Piranha (Pygocentrus nattereri)|
(Image Credits: Gregory Moine/ WikiMedia Commons under CC by 2.0)
Native fish fauna of Indian rivers gets yet another threat to their existence. According to researchers from India’s premier wildlife research body, Wildlife Institute of India (WII), a new ferocious predator fish has entered the Godavari River basin in Andhra Pradesh. Red-bellied Piranha (Pygocentrus nattereri), a known invasive species, was never reported from river systems in India before.
Native to Brazil, Red-bellied Piranhas are usually found in the Amazon and other coastal rivers, interconnected wetlands and canals of Brazil. As per earlier research, these ferocious predators are known to attack even healthy animals for food, not to mention other fish species. Often, when a predatory invasive species is introduced, it wipes away the native species, either by predation or through competition for food resources.
As per an observation recorded by WII researchers, J.A. Johnson, R. Paromita and K. Sivakumar in MIN, an official newsletter from the IUCN-SSC Freshwater Fish Specialist Group South Asia and the Freshwater Fish Conservation Network of South Asia, the Red-bellied Piranha was found from Rajamundhry.
“Our preliminary enquiry in the field revealed that this species is occasionally found in fisherman catch at Dhawaleshwarm barrage in Rajamundhry,” says the note published in MIN. As per the researchers, Red-bellied Piranha is being cultured around the Godavari River mainly in inland water and canals, from where it could have reached the Godavari River.
The situation is alarming, warn the researchers. “As it is a predatory and aggressive carnivorous fish, it may compete with native species for food and other resources, which will eventually lead to the decline or even extirpation of many native fishes in the river system”, they said.
As in case of many other major invasive threats to the Indian fish fauna, here again aquarium trade is the culprit of introducing this Brazilian native to Indian waters. According to Ichthyologist Dr. A. Bijukumar, Red-bellied Piranha was introduced in India as part of illegal aquarium trade. In a study published in 2000, he has warned that the fish, if establishes itself in natural streams, would be dangerous. The notorious fish is now available for purchase in many aquarium shops.
According to a study published in 2011 on non-native fish species in India, not less than 324 alien fish species have been introduced in India, mainly as ornamental fishes for aquarium trade, for cultivation and for killing mosquito larvae. However, many of them have turned invasive and destructive to the existence of native fish fauna. Many of these invasive fishes are threatening endemic fish diversity of Western Ghats, a world heritage site.
Researchers warn that unless agencies and activists take immediate steps to bring awareness to the fish farmers and aquarium traders to bring down the production and distribution of this potential invasive species, Red-bellied Piranhas may soon be detrimental to the fish diversity of Godavari basin.