PANAJI: A good population of janitor fish, known for its attractive rows of armour plating on its body and reared in aquariums, was found in a fresh water catch in Cansaulim, triggering concern about yet another invasive species encroaching into Goan waters.
Local fishermen casting their net in the pond at Cuelim drew a sizeable catch of sucker fish. Also called sailfin armoured catfish (Pterygoplichthys), the species which is native to South America has already invaded water bodies in Kerala, affecting native fishes and ecosystems.
“I saw a good habitated number, more than 100, of suckers in the catch of Rohu, Tilapia and catfish that were dumped during segregation of the catch,” Stephen Johnson, domestic and wild animal rescuer, said.
While the fishermen were still harvesting the fish, the rescuer’s posts about the fish rejects on social media sparked interest. There is speculation that the catch of invasive species could be more.
“The suckers are hardy and can survive without water for over a day. They compete with natural fish populations and create their own territories in water bodies,” G B Sreekanth, fisheries scientist, Indian Council of Agricultural Research (ICAR), Old Goa, said.
Goa’s fresh water bodies have already been impacted by fast growing populations of African catfish (Clarias gariepinus), posing a threat to local species of ‘tigur’ (Clarias batrachus). While Tilapia (Oreochromis Mossambicus) has established itself in Goan waters over the last few decades, it is another invasive species.
Ignoring the price of a fresh water fish vantto (parcel), Goan fish eaters prefer species from ponds, but the catch is on the decline. “Fresh water biodiversity has been adversely affected by upsurge in Tillapia and African catfish populations,” Sreekanth said.
ICAR had recently conducted a study on local fish species, as they compete with invasive species for survival. Being bottom feeding species, the suckers attack even aquatic vegetation, thereby adversely impacting the ecosystem.
“Awareness needs to be created among the people who keep aquariums as a hobby not to release the sucker fish in wells and ponds,” director of fisheries Shamila Monteiro said.