Question

Name the cells that line the spongocoel in Sycon.

Answer 1

Hint: The sponges have the least complex functionality in the whole Animal kingdom. The entry and exit of all the substances from the body occur via pores. They do not have separate systems for excretion, circulation etc. but maintain the flow of water to process all the materials.

Complete answer:
Spongocoel is the large vacuole or cavity in the sponges. Sycon is a member of sponges. They have the simplest organization of the cell. They have spongocoel to enter the water in the body through ostia and exit through osculum the larger openings.
The spongocoel in sponges inlined by Choanocytes on the inside and pinacocytes on the outside.

Choanocytes are the cells that will be present on the interior of the sponges. This will have attached flagella that will help it to move. The microvilli on the flagellum are connected to the flagella by a thin membrane. These choanocytes will make the choanoderm. Their primer function is to generate water currents through the sponges. This also helps to fetch and ingest the food by phagocytosis.

Pinacocytes line the spongocoel and incurrent canals. Their main function is to maintain the size and structure of the sponge via contractions and relaxations. There are 3 types of pinacocytes- basic pinacocytes, exo pinacocytes and endo pinacocytes.

Note: Choanocytes are found on the surface of asconoids, in radial canals of syncoid and entirely in the leuconoid sponges. Sponges move with the help of flagella, collar and cell body. Choanocytes can be used at the time of reproduction also. Sponges also have stinging cells on their tentacles.