala. An analysis on the resemblances and differences of related

species were discussed.

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CONCLUSION

The study was conducted to review the catfishes found in Kerala. From the study

it was found that Kerala catfishes belong to 8 families, 15 gnera and 31 species. Majority

of the fishes are highly endemic to Kerala seen only in specific geographic regions. Some

of the fishes are at the verge of extinction, like Clarias dussumieri dussumieri where as

some of them are known only by the description like Clarias dussumieri dayi. A

scientific approach is needed to protect these economically important food and aquarium

fishes to protect from extinction. Also a detailed taxonomic study should be conducted in

this area of Kerala catfishes to avoid the confusion in scientific identification.

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BIBLIOGRAPHY

Ajithkumar, C. R., Remadevi, K., Thomas, K. R., and Biju, C. R. 1999. Fish fauna,

abundance and distribution in Chalakudy river system, Kerala. Journal of the

Bombay natural History Society 96(2): 244–254

Arun, L. K. 1997. Patterns and processes of fish assemblages in Periyar lake- Valley

system. KFRI Research Report (Draft).

Arun, L. K., C. P. Shaji and P. S. Easa 1996. Record of new fishes from Periyar Tiger

Reserve. Jornal of the Bombay natural History Society 93 (1): 102.

Balogun, J. K. 2005. Fish Distribution in a small Domestic Water Supply Reservoir: A

Case Study of Kangimi Reservoir, Kaduna, Nigeria, 9(1): 93-97.

Breder, C. M. and D.E. Rosen 1966. Modes of reproduction in fishes. T.F.H.

Publications, Neptune City, New Jersey. 941 p.

Bruton, Michael N. 1996. "Alternative life-history strategies of catfishes" Aquatic Living

Resources. 9: 35–41.

Datta Munshi, J. S., Srivastava, M.S. 1988. Natural History of fishes and systematic of

freshwater fishes in India. Narendra Publishing Co. Delhi, India. 421 pp.

Day, F. 1875-78. The fishes of India: being a natural history of the fishes known to

inhabit the seas and fresh waters of India, Burma and Ceylon. Text and Atlas in 4

parts. London, xx + 778 pp., 195 pls. e

Easa P.S. and C. P. Shaji 1997. Freshwater fish diversity in Keralapart of the Nilgiri

Biosphere reserve. Current Science 73(2): 180-182.

Ferraris, Carl J., Jr. 2007. "Checklist of catfishes, recent and fossil (Osteichthyes:

Siluriformes), and catalogue of siluriform primary types". Zootaxa 1418: 1–628.

Ferraris, Carl J., Jr.; Reis, Roberto E. 2005. "Neotropical catfish diversity: an historical

perspective". Neotropical Ichthyology 3 (4): 453–454.

Froese, Rainer, and Daniel Pauly, eds. 2007. " Horabagrus nigricollaris " in FishBase.

May 2007 version.

Froese, Rainer, and Daniel Pauly, eds. 2007. "Parakysidae" in FishBase. Apr 2007

version.

Gopi, K. C. and Radhakrishnan, C. 1998. Freshwater fish diversity in Wayanad, Kerala,

South India- A revised check list. Zoo’s Print. XIII 12: 31.

Hendrickson, Dean A. Krejca, Jean K. Martinez, Juan Manuel Rodríguez 2001. "Mexican

94

94

blindcats genus Prietella (Siluriformes: Ictaluridae): an overview of recent

explorations". Environmental Biology of Fishes 62: 315–337.

Hora, S. L. 1921a. Fish and fisheries of Manipur with some observations on those of the

Naga Hills. Records of the Indian Museum., 22(3): 165-214.

Hora, S. L. 1938. The game fishes of India, IV. The Silond catfish Silonia silonddia

(Hamilton). Jornal of the Bombay natural History Society., 40(2): 137-147.

Hora, S.L. & Law, N.C. 1941. The fresh water fish of Travancore. Records of the Indian

Museum., 43 (2): 233-256.

