Post on 11-Apr-2015
Dr. PARVISH PANDYA’s presentation
“Porifera : Spicules+ Canal System”A presentation compiled from various sources by
Dr. PARVISH PANDYA,Zoology Dept. Bhavan’s College, Andheri.
Dr. PARVISH PANDYA’s presentation
Sites from which presentations have been downloaded and later editted. I am indeed thankful to them for their kindness and support :http://esg-www.mit.edu:8001/esgbio/cb/org/organelles.htmlhttp://faculty.pnc.edu/jcamp/parasit/parasit.htmlhttp://www.amnh.org/rose/hope/creatinghope/http://www.biology.eku.edu/SCHUSTER/bio%20141/POWERPOINT%20NOTES/Intro%20to%20Protozoa_files/fullscreen.htmhttp://www.biosci.ohio-state.edu/~zoology/eeob405/http://www.tulane.edu/~wiser/protozoology/pwpt/http://www.iep.water.ca.gov/suisun/photos/wildlife.htmlhttp://www.uta.edu/biology/marshall/2343/http://www.uta.edu/biology/faculty/faculty.htmlhttp://www.okc.cc.ok.us/biologylabs/Documents/Zoology/PowerPoint.htmhttp://bio.fsu.edu/http://www.aw-bc.com/http://www.nhm.org/http://www.geo.cornell.edu/eas/education/course/descr/EAS302/presentations/
It is very easy to find mistakes in these presentations…..I request you to kindly rectify them and supply me the modifications needed at parvishpandya@yahoo.comThanks a lot and have fun in teaching & learning Zoology….
Dr. PARVISH PANDYA’s presentation
PHYLUMPORIFERA
Dr. PARVISH PANDYA’s presentation
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Simple Sponge Morphology
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Phylum Porifera - Sponges
• Mostly marine, but include some freshwater inhabitants; usually found attached to the substratum in shallow or deep water.• They are sessile; permanently attached to the substrate• Obtain their food by filter feeding
Dr. PARVISH PANDYA’s presentation
General Morphology
• The internal cavity is called the atrium or spongocoel• Water is drawn into it through a series of incurrent pores or dermal ostia present in the body wall into a central cavity and then flows out of the sponge through a large opening at the top called the osculum
Dr. PARVISH PANDYA’s presentation
Dr. PARVISH PANDYA’s presentation
Spicule
• Skeleton of sponge– Calcium carbonate– Silicon– Collagen
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The SkeletonIn the mesohyl is the skeleton composed of tiny pointed structures made of silica or calcium carbonate called spicules.These structures act as an internal scaffolding, but also function in protectionAmong some sponges the skeleton consist of spongin fibers made of collagenous material; found in many of the commercial sponges
Dr. PARVISH PANDYA’s presentation
Archeocyte
• Amoeboid cells• Receive food from
choanocytes• Differentiate into other
cell types
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Sclerocyte
• Produce spicules
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Asconoid SpongeAsconoid Sponge
OstiumOstiumOstium
SpongocoelSpongocoelSpongocoel
OsculumOsculumOsculum
PorocytePorocytePorocyte
Dr. PARVISH PANDYA’s presentation
Phylum Porifera- Asconoid Type Sponge:
This simplest sponge type has it’s choanocytes located in it’sspongocoel. Note buds (asexual reproduction) and many oscula (pluralof osculum) on this slide. [fig 1.3-A]
Dr. PARVISH PANDYA’s presentation
Phylum Porifera-Asconoid Type Sponge: note spicules, spongocoel, osculum & bud [fig 1.3-A]
Dr. PARVISH PANDYA’s presentation
Phylum Porifera- Asconoid Type Sponge:This simplest sponge type has it’s choanocytes located in it’s
spongocoel. Its also a small sponge type. [fig 1.3-A]
Dr. PARVISH PANDYA’s presentation
Types of Sponges (Canal Systems)
A. Asconoid Sponges
• Simple vase-like structure• This structure puts limitations on size; (increase in volume without a corresponding increase in the surface area of the choanocytes)
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Syconoid Sponge
Osculum
SpongocoelIncurrent Canal
Radial CanalOstium
Choanocytes
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Syconoid SpongeScypha (Grantia) xs
Ostium
Incurrent Canal
Spongocoel
ChoanocytesRadial Canal
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Phylum Porifera- Syconoid Type Sponge:
An example of a syconoid-type sponge.This sponge type has it’s choanocyteslocated in its radial canals. Note the prominent spicules [fig 1.4]
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Types of Sponges (Canal Systems) cont.
