Question

Give a brief account on the canal system in sponges.

Answer 1

In Porifera nutrition is done by the current of water and it is managed by the canal system. In porifers, four type of canal system is found

(1) Ascon type- this is the simplest type of canal system in that ostia are presented on the outer surface of the body and directly flows to spongocoel .that are line by flagellated choanocytes cells and water goes out through osculum

That type is found in Leucosolonia

(2) Sycon type- It is characteristic of syconoid sponge. in this body, wall is secondary folded to form in current and radial canals that open into spongocoel by an opening called apopyle and further both types of canals are interconnected by prosopyle . Ostia is presented on outer surface Ex- Gratia

(3) leucon type - In this type canals further divided into rounded and oval flagellated chambers Ex- Leucosolonia

(4) Ragon type - It is found in the larval form of spongilla.