Question

Catla and rohu are the examples of...................
A) Freshwater fish
B) Marine fish
C) Brackish water fish
D) None of these

Answer 1

Hint: Aquatic ecosystem is the ecosystem in which the organisms which live in water. The aquatic organisms live in sea, oceans, lakes, streams, rivers ponds etc. Most commonly found organisms in water are fish.

Complete Answer:
Some organisms are solely dependent on water for food, shelter reproduction and other life processes. They are known as aquatic organisms. Aquatic ecosystem consists of groups of organisms which are dependent on one another and water for food and shelter. These organisms have certain adaptations to help them survive in water. For example limbs are modified into fins. Gills are present for respiration, streamlined body for swimming. Gills help them breathe in the dissolved oxygen.
Types of aquatic ecosystem
Freshwater- Lakes, ponds, rivers, streams, swamps, wetland, pools came under the freshwater ecosystem. Several fishes like rohu, catla, frogs, shrimps, etc are found in such habitat.
Marine- Marine refers to salt water. It occupies the largest surface area on earth. Sea, oceans come under marine habitat. Organisms like whales, fishes, reptiles stay in this type of habitat.
Brackish water-It is more saline than freshwater but less saline than seawater.

The correct answer is (A) Catla and rohu are the examples of Freshwater fish.

Note: Both rohu and catla are found in rivers and lakes of northern India, Nepal, Bangladesh. Rohu is large silver coloured fish with an arched head whereas catla is large broad head with greyish scales and whitish belly.