Jayaram, K.C., 1981, The freshwater fishes of India, Pakistan, Bangladesh, Burma and

Sri Lanka - a handbook., Zoological Survey of India, Calcutta. 475 p.

Jayaram, K.C., 1999, The freshwater fishes of the Indian region., Narendra Publishing

House, Delhi - 110006, India. 551 p.

Jenny Baker, 1988, Simply Fish p 36-37. Faver & Faber, London

Johal, M. S., Tandon, K. K. 1979. "Monograph on the fishes of the reorganized Punjab.

Part I" Punjab Fisheries Bulletin 3: 1-44.

Jayaram, K. C. 1977. Aid to identification of siluroid fishes of India, Burma, Sri Lanka,

Pakistan and Bangladesh. I. Bagridae. Records of the Zoological Survey of India

Occasional Paper, (8): 1-41.

Jayaram, K.C. and Anuradha Sanyal, A. 2003. Taxonomic Revision of the Fishes of the

Genus Mystus Scopoli (Family Bagridae), Zoological Survey of India, pbk, iv, 136

p, figs, tables, 5 plates.

Langecker, Thomas G.; Longley, Glenn. 1993. "Morphological Adaptations of the Texas

Blind Catfishes Trogloglanis pattersoni and Satan eurystomus (Siluriformes:

Ictaluridae) to Their Underground Environment". Copeia 4: 976–986.

Linder, R. Shane March 2000. "The Catfishes of Asia Family Bagridae part one" . Cat

Chat 1 (1).

Manimekalan, A.1998. The fishes of Mudumalai Wildlife Sanctuary, Tamil Nadu, South

India. Journal of the Bombay natural History Society 95: 431-443.

Menon, A.G.K. 1999. Check list - fresh water fishes of India. Records of Zoological

Survey of India, Miscellaneous Publication Occasional Paper No. 175, 366 p.

Misra, K. S. 1976 b. The Fauna of India and the adjascent countries. Pisces (Second

95

95

edition). 3. Teleostomi: Cypriniformes, Siluri. Delhi. xxi + 387 pp.

Misra, K.S. 1976. Teleostomi: Cypriniformes; Siluri. In: The Director, Zoological Survey

of India (ed.) Thefauna of India and the adjacent countries, Pisces (2nd edition)

Vol. III. The Controller of Publications,Delhi, xxi + 367 pp.

Monks, 2006 Monks N. (editor): Brackish Water Fishes, TFH.

Narendran, T. C. 2000. Importance of Systematics. Resonance, 5: 60-68.

Nelson, Joseph S. 2006. Fishes of the world. John Wiley & Sons, Inc.

Ng, Heok Hee; Sparks, John S. 2005. "Revision of the endemic Malagasy catfish family

Anchariidae (Teleostei: Siluriformes), with descriptions of a new genus and three

new species". Ichthyological Exploration of Freshwaters 16 (4): 303–323.

Pethiyagoda, R. 1991. Freshwater fishes of Sri Lanka. The Wildlife Heritage Trust of Sri

Lanka, Colombo. 362 p.

Pethiyagoda, R. & Kottelat, M. 1994. Three new species of fishes of the genera

Osteochilichthys (Cyprinidae), Travancoria (Balitoridae) and Horabagrus

(Bagridae) from the Chalakudy River, Kerala, India. Journal of the South Asian

natural History Volume 1 . Number 1.

Remadevi, K. and Indra. 1986. Fishes of Silent Valley. Records of the Zoolical Survey of

India. 84: 243-257.

Roberts, T. R., 1994. Systematic revision of Asian bagrid catfishes of the genus Mystus

sensu stricto, with a new species from Thailand and Cambodia. Ichthyological

Exploration of Freshwaters v. 5 (3): 241-256.

Rogers, Paul. "Economy of Scales". Stanford Magazine. Stanford Alumni Association.

Schäfer F: Brackish Water Fishes, Aqualog 2005.

Shaji, C.P., Easa, P.S. and Basha, S.C. 1995. Freshwater fish diversity in Aralam Wildlife

Sanctuary, Kerala, South India. Journal of the Bombay natural History Society.

