Scientists have discovered an alien invader fish that has been found in KwaZulu-Natal, which potentially pose such a serious threat that they will be controlled by environmental legislation currently being drafted. It is informed that armoured catfish or “plecos” (Pterygoplichthys disjunctivus) have been found in the uMhlathuze and Nseleni rivers in the Empangeni district.
It is said that in natural water systems, they could pose a threat to indigenous fish stocks and subsistence and commercial fishing. Professor Paul Skelton, a freshwater fish expert and managing director of the SA Institute for Aquatic Biodiversity (SAIAB) in Grahamstown, confirmed that these fish are of particular concern in KZN because the freshwater environment along the coast is suitable for them and they could invade extensive areas.
Skelton expressed that it is not sure how this alien fish got into local waters, but most likely they were released by, or escaped from, aquarists in the area. He added that they have been in the aquarium trade for several decades now — I am not sure exactly when they first were introduced.
He told that plecos are easily distinguished from all African catfishes by their armour — a series of bony plates along the body. Spokesman for Ezemvelo KZNWildlife Jeff Gaisford appealed “in the strongest terms” for people who own plecos not to release them into local rivers or dams.
Robert Karssing, an aquatic research technologist at Ezemvelo and a keen fisherman, appealed to other fishermen who catch plecos in local waters not to release them. He asked the fishermen to freeze them and handover to the authority, and report the location where they were caught.
