GEORGE TOWN: It was frozen in a refrigerator for a week. But when the biologist took it out of the ice and thawed it out, it came back to life and started thrashing.
The suckermouth catfish (ikan bandaraya) is one species that refuses to die.
Universiti Sains Malaysia (USM) biologist Dr Khaironizam Md Zain found that out after he ran an experiment.
“It was frozen solid for a week. Yet it lived again. The fish can also survive in low oxygen and brackish water environments, or being out of the water for a much longer time than other fish. It has a specialised respiratory system of labyrinthine organs that extracts oxygen from the air.
“To avoid desiccation, they may bury themselves in mud or hide in moist places,” said the School of Biological Sciences senior lecturer.In Penang, he said they could cause soil erosion along riverbanks because of how they breed.
“The burrowing behaviour causes soil erosion along riverbanks. They dig deep into riverbanks to create breeding sites, and buildings beside rivers can be threatened when the ground is hollowed out,” he said.
Because Penang has a dense urban population, Khaironizam said soil displacement caused by the burrowing of tens of thousands of suckermouth catfish can lead to severe riverbank instability.
“In Penang, we found a high population of the fish in two rivers on the island – the highly-polluted Sungai Pinang in Jelutong near the City Stadium, and (the similarly named) Sungai Pinang in Balik Pulau.
“On the mainland, they are found in many rivers including canals near padi fields and retention ponds,” he said.
He said eradicating suckermouth catfish would require a collective effort.
“Due to their spiny scales and slimy mucus, which make them unpalatable and difficult to swallow, even predators such as monitor lizards avoid eating them.
“Control measures for these invasive catfish include capture and removal, such as organised fishing events and electrofishing.
“We need to raise awareness among aquarium owners to prevent further releases, with campaigns in pet stores and online resources to educate fish owners on the ecological risks associated with releasing these species into our waters.”
Khaironizam also cautioned the public against eating suckermouth catfish, as the fish may contain hazardous substances such as heavy metals due to their habitats often being contaminated and characterised by poor water quality.
