A fisherman in northern Cambodia has been impressed by what researchers say is the world’s largest freshwater fish – something relatively little known to scientists.
The 42-year-old fisherman caught a fish that weighed 661 pounds – about 13 feet long – near the remote island of the Mekong River in the Stung Tren area. A team of scientists from the Wonders of Mekong research project helped mark, measure, and weigh the ray