Some common examples of Porifera
- 1 Sycon
- 2 Hylonema
- 3 T.S. Of Sycon
- 4 L.s. of sycon
- 5 SPICULES OF SPONGES
- 6 GEMMULE
- 7 Cliona
- 8 Euplectella
- 9 Spongilla
DISTRIBUTION-Found in abundance near North Atlantic shores.
HABITAT-It is solitary or colonial marine sponge found attached to the rocks in shallow waters.
• Vase-shaped cylindrical body measuring about 20-30mm in length.
• Each cylinder opens to the exterior by an osculum.
• Body surface contains numerous pores called ostia or incurrent pores.
• Osculum is encircled by a fringe of monoaxon spicules.
• Body wall consists of outer dermal epithelium and inner fllattend epithelium.
• Skeleton comprises calcareous spicules of monaxon,triaxon and tetraxon type.
• Choanocytes(fllagelated cells) are present in radial canals only.
• Water enters the body via ostia and passes into radial canals by prosopyles. Then it reaches to spongocoel through the appopyles and passes out by osculum.
• Reproduction by both asexual (budding and regeneration)or sexual(by ova and sperms).
COMMON NAME-Glass rope sponge
DISTRIBUTION-Found along new England coast.
HABITAT-Marine, found 10-15meters deep in sea.
• Rounded or oval body with a spirally twisted root tuft.
• Spicules of root tuft continue through the sponge body as an axis or collumella and projects above as a gastral cone.
• Root spicules are compact,stalk like,twisted giving the appearance of a rope.
• Middle part of collumella has symbiotic polyps.
• Sekeleton consists of small amphidiscs.
• Extending from all over the surface are small,branching,five- rayed spicules.
T.S. Of Sycon
SCIENTIFIC NAME- Sycon
• Body wall –diploblastic composed of ectoderm,endoderm and mesenchyme.
• Ectoderm is made of pianocytes.
• Mesenchyme contains calcareous spicules,amoeboid cells,collencytesand archeocytes.It is gelatinous in nature.
• Endoderm contains single layer of large fllagelated collared cells(choanocytes) and forms of the lining radial canal.
• Each radial canal opens into central spongocoel by an appopyle.
• Radial canals connected with incurrent canals by prosopyl.
Water(enters) --⇒ostia--⇒incurrent canal--⇒passes into radial canals through prosopyles--⇒ from radial canal into spongocoel by apopyles---⇒leaves spongocoel by osculum
L.s. of sycon
• Body wall is diploblastic and consist of ectoderm, mesenchyme and endoderm. enclosing incurrent and radial canals.
• Ectoderm and dermal epithelium covers the entire outer surface.
• Mesenchyme is composed of amoebocytes,gelatinous transparent matrix and spicules.
• Endoderm or gastral epithelium consists of single layer of flagellated collared cells known as choanocytes and forms the lining of radial canals.
• Spongocoel is lined by flat epithelium.
Water ---⇒ostia ---⇒incurrent canal ---⇒prosopyles ---⇒radial canals--⇒apopyles ---⇒spongocoel---⇒out through osculum
SPICULES OF SPONGES
• Spicules are formed by scleroblasts in the mesenchyme.
• They consists of an axis of organic material around which calcium carbonate or silica is deposited.
• They are of various shapes.
• Depending on presence of main axis and rays they are classified into 6 types-
1.Monaxons-contain single axis growing n one or more directions.
2.Triaxons-contain three axes crossing each other, and have six rays.
3.Tetraxons-have four rays.
4.Polyaxons-have many axes and several rays radiating from a single point.
5.Spheres-spherical in shape in which growth is concentric round a central point.
6.Desmas-are formed bydeposition of successive layers of silica on an ordinary spicule.
• Spicules support and protect the body.
• Microscleres are the smaller flesh spicules found throughoutr the mesenchyme.They are of two types-spires and asters.
• Gemmules are asexual reproductive bodies of freshwater and a few marine sponges.
• It is a small ,hard,ball like structure consisting of an outer capsule and an inner mass of archeocytes.
Capsule is made of two layers,an inner and outer chitinous layers. Outer chitinous layer contains amphidiscs to strengthen the capsule .
Archeocytes is filled with reserve food material formed by trophocyte cells.
• An outlet ,the micropyle is present at one end of the gemmule.
• Under favorable conditions , the mass of cells pass out by micropyle and develops into a young sponge.
COMMON NAME-Boring sponge
GEOGRAPHICAL DISTRIBUTION-Cosmopolatin in distribution but very common in South Carolina.
HABITAT-It is found inhabiting itnterior of coral skeletons, mollusk-shells and other calcareous objects.
• The colour of the species is green ,purple but often light yellow.
• The animal forms a mass up to 22 cm in diameter.
• Larval forms of cliona settle on shells , corals and calcareous objects and bore them forming tunnels and burrows.
• Each tunnel has an opening called osculum.
• The skeleton consists ofmonoaxon tylostyles.
• Canal system leucon type.
• Reproduction sexual by early stage free swimming larva.
• The larva settle down on shells , corals and other calcareous objects ,bores them and forms tunnels.
SCIENTIFIC NAME: Euplectella
COMMON NAME: Venus’s flower basket
DISTRIBUTION: Found in abundance near the Philippine island and west Indies.
HABITAT: Found abundantly in deep waters at the depth of 500 to 5,000 meters in slow running water.
• Long curved, cylindrical body fastened in the mud of sea bottom by a mass of long siliceous root spicules.
• Size of individual varies from 15-30 cm in length and 2-5 cm in diameter.
• Skeleton consists of four and six- rayed siliceous spicules which are interlaced and fused at their tips forming a three dimensional network with parietal gaps.
• Canal system simple synconoid, having thimble shaped radial canals.
• Parietal gaps in the in the network of spicules connect with the spongocoel.
SCIENTIFIC NAME: Spongilla
HABITAT: Abundantly found in ponds, lakes and slow stream growing on submerged sticks and plants.
• Colony is profusely branched exhibiting various shades of green colour due to the presence of zoochlorellae a green alga in the tissues.
• Body wall consists of very thin dermal membrane provided with dermal pores of ostia and several oscula.
• Canal system is ragon type.
• Skeleton consists of siliceous spicules in form of network of smooth or spiny large and small oxeas embedded in the sponging.
• Reproduction both sexual and asexual . asexual by gemmules and sexual by way of unusual free swimming larva characteristic of spongilla.