The highly invasive suckermouth catfish, globally recognised for rapidly degrading aquatic ecology and biodiversity, is in commercial production in Bangladesh, revealed a government probe.
The alien fish, once introduced for ornamental purposes for aquarists, is now naturally breeding and is found in almost all water bodies except in the coastal areas, a government probe said.
‘Fries of suckerfish (suckemouth catfish) are being produced at hatcheries in Mymensingh, Noakhali, Lakshmipur, Cumilla, Bogura and Naogaon and through individual initiatives who are farming at their houses,’ read a paragraph of the report on the probe conducted by the Department of Fisheries.
The investigation was launched in late December 2020 after the strange-looking armoured catfish was frequently spotted in rivers, sparking social media concerns and mainstream media coverage of the alien fish.
The probe report submitted on February 28 made half a dozen recommendations including an immediate ban on the import, production and marketing of the catfish.
The report discussed evidence, including interviews of hatchers and ornamental fish traders of Dhaka’s Katabon, regarding the fish’s secret but widespread commercial farming.
Focused on field inspections confined to Dhaka and adjacent areas, the probe, carried out by two fisheries officers, also considered reports from their local offices.
‘We do not know how many hatcheries or individuals are involved in Suckermouth catfish farming. A countrywide study is needed to get a complete picture of it,’ said Sarker Mohammed Rafiqul Alam, who headed the probe.
One of the hatchers interviewed in Feni admitted to the government investigators about producing and marketing a certain variety of the species other than the one with black stripes.
There is also evidence of the catfish being farmed alongside Tilapia in Keraniganj, where the presence of the catfish can be seen around the year in rivers and canals.
The fish is also found year-round in the River Buriganga and the Turag, though its presence dramatically increases between June and November, according to the government report.
The government investigators went searching in a number of rivers, canals and ponds in and around Dhaka and found the fish in five of the 11 spots.
They caught the biggest one measuring over 1.5 feet in a Badda pond.
The catfish was also found in Uttara, Dhaka Cantonment, DND canals and Savar.
The presence of the fish was also confirmed by district offices of the fisheries department in Narayanganj, Netrokona, Kishoreganj, Moulvibazar, Sylhet and Habiganj.
Bangladesh Fisheries Development Corporation confirmed that they found the fish in Kaptai Lake with the largest one caught in 2017 measuring nearly 1.5 feet.
Citing individual studies, the government probe said that the fish was also spotted in the River Padma, the Meghna and many other rivers and canals in Bogura, Gaibandha, Rajshahi and Jhinedah between 2007 and 2012.
‘The invasion has occurred over the years as we overlooked and neglected the problem, allowing it to grow out of proportion,’ the report concluded.
On the characteristics of the catfish, the report said that it burrows as deep as 1.5 meters into banks of water bodies for laying eggs over a prolonged breeding season extending from March to September.
A female can lay up to 3,000 eggs with males guarding their burrows until the eggs are hatched but their fries learn to move around in the water on their own, according to the report.
The fish feeds on phytoplankton, detritus, algae and eggs of other fishes, the report said, adding that it loves to scrape floors of water bodies for food, turning water turbid and uprooting aquatic plants, home to aquatic lives and local fishes.
Covered in bony plates, the report said, the fish is the last target of predators and it can easily kill water birds by moving its bony dorsal fin.
The fish can survive with minimum oxygen for its blood contain high levels of glucose and lactate, said the report.
In 2018, the USA categorised a species of the catfish, Hypostomus plecostomus, highly risky considering its ecological impacts, including the ability to rapidly monopolise nutrient resources.
The government probe said that the mostly found species of the catfish in Bangladesh is Pterygoplichthys pardalis, also known as the Amazon sailfin catfish.
Individual researches reported spotting two more species of the catfish, including the one the USA consider highly risky.
In Mexico the annual loss from disrupted freshwater fishing stood at $16.4 million after the proliferation of the catfish.
The UK-based Centre for Agriculture and Bioscience International said once established in nature the removal of the catfish is likely to become impossible.
The government report recommended consumption of the catfish as food for a measure to control its population citing its high food value in its native South America.