““Freshwater seed shrimps (Ostracoda: Freshwater seed shrimps (Ostracoda: Podocopida) from lakes of Sindh, Pakistan”Podocopida) from lakes of Sindh, Pakistan”

Mukhtiar Ahmed MaharMukhtiar Ahmed MaharMukhtiar Ahmed MaharMukhtiar Ahmed Mahar

Department of Fresh Water Biology and Fisheries,Department of Fresh Water Biology and Fisheries,University of Sindh, Jamshoro, Sindh, Pakistan.University of Sindh, Jamshoro, Sindh, Pakistan.

IntroductionIntroductionOstracodes are referred as “seed Shrimps” because due to their Ostracodes are referred as “seed Shrimps” because due to their

shape and small size, they look like small seeds.shape and small size, they look like small seeds. The body is enclosed in a bivalve, calcified shell (carapace).The body is enclosed in a bivalve, calcified shell (carapace). They are found in marine, brackish and freshwaters. They are found in marine, brackish and freshwaters.

Order Ostracoda is divided into three suborders (i) Myodocopida Order Ostracoda is divided into three suborders (i) Myodocopida (ii) Platycopida and (iii) Podocopida. First two suborders are (ii) Platycopida and (iii) Podocopida. First two suborders are represented in marine and members of the third are found in represented in marine and members of the third are found in freshwater (Pennak, 2001). About 5000 species of Ostracodes freshwater (Pennak, 2001). About 5000 species of Ostracodes are known from various habitats (Oliver are known from various habitats (Oliver et al.et al., 2000)., 2000).

They play important role in aquatic ecosystem as source of They play important role in aquatic ecosystem as source of

natural food for benthivorous fish. natural food for benthivorous fish.

As there is paucity of data on Ostracodes of Pakistan, present As there is paucity of data on Ostracodes of Pakistan, present study was initiated to supply baseline information for future study was initiated to supply baseline information for future research.research.

MATERIALS AND METHODSMATERIALS AND METHODS

Three lakes of Sindh, Keenjhar (Distt: Thatta), Manchhar (Distt: Three lakes of Sindh, Keenjhar (Distt: Thatta), Manchhar (Distt: Dadu) and Chotiari (Distt: Sanghar) were surveyed for the Dadu) and Chotiari (Distt: Sanghar) were surveyed for the collection of seed shrimps during 2008-09.collection of seed shrimps during 2008-09.

Random sampling was carried-out by using No. 25 plankton net Random sampling was carried-out by using No. 25 plankton net (mesh size 55µm). (mesh size 55µm).

Some specimens were also collected from algal mates in shallow, Some specimens were also collected from algal mates in shallow, weedy marginal areas.weedy marginal areas.

The samples were preserved in 5% formalin solution for studies in The samples were preserved in 5% formalin solution for studies in

the laboratory. the laboratory.

Identification was carried with the help of taxonomic keys (Ward Identification was carried with the help of taxonomic keys (Ward and Whipple, 1976, Bronshtein, 1988 and Pennak, 2001). and Whipple, 1976, Bronshtein, 1988 and Pennak, 2001).

Photographs were taken with a digital camera DCM 35 (350 K Photographs were taken with a digital camera DCM 35 (350 K Pixels, USB 1.0, mounted on the trinocular microscope (Nikon, Pixels, USB 1.0, mounted on the trinocular microscope (Nikon, Eclips E-200 and Swift 300-D).Eclips E-200 and Swift 300-D).

ResultsResults

Five genera and species of seed Five genera and species of seed shrimps recorded from Pakistan in shrimps recorded from Pakistan in the present study. the present study.

Table 1. List of Ostracodes reported from PakistanTable 1. List of Ostracodes reported from Pakistan

Gurney (1920) (Nushki, Baluchistan)Gurney (1920) (Nushki, Baluchistan) Cyprinotus incongruensCyprinotus incongruens Ilyocypris bradyiIlyocypris bradyi (Sars, 1890) (Sars, 1890) Eucypris puberaEucypris pubera (Yooung) (Yooung) Cypridopsis dentomarginatusCypridopsis dentomarginatus (Dady) (Dady) Limnicythere inopinitaLimnicythere inopinita (Baraid) (Baraid) Ptamocypris villosaPtamocypris villosa (Jurine) (Jurine)Arora (1931) (Lahore, Punjab)Arora (1931) (Lahore, Punjab) Ilyocypris bradyiIlyocypris bradyi (Sars, 1890) (Sars, 1890) Cypris reticulateCypris reticulate (Zaddach, 1844) (Zaddach, 1844) Cyprinotus crenaCyprinotus crena (Turner, 1893) (Turner, 1893) C. chandraiC. chandrai (Arora, 1931) (Arora, 1931) C. incongruensC. incongruens (Ramdoler , 1808) (Ramdoler , 1808) Eucyprus mathaiEucyprus mathai (Arora, 1931) (Arora, 1931) E. kumariE. kumari (Arora, 1931) (Arora, 1931) Stenocypris malcomcomsoniStenocypris malcomcomsoni (Brady, 1886) (Brady, 1886) Cypretta globulusCypretta globulus (Sars, 1889) (Sars, 1889) Cypria devaiCypria devai (Arora, 1931) (Arora, 1931)Mahoon and Sultana (1977) (Lahore, Mahoon and Sultana (1977) (Lahore,

