Question

Glochidium larva is found in
a) Pila
b)Unio
c) Sepia
d)Asterias

Answer 1

A larva is a juvenile form of various animals which is present before they undergo the process of metamorphosis and develop into an adult.

Complete Answer:
For this question, firstly, we will find out the common names of all the options given and the name of their larval stage.

Option a: Pila or Apple snail is a genus of large freshwater snails belonging to class gastropoda. They have amphibious life respiring by means of gill in water and by a pulmonary sac on land. The veliger is the characteristic larva of the class gastropoda. Therefore, this option is incorrect.
Option b: Unio or freshwater mussel. It belongs to class Bivalvia. They are microscopic animals and are omnivorous. Its larval stage is called Glochidium. The larva has sharp spines that project inward from each valve. It attaches to the gills or fins of fish and becomes a temporary parasite. Therefore, this option is correct.
Option c: Sepia or cuttlefish is a marine mollusk. They belong to class cephalopoda. Their head and foot regions are combined and modified into a structure which has eyes and eight tentacles, hence the name cephalopod. Therefore, this option is incorrect.
Option d:Asterias or starfish belongs to class Asteroidea of phylum Echinodermata. Its body is star-like. Its larval forms are bipinnaria and brachiolaria. Therefore, this option is incorrect.

Hence the correct answer is option ‘B’.

Note: In adult unio , the shell is made up of two halves called valves and it covers the soft body. The two valves are symmetrical and are also equal.