4 porifera spicules & canal system

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.


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 [email protected] a lot and have fun in teaching & learning Zoology….

http://esg-www.mit.edu:8001/esgbio/cb/org/organelles.html

http://esg-www.mit.edu:8001/esgbio/cb/org/organelles.html

http://faculty.pnc.edu/jcamp/parasit/parasit.html

http://www.amnh.org/rose/hope/creatinghope/

http://www.biosci.ohio-state.edu/~zoology/eeob405/

http://www.tulane.edu/~wiser/protozoology/pwpt/

http://www.iep.water.ca.gov/suisun/photos/wildlife.html

http://www.uta.edu/biology/marshall/2343/

http://www.uta.edu/biology/faculty/faculty.html

http://www.okc.cc.ok.us/biologylabs/Documents/Zoology/PowerPoint.htm

http://bio.fsu.edu/

http://www.aw-bc.com/

http://www.nhm.org/

http://www.geo.cornell.edu/eas/education/course/descr/EAS302/presentations/

mailto:[email protected]


PHYLUMPORIFERA


Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Simple Sponge Morphology


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


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


Spicule

• Skeleton of sponge– Calcium carbonate– Silicon– Collagen


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


Archeocyte

• Amoeboid cells• Receive food from

choanocytes• Differentiate into other

cell types


Sclerocyte

• Produce spicules


Asconoid SpongeAsconoid Sponge

OstiumOstiumOstium

SpongocoelSpongocoelSpongocoel

OsculumOsculumOsculum

PorocytePorocytePorocyte


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]


Phylum Porifera-Asconoid Type Sponge: note spicules, spongocoel, osculum & bud [fig 1.3-A]


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]


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)


Syconoid Sponge

Osculum

SpongocoelIncurrent Canal

Radial CanalOstium

Choanocytes


Syconoid SpongeScypha (Grantia) xs

Ostium

Incurrent Canal

Spongocoel

ChoanocytesRadial Canal


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]


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


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]


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]


Leuconoid SpongeLeuconoid SpongeOsculumOsculumOsculum

Excurrent canalExcurrentExcurrent canalcanal

Incurrent poreIncurrent poreIncurrent pore

Incurrent canalIncurrent canalIncurrent canal

Choanocytechamber

ChoanocyteChoanocytechamberchamber


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:


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



Sponge Body Forms


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


Asexual ReproductionAsexual Reproduction

MicropyleMicropyleMicropyle

SpiculeBuddingFragmentationGemmule formation

-survive freezing

BuddingBuddingFragmentationFragmentationGemmuleGemmule formationformation

--survive freezing

SpiculeSpicule

survive freezing


Sexual Reproduction

• Monoecious– Both male and female

• Sperm and egg derived from choanocytes• Ciliated larva

– Swim to new location



Hypothesis of Multicellularity


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


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


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.


The End