Question

Type of spongocoel/canal system found in Leucosolenia is:
a. Ascon
b. Leucon
c. Sycon
d. Rhagon

Answer 1

Hint: The canal system is the name given to the water circulatory system present in sponges. Sponges are the characteristic feature of the phylum Porifera. As we already know, the Canal system is also known as the auriferous system. The canal system has great importance. It helps in food procurement, respiratory gas exchange, and also in the evacuation.

Complete answer:
> Option A. The Ascon canal system is the simplest type of canal system which is normally found in Ascon sponges like Leukopenia. The spongocoel is lined by choanocytes in this only canal system. The Ostia is epitomized by cells called porocytes. These cells have an intra-cellular canal interior to them.

> Option B. Syconia canal system type of canal system is developed from the Ascon type due to the folding of the Ascon body wall in a horizontal direction. The spongocoel is generally lined by pinacoderm and the choanocytes are constrained to small compartments which are known as radial chambers.

> Option C. Leuconid canal system is the most complex system of the canal. It progresses from syconia type due to the folding of walls of radial canals.

> Option D. The Rhagon type of canal system is formed in the duration of the development of the embryo. Each compartment is unswervingly opened out at the body surface by the means of a prosopyle and into a spongocoel through an apopyle.

Hence, the correct answer is option (A).

Note: The cells in the Ascon extend radially into the mesenchyme and open directly into the spongocoel. The Leuconoid canal system is found in leuconoid sponges. As we know, the Rhagon type of canal system is found in sponges of class Demospongiae. The numerous perforations which present on the body surface of the sponges for the purpose of ingression and egression of water current are an important element of the canal system.