B. Synconoid Sponges
• The flagellated choanocytelayer has undergone folding forming finger like projections• There is a single osculum but the body wall is more complex, with water being received through incurrent canals, which pass it along to radial canals through to the spongocoel• Results in an increase in the surface area which allowed sponges to increase in the size
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A
Phylum Porifera-Syconoid Type Sponge:a longitudinal & cross-sectional view. Note the osculum (A), spongocoel, radial canals & the choanocytes lining the radial canals. A magnified view of a radial canal showing individual choanocytes is included. [fig 1.4]
Dr. PARVISH PANDYA’s presentation
Phylum Porifera-Syconoid Type Sponge (CS): This is a close-up of a cross-section through the radial canals of asyconoid-type sponge. Note the radial canals, the choanocytes lining canals, & osculum [fig 1.4]
Dr. PARVISH PANDYA’s presentation
Leuconoid SpongeLeuconoid SpongeOsculumOsculumOsculum
Excurrent canalExcurrentExcurrent canalcanal
Incurrent poreIncurrent poreIncurrent pore
Incurrent canalIncurrent canalIncurrent canal
Choanocytechamber
ChoanocyteChoanocytechamberchamber
Dr. PARVISH PANDYA’s presentation
These are examples of the most complex sponge type. The choanocytes are located in the many flagellated chambers. Any large sponge is most likely a leuconoid- type sponge.
Phylum Porifera- Leuconoid Type Sponge:
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Types of Sponges (Canal Systems) cont.
C. Leuconoid Sponges
• No atrium; several small chambers in which choanocytesare located • There is a whole series of incurrent canals leading to the choanocyte chambers; water is discharges through excurrentcanals• The leuconoid sponges exhibit a significant increase in surface area and are, therefore, among the largest sponges
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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Sponge Body Forms
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Sponge Reproduction• hermaphroditic or monoecious.• Sperm leaves a sponge via the osculum, and enters a sponge by the currents generated from the choanocytes.Fertilized eggs develop into ciliated free-swimming larvae called parenchymula larvae Sponges can reproduce asexually by fragmentation
• Many of the freshwater sponges can produce asexual bodies called gemmules, aggregations of cells that are enclosed in hard outer covering containing spicules
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Asexual ReproductionAsexual Reproduction
MicropyleMicropyleMicropyle
SpiculeBuddingFragmentationGemmule formation
-survive freezing
BuddingBuddingFragmentationFragmentationGemmuleGemmule formationformation
--survive freezing
SpiculeSpicule
survive freezing
Dr. PARVISH PANDYA’s presentation
Sexual Reproduction
• Monoecious– Both male and female
• Sperm and egg derived from choanocytes• Ciliated larva
– Swim to new location
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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Hypothesis of Multicellularity
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Sponge Taxonomy
Class Calcarea(Calcispongidae)
• Only sponges that possess s composed of calcium carbonate. • have 3-4 rays, and do not have hollow axial canals. • Today, their diversity is greatest in the tropics, predominantly in shallow waters
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Taxonomy cont.
Class Hexactinellida (Hyalospongiae)
• Glass sponges; characterized by siliceous of six rays intersecting at right angles• Widely viewed as an early branch within the
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Taxonomy cont.
Class Demospongiae
• Greater than 90 percent of the 5,000 known living sponge species are
Yellow sponge growing on a wallon a Caribbean reef.
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The End