Question

What do you mean by exotic fishes? Name three exotic fishes that are being cultured in India?

Answer 1

Hint: These species originated in other countries and have established culture technologies and the economics of production and marketability. These species are compatible and do not compete with valuable native species leading to its decline.

Complete step by step answer:
Import of several fishes from various foreign countries into the Indian freshwater for the culture of these fishes. As these fishes do not belong to our country i.e., they are non-indigenous to our country, and hence they are called the exotic fishes.
Three important exotic fishes that are cultivated in India are:
- Common carp
- Silver carp
- Grass carp
There exist several advantages and disadvantages to the cultivation of exotic fishes.
Advantage: The common carp can breed even in pond water and thus the farmers do not have to go and collect the seeds from the river. Also, the common carp fish are omnivorous and they are a scavenger, thus helps in keeping the pond clean without pollution.
The silver carp will mature within one year in the Indian climatic conditions whereas it takes 5-6years in its resident habitat. It will also feed on the phytoplankton and thereby maintain them under check.
The grass carp feeds on various aquatic vegetarian foods and is used to control the weeds. The excreta of this fish are semi-digested food which is eaten by omnivorous fishes. Additionally, these excreta serve as a fertilizer in the pond.
Apart from the above advantages, nearly 288 exotic fish species are beautifully colored and serve as ornamental fishes. Guppy and Gambusia affinis are larvicidal fishes that have been introduced to control the mosquito.

Note: Disadvantages: The exotic fish introduction into various habitats in India might lead to biodiversity loss. The flesh of the grass carp is poor in quality and has an unpleasant smell.