The Kerala floods have brought, among other things, a number of predatory non-native fish breeds in the waters of the state. A couple of photos and videos making rounds on social media suggest that an Arapaima, a genus native to the Amazon and Essequibo basins of South America was caught by some locals from the Chalakudy river in Thrissur District.
The photographs showed a couple of men holding the fish, that is bigger than an average man. Arapaima is a rare fish species that breathes air from the atmosphere and is a vicious predator.
There are no previous records of Arapaima being spotted in any waterbody in India, but many fish enthusiasts like to keep them in ponds and aquariums for years. It is likely that one of them slipped through during the floods and reached the Chalakudy River. Although only one was caught, how many more are still in the water is still a question. The freshwater rivers of Kerala are the ideal ‘home’ for the giant fish to live and breed without any competition.
While Arapaima does not pose a direct threat to humans, reports of people hooking Red Belly Piranhas from the Vembanad Lake is a matter of concern. A native of South America, Piranhas are fierce hunters that have a reputation for their love for meat. Breeding Piranhas is officially banned in Kerala, but many fish farms and aqua life dealers have kept them illegally.
Another non-native species of fish that was recently spotted in Vembanad Lake is Alligator Gar. The Gar which resembles an alligator is among the largest freshwater fish in North America. They can grow up to 80-100kg and are said to be relatively passive, seemingly sluggish solitary fish that are voracious ambush predators.
Another rampantly spotted non-native species is the African Catfish. Officially banned for cultivation in Kerala, the fish is illegally farmed in various parts of the state, especially in Alappuzha, Idukki and Ernakulam districts. It is ferocious and can survive extreme conditions. The air-breathing fish is found in Africa and the Middle East. The African Catfish that can grow to over 50kg feasts on native fish species, driving many of them to extinction.