Question

What makes a mollusk a mollusk?

Answer 1

The following characteristics makes a mollusk a mollusk:-

i.Body is covered by a calcareous shell and is unsegmented with a distinct head,muscular foot and visceral hump.

ii.A soft and spongy layer of skin forms a mantle over the visceral hump.The space between the hump and mantle is called the mantle cavity in which feather like gills are present.

iii.The anterior head region has sensory tentacles.The mouth contains a file like rasping for feeding,called radula.

iv.They are bilaterally symmetrical,triploblastic and coelomate animals.

v.They are usually dioecious (male and female are separate) and oviparous with indirect development.They have a complete digestive system.

vi.They are second largest animal phylum ,they can be terrestrial or aquatic having an organ-level of organisation.Pila,octopus,pinctada,sepia are comes under this phylum.