Punjab)Punjab) Stenocypris fontinalesStenocypris fontinales (Vaura, 1891) (Vaura, 1891)Arora (1935) (Karachi, Sindh)Arora (1935) (Karachi, Sindh) Cypria medianaCypria mediana Cyclocypris globosaCyclocypris globosa Stenocypris malcomsoniStenocypris malcomsoni (Brady, 1886) (Brady, 1886) Cypretta nigra Cypretta nigra Cyprinotus madyensisCyprinotus madyensis Cyprinotus fretensCyprinotus fretens

Present Study (Lower Sindh)Present Study (Lower Sindh)

Cypris subglobosaCypris subglobosa (Sowerby.1840) (Sowerby.1840) Eucypris virensEucypris virens (Jurine, 1820) (Jurine, 1820) Dolerocypris sinensisDolerocypris sinensis (Sars, 1903) (Sars, 1903) Herpetocypris fontinalisHerpetocypris fontinalis (Bronshtein, 1928) (Bronshtein, 1928) Cypridopsis obesaCypridopsis obesa (Brady and Robertson, (Brady and Robertson,

1870)1870)

Cypris subglobosaCypris subglobosa (Sowerby, 1840) (Sowerby, 1840)Shell some what globular in dorsal view, Shell some what globular in dorsal view,

length 1.19 mm,length 1.19 mm, height 0.7mm, height 0.7mm,

width 0.62mm,width 0.62mm,

Eucypris virensEucypris virens (Jurine, 1820) (Jurine, 1820)

Shell somewhat Shell somewhat bean shaped.bean shaped.

Length 1.97mm Length 1.97mm and height 1.06mm and height 1.06mm ..

Dolerocypris simensisDolerocypris simensis (Sars, 1903) (Sars, 1903)

Shell elongated, slightly Shell elongated, slightly convex dorsally, ventral convex dorsally, ventral margin straight.margin straight.

Length 2.02mm, width Length 2.02mm, width 0.72mm. Anterior margin 0.72mm. Anterior margin more rounded then more rounded then posterior.posterior.

Anterior margin bears Anterior margin bears marginal bristles. marginal bristles.

Shell fairly transparent, Shell fairly transparent, yellowish brown in colour, yellowish brown in colour, a yellowish green spot a yellowish green spot extends across the shell. extends across the shell. Six, elongated muscle Six, elongated muscle attachment scars visible in attachment scars visible in the centre of shell the centre of shell

Herpetocyperis fontinalisHerpetocyperis fontinalis (Bronshtein, 1928) (Bronshtein, 1928)

Shell elongated, surface Shell elongated, surface covered with small covered with small setae.setae.

Length 1.49 mm, width Length 1.49 mm, width 0.49 mm and height 0.49 mm and height 0.54 mm.0.54 mm.

Anterior portion of shell Anterior portion of shell broadly rounded, while broadly rounded, while posterior portion posterior portion distinctly narrow. distinctly narrow.

Cypridopsis obesa Cypridopsis obesa (Brady and Robertson, 1877)(Brady and Robertson, 1877)

Shell roughly sub-globular, Shell roughly sub-globular, anterior side broadly anterior side broadly rounded while posterior rounded while posterior end truncated.end truncated.

Length 0.67 mm, width 0.4 Length 0.67 mm, width 0.4

mm and height 0.34 mm.mm and height 0.34 mm.

ConclusionConclusion Gurney (1920) reported six species from western Gurney (1920) reported six species from western

Balochistan, while Arora (1931, 1935) recorded Balochistan, while Arora (1931, 1935) recorded 10 species from Lahore city and 6 species from 10 species from Lahore city and 6 species from Karachi area respectively. Later on, one specie Karachi area respectively. Later on, one specie StenocyprisStenocypris fontinalis fontinalis was reported from Lahore was reported from Lahore area (Mahoon and Sultana, 1977; Chowdhry area (Mahoon and Sultana, 1977; Chowdhry et et alal., 1986). As two species are common from Sindh ., 1986). As two species are common from Sindh and Balochistan, in all 21 species have already and Balochistan, in all 21 species have already been reported from Pakistan the present new been reported from Pakistan the present new record of 5 species from Pakistan (Lower Sindh) is record of 5 species from Pakistan (Lower Sindh) is an addition to already known freshwater Ostracod an addition to already known freshwater Ostracod fauna of Pakistan.fauna of Pakistan.

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