A fish from the Amazon River basin in South America has been found in Manipur, raising concerns among experts of an invasion of the northeastern state’s aquatic ecosystem by alien species.
This came to light when Amazon Sailfin Catfish, also known as suckermouth catfish, was caught by a fisherman from the Waishel canal in Manipur’s Bishnupur district probably for the first time on April 22. Bishnupur district has the largest freshwater lake in the northeast region.
Experts said the Amazon Sailfin Catfish was found in the Ganga in Bihar’s Patna some years ago and also in the Brahmaputra in lower Assam. But this species was not reported from any other northeastern states yet.
“Report of catching of such alien species from the water bodies of the state is not a good sign because their presence may demolish the aquatic diversity of the region,” Dr Ch Basudha Devi, a senior scientist of the Manipur centre’s Indian Council of Agricultural Research (ICAR), said.
“Subsequently it will affect the region’s biodiversity,” she added.
The one-foot long fish is said to be a fast-spreading species. As per reports, this alga eating fish, which can grow up to 49 centimetres and weigh up to 310gm, has become a local pest to eliminate fish in a few countries.
“Above all, they will start expanding and try to occupy the entire habitat and start competing with our native species, which are in low fecundity rate as there is no native predator to control them,” Yumnam Lokeshwor, an associate professor with Assam Don Bosco University’s department of zoology, said.
Manipur’s water bodies are increasingly becoming populated by alien fish species. Some of them have been let out for commercial purposes by the state while some have been released accidentally from captivity due to lack of necessary regulations.
Yumnam said more than a dozen alien species, including seven authorised exotic food fish, two authorised larvicidal fish, three unauthorised exotic food fish and five other freshwater ornamental fish, were found in the state’s water bodies after their introduction.
“Some of them have already established a good breeding population and have emerged as a threat to the native species,” he said.
The International Union for Conservation of Nature (IUCN) had listed seven native fish of Manipur as endangered freshwater species. Even the state fish, Pengba, has vanished from wild and is only bred in farm ponds.
“Therefore the state fishery authority must adopt new policy to monitor the introduction of new species including the aquarium species (exotic) as this hobby has been increasing day by day,” Yumnam added.
Sharing a similar sentiment, ICAR scientist Basudha also expressed the need to form a state-level assessment committee to monitor the aquarium fish trade and introduction of exotic species.
N Gojendro, the newly-appointed director of the fisheries department, acknowledged the recent development.
Gojendro said they have appraised the matter to his seniors to formulate a comprehensive guideline for importing, culture and marketing of fishes in the state.