Question

Which of the following animals belongs to the phylum Mollusca?
A) Devil fish
B) Dog fish
C) Silverfish
D) Jellyfish

Answer 1

Mollusca is the second-largest animal phylum. The animals belong to this phylum are mostly terrestrial or aquatic and have an organ-system level of organization.

Complete Answer:
- The animals belonging to the class Mollusca are bilaterally symmetrical, triploblastic, and coelomate animals.
- The body is distinct into the head, macular foot, and visceral hump and the body is covered by a calciferous shell. The size of mollusks varies from 20 meters to 1 millimeter and there are some microscopic animals also.
- The region between the hump and the mantle is known as the mantle cavity in which gills are present which look like a feather. They have Aristotle's lantern(chewing organ) which is used for grinding, chewing, and masticating.
- Above a visceral hump, there is soft and spongy skin called the mantle. They secrete hard shells with conchiolin proteins.
- They have both respiratory and excretory functions. In the mouth, they have a rasping organ for feedings known as radula which is a file-like organ.
- Kidneys are known as the Keber's organ. They are mostly dioecious and oviparous with indirect development. The animals belonging to the phylum Mollusca are apple snail, pearl oyster, devil fish, tusk shell, etc.

Hence correct answer is option A.

Note: The alimentary canal of Mollusca is straight or u-shaped or coiled. They have both internal or external fertilization.