Question

Type of spongocoel found in Leucosolenia is
(a)Ascon type
(b)Leucon type
(c)Sycon type
(d)Rhagon type

Answer 1

Hint: This is the simplest type of canal system. It has an aperture which is lined by a flagellated choanocyte cell. It allows water to enter Inside the body and flows in canals in criss-cross manners.

Complete Answer:
The Ascon type of canal system is found in Leucosolenia and other homocoela. In this system, the water enters through ostia into spongocoel and goes out of the body through the osculum. Ostia is present on the surface of the body that directly leads to spongocoel while osculum is present on the distal free end of the sponge body.
Leucosolenia is a small-bodied, soft branching, and colonial marine sponge. The shape of Leucosolenia is vase-like with a whitish-yellow color. Each individual consists of an osculum at the terminal end and irregular horizontal tubes at their bases. There is a cavity present in the tube is known as the paragastric cavity or spongocoel.

-Digestion in Leucosolenia is intracellular mainly occurring in food vacuoles which are acidic at first and then alkaline.
-Respiration and excretion are going together by osmosis without the help of special structures.
-Leucosolenia reproduces asexually by budding and sexually by the formation of gametes.
-It has a remarkable power of regeneration means each piece of broken Leucosolenia is growing into a complete individual.

Additional information:
Sycon type: Sycon type canal system is found in syconoid sponges like Scypha. The body of this canal is secondarily folded to form radial canals. It opens through an opening called apopyle. The spongocoel of this canal system is narrow and without flagellated cells.
Leucon type: In this type of system, the radial canals are divided into small rounded or oval flagellated chambers which are formed by further folding of the body wall. It is found in the Spongilla.

So, the correct answer is ‘Ascon type’.

Note:
-Pinacocytes line the spongocoel and help in maintaining the size and structure of sponges.
-Amoebocytes are amoeboid cells that present in the mesenchyme of sponges. These cells contain RNA and self- replicating in nature.