Exotic species of fish invading Ganga

Exotic species of fish, hitherto unknown to the Indian sub-continental waters, are now fast invading the Ganga, reports V K Tripathi.

Exotic species of fish, hitherto unknown to the Indian sub-continental waters, are now fast invading the Ganga.

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Discovery of a genre- Pterygoplichthys anisitsi-an aquarium specimen of South American orgin from Patna's Collectorate ghat recently has not only thrilled Bihar biologists but also prompted them to investigate whether increase in the number of foreign species has affected the shaols of native varieties used as fish delicacies.

The new species, hitherto unreported from South East Asian countries, was first discovered in Ganga from the same ghat in June last year. The recent netting of a young one measuring 11 centimeters has surprised scientists in India and the US.

Discovered and reared in the Environmental Biology labortaory of Patna University, the fish however, died after surviving a few months.

Prior to the latest find, four other foreign species of fishes, Thai Mangur, Silver Carp, Grass Carp and Tilapia, had been traced in abundance in the stretch of the Ganga passing through Bihar.

"The latest discovery has provided new momentum to research. Scientists had feared, that being a burrower in nature and inhabiting the riverbanks the 'intruder' species could de-stabilize the native species. Feeding on the same zooplanktons, the new variety could also cause scarcity of food to local varieties thus affecting the fishery sector, said Dr RK Sinha, expert on the Gangetic eco system.

He said foreign weeds and grasses have caused enormous loss to the Gangetic eco system. Intrusion of exotic fishes of a predator nature could prove a threat to gangetic aquatic life.