92(3): 360-363.

Shaji, C. P. and P. S. Easa 1999. A review of the amphibian fauna of Kerala. Zoos Print

Journal. 14(5): 33-35.

Shaji, C.P., P.S. Easa and A. Gopalakrishnan 2000. Freshwater fish diversity of Western

Ghats. p. 33-35. In: Ponniah, A.G. and A. Gopalakrishnan. (eds.). Endemic Fish

Diversity of Western Ghats. NBFGR-NATP Publication. National Bureau of Fish

Genetic resources

96

96

Shaji, C.P. & Easa, P.S. 2001. Field Guide: Freshwater fishes of the Western Ghats.

Kerala Forest Research Institute (KFRI) & National Bureau of Fish Genetic

Resources (NBFGR), 109 pp.

Silas, E. G. 1951. On a collection of fishes from Anamalai and Nelliyampathy hill ranges

(Western Ghats) with notes on its Zoogeographical significances Jornal of the

Bombay natural History Society 49: 670-681.

Silas, E. G. 1952 b. Notes on the fishes of the genus Glyptothorax Blyth from Peninsular

India with description of a new species. Jornal of the Bombay natural History

Society. 50: 323-330.

Simpson, G. G. 1961. Principles of Animal Taxonomy. Columbia University Press, New

York.

Sullivan, J. P., Lundberg, J. G., and Hardman, M. 2006. "A phylogenetic analysis of the

major groups of catfishes (Teleostei: Siluriformes) using rag1 and rag2 nuclear gene

sequences". Molecular Phylogenetics and Evolution 41 (3): 636–62.

Talwar, P.K. and Jhingran, A. G. 1991 Inland fishes of India and adjacent countries.

Volume 2. A.A. Balkema, Rotterdam.

Teugels, G. G. 1995. Taxonomy, phylogeny and biogeography ofcatfishes

(Ostariophysei, Siluroidei): An Overview: Aquatic Living Resources 9: 9-34.

Vitamin D and Healthy Bones". New York State Department of Health.

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PLATE I

Fig. 1 Batasio travancoria(Courtesy to Planetcatfish.com)

Fig.2 Horabagrus brachysoma

Fig.3 Horabagrus nigricollaris(Courtesy to Planetcatfish.com)

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PLATE II

Fig.4 Mystus armatus

Fig.5 Mystus keletius(Picture by Jayasinghe A.)

Fig.6 Mystus montanus

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(Courtesy to Scotcat.com)

PLATE III

Fig.7 Ompok bimaculatus(Courtesy to Scotcat.com)

Fig.8 Ompok malabaricus(Photo by Manimekalan A.)

Fig.9 Silurus wynaadensis100

100

(Picture by Day, 1877)

PLATE IV

Fig. 10 Glyptothorax housei(Photo by Manimekalan A.)

Fig. 11 Glyptothorax lonah(Picture by Day, 1877)

Fig. 12 Clarias dussumieri dussumieri

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PLATE V

Fig. 13 Head of Clarias dussumieri dussumieri

Fig. 14 Clarias dussumieri dayi

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Fig. 15 Horaglanis krishnai (Photo by K. Subhash Babu)

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PLATE VI

Fig. 16 Heteropneustes fossilis

Fig. 17 Heteropneustes fossilis

Fig. 18 Mystus malabaricus(Courtesy to Planetcatfish.com)

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PLATE VII

Fig. 19 Mystus oculatus(Courtesy to kerala-nadu.blogspot.com)

Fig. 20 Mystus vittatus(Courtesy to Scotcat.com)

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Fig. 21 Glyptothorax annandalei(Courtesy to Planetcatfish.com)

PLATE VIII

Fig. 22 Adhesive apparatus of G. annandalei(Courtesy to Planetcatfish.com)

Fig. 23 Mystus cavasius(Photo by Khan M. M.)

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PLATE IX

Fig.24 Plotosus canius

(Courtesy to flickr.com)

Fig. 25 Plotosus lineatus

(Courtesy to encyclopedia of life)

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107