Home ›› 03 Dec 2021 ›› Nation
A massive invasion of alien fish in the water bodies of Mymensingh is threatening the aquatic ecology and freshwater fisheries of the district.
Better known as suckermouth catfish or simply sucker, a native to South America, the fish’s invasive characteristic is globally recognised, especially after it invaded North America, the Caribbean and South Asia, causing aquatic degradation and replacing some of their native fishes.
Scientifically named Hypostomus plecostomus, this harmful fish–which is cultivated along with other foreign species of aquarium fish– is now often found in the water bodies of Bangladesh Agricultural University (BAU).
The species poses a threat to the aquatic ecosystem as it is competing with native fishes for space and nutrient sources, said Professor Shakur Ahammad of the Department of Fisheries Biology and Genetics at the university. Accurate information about how this fast-breeding fish came to the water bodies is yet to be known, he said.
This fish was first seen in the coastal districts of Bangladesh a few years back. But it has now spread in places like Sylhet, Mymensingh, Rangpur, which are far away from the coast. This fish is now often caught in Isha-Kha Lake and surrounding water reservoirs of BAU in Mymensingh. Fisheries researchers fear that if it spreads widely, native species of fish will be threatened, said Bangladesh Fisheries Research Institute (BFRI) Director General Yahya Mahmud.
Bangladesh has risen to the third position in the world in fish production, and Mymensingh produces 22 per cent of the total fish produced in the country.
The fishing industry in Mymensingh is likely to suffer in the near future if there are no steps taken to prevent the breeding of this harmful fish, Yahya said, quoting the local fisheries office.
The length of the fish species found in Mymensingh is up to 16-17 inches, and it can live up to 24 hours without water. The fish farmers of the district complained that the fish had entered their enclosures and reduced fish production.
Farmers of the district said that suckerfish eat aquatic insects and algae as well as small fish and fish eggs. Moreover, while fighting with other fish, the fish attack the other fish with their sharp fins, which cause wounds on the body of other fish and later die due to infection. Suckermouth catfish is a voracious species that eat a lot of food and compete with other fish for food supply. Most of the time, native species cannot survive with the competition and gradually become extinct from the water bodies.
Director General of BFRI Yahya Mahmud said that suckerfish can easily adapt to the new environment and can breed quickly. Many people keep it as an aquarium fish in the beginning but later release it in the pond where the fish grows up rapidly. There the fish begins to breed. Since the fish is not delicious to eat, usually no one eats the fish, and there is no demand in the market. There is no research yet on whether there is any health risk for eating the fish.
Yahya also said that once the fish enters a water reservoir, it is very difficult to prevent its spread. When this fish enters the farming pond, it starts competing with other fish for food and shelter. If adequate food is provided from outside, the desired fish production is not available. On the other hand, cultivated fish cannot survive in competition for food or habitat, and thus the fish farmers face losses.
