Question

Choose the correct pairing of fish and it’s feeding zone from the choices given below
a. Rohu -Bottom zone
b. Catla-Middle zone
c. Common carp-Bottom zone
d. Mrigal-Surface zone

Answer 1

Rohu, Catla ,Common carp and Mrigal all are freshwater fishes. Depending on their habitat different organisms live in different zones in the lake. Detrivores usually live in the bottom zone in freshwater detritivores (also known as, detritus feeders, or detritus eaters) are heterotrophs that receive nutrients from detritus.

Complete answer:
Freshwater communities are composed of many organisms depending on the physicochemical and biological properties of the freshwater environment.

Indian freshwater fishes	Feeding nature	Feeding zone
Catla	Zooplankton feeder	Surface feeder
Rohu	Omnivorous	Column feeder
Mrigal	Detritivorous	Bottom feeders

**Exotic freshwater fishes	Feeding nature	Feeding zone
Silver carp	Phytoplankton feeder	Surface feeder
Common carp	Detritivorous ,Omnivorous	Surface, Column , marginal areas

Detrivore usually live in the bottom zone in freshwater Detritors (also known as, detritivores, detritus feeders, or detritus eaters) are heterotrophs that receive nutrients from detritus (decomposition of plant and animal parts and faeces) and is in abundant amount at the bottom of lake in the above options Mrigal and common carp both are detritivores so they occupy the bottom zone of the lake.
Hence, the correct answer is option (C).

Additional information:
Fresh water is divided into mainly three zones:
• Littoral zone: The littoral zone borders the coast (and thus accommodates root vegetation) and the rate of photosynthesis increases to a point known as the level or depth of light compensation equal to the rate of respiration.

• Limnetic Zone: The limnetic zone contains all the water outside the coastal zone and compensates for the light. The limnetic zone receives photosynthetic activity of phytoplankton and oxygen content from the atmosphere just above the lake surface. The source of oxygen in the atmosphere is very important when sleep is disturbed by wind or human activity.

• Profundal Zone: Land and deep water areas of the lake outside the effective light penetration depth are called the profundal zone. In temperate northern latitudes, where winters are long and harsh, this zone has the warmest water in the lake in winter and coldest in summer.

Note: Catla also known as fresh water fish is found in most Indian rivers. Catla catla, in India ,is commonly known as Bhankur.This fish is herbivorous.
Labeo rohita and Labeo calbasu are the common freshwater edible cars The fish is herbivorous but in the juvenile phase it is carnivorous.
Clarissa Magur are commonly found in fresh water and brackish water. They are omnivore. They are disturbed in Ganga and Brahmaputra river basins of India, Nepal ,Bhutan and Bangladesh.