KUALA LUMPUR: The presence of Amazon Sailfin Catfish or ‘Ikan Bandaraya’ could threaten the native fish species and affect water and habitat quality of the Malaysian rivers and lakes, said Universiti Kebangsaan Malaysia (UKM) School of Environmental and Natural Resources Sciences senior lecturer Dr Abdullah Samat.
Besides that, the fish had the potential to weaken the river- bank structure caused by their burrowing habit during spawning season, he added.
“This kind of fish does disrupt our aquatic ecosystem.”
The fish, from the South American continent, is imported as a ‘janitor’ fish for the aquariums and once they have outlived their purpose or gets too big, it’s thrown away.
“Their presence poses a danger to the ecosystem in two ways — threatening native species, and reducing water or habitat quality.
“The condition will depend on several factors such as the population size of the fish itself.
“The fish rigorously disrupts the river bottom and causes continuous high turbidity in the water with their burrowing habit.
“Hence, there is no benefit that we can get from the fish in our waters,” he told the New Straits Times.
Abdullah was commenting on the effect of the alien fish in the rivers, especially in Sungai Skudai in Johor Baru where fishermen had claimed it affected the local river’s ecosystem and their livelihood.
He also said the alien fish could survive and reproduce in a wide range of environmental conditions, from excellent to a very poor habitat quality.
He added they would reproduce throughout the year with the highest peak during the monsoon seasons, thus explaining the large population of the fish in local rivers.
“They can live in many environmental conditions, and have plenty of food (any type of organic matter) as this fish is a detritus feeder and almost no predators.
“They are abundant in many rivers, streams and lakes all over the country especially those flowing through cities and towns,” he added.
Asked on methods that can be used to eliminate or reduce the population of the alien fish, he said the use of piscicide, a chemical substance which is poisonous to fish, could be carried out.
The primary use of the substance (piscicide) was to eliminate a dominant species of fish in water and it is the first few steps in attempting to inhibit different fishes.
Piscicide can also be used to kill parasites and widespread species of fish.