Phylum- Porifera

• Commonly known as SPONGES.

• Generally marine

• Mostly ASYMMETRICAL ANIMALS

• Primitive multicellular animals

• CELLULAR LEVEL OF ORGANISATION.

• Sponges have a water transport or canal system.

• Water enters through minute pores (ostia) in the body wall

• A central cavity, SPONGOCOEL

• Water goes out through the osculum.

• Choanocytes or collar cells line the spongocoel and the canals.

• Digestion is intracellular.

• A skeleton made up of SPICULES OR SPONGIN FIBRES.

• Sexes are not separate (hermaphrodite).

Sponge Predators

In general, sponges aren’t very tasty to most other marine animals. They can contain toxins, and their spicule structure probably doesn’t make them very comfortable to digest. Two organisms that eat sponges though are hawksbill sea turtles and nudibranchs. Some nudibranchs will even absorb a sponge’s toxin while it eats it and then use the toxin in its own defense.

Examples:

• Sycon (Scypha),
• Spongilla (Fresh water sponge)
• Euspongia (Bath sponge)