October 3, 2023
BALIK PULAU – With just a rod and line, an angler has managed to reel in a cusk eel, a fish that is supposed to be found many kilometres below the sea.
Even marine researchers are surprised by the catch, claiming that it could be possible due to undersea earthquakes that had spooked such deep-sea fish to rise from the depths.
An ichthyologist (fish expert) from Universiti Sains Malaysia (USM) is now trying to convince the fisherman to surrender the fish to science to be preserved in USM’s fish collection.
The oddity was that fisherman Mohamad Hafiz Mohd Ariffin, 37, caught the cusk eel at a depth of 42m, 16 nautical miles southwest of Penang island.
“I was using light fishing tackle to catch baitfish. My sonar reading showed there was just a featureless rocky bottom down below. When I retrieved my line and brought the fish up, I knew it was different.
“I’ve been a fisherman for 18 years and I have never seen such a fish,” he said, adding that when he returned to shore and showed the fish to other fishermen, no one recognised it either.
He said he caught the 30cm-long fish at about 10am last Saturday, and he had been keeping it on ice.
Its pointed tail resembles that of an eeltail catfish (sembilang), and its head is shaped like that of a common croaker (gelama), with two fat barbels extending from its pelvic fin.
Fish living in deep seas, where there is little light, rely on barbels to “taste” the water in their search for food.
Beyond 1,000m, sunlight cannot reach down, and fish there typically have underdeveloped eyes and rely purely on tactile sensation and taste.
When Dr. Khaironizam Md Zain, an ichthyologist at USM, was shown pictures of the cusk eel, he said that it was the first time he had seen an actual specimen of this fish.
“Most cusk eels are deep-sea fish. More interestingly, most of the members’ distribution is in the Atlantic and eastern Pacific regions.
“Few are known from the western Pacific and Indian oceans. I suspected this species has a distribution in the Indo-Pacific region,” he said.
Khaironizam said there were abyssal zones (4,000 to 6,000m) in the ocean near west Sumatra and the Philippines where cusk eel would thrive.
“It is possible that they occasionally migrate to shallow areas, maybe due to foraging and maybe also due to seismic activity somewhere in the Indian Ocean and western Pacific region,” he said.
There is a centuries-old notion, especially in Japan, that the appearance of deep-sea fish within reach of fishermen’s nets and hooks heralds earthquakes.
One theory was that escaping gases, electro-magnetic disturbances, and temperature changes due to seismic activity might drive deep-sea fish to seek refuge in the shallows.
But a comparative analysis published in 2019 of over 300 deep-sea fish sightings and earthquakes in Japan between 1928 and 2011 yielded no correlation.