Question

Unio is
A. Edible oyster
B. Marine shellfish
C. Fresh water mussel
D. Sea mussel

Answer 1

Hint: This genus is found in streams, lakes, rivers and ponds etc. The animal is sedentary, but eventually settles down on the bottom of the river or the lake through the mud or sand.

Complete Answer:
- Unio is a kind of mussels, aquatic bivalve mollusks in the Unionidae family. Lamellidens' body is flattened laterally. The front of the body is approximately oval, and the back end is slightly shorter. There is a bilateral symmetrical body in Lamellidens. The length ranges from 5 to 10 cm.
- A rough calcareous shell is entirely covering Unio's soft body. Shell is created by two valves known as the right and left, which are symmetrical and equal halves.
- In freshwater streams, lakes, rivers and ponds, Unio is present. The animal is sedentary, but eventually settles down on the bottom of the river or the lake through the mud or sand. It doesn't go down in the mud, so the rear ends of the valves remain exposed to respiratory water inlet and outlet.
- Unio typically remains at night in shallow water and migrates during the day to deeper water. Unio's food contains microscopic species that are fed by filtering processes, both animals and plants.

Thus, the correct answer is option C. i.e., Freshwater mussel.

Note: The genus Unio is a freshwater mussel. It comes from the Unionidae family, the mussels of the river. It belongs to bivalve mollusks. A shell of bivalve is part of a bivalve mollusk shell. This coating consists of two sections or valves that are hinged. In Unio, both of the valves are hinged backwards by the elastic hinge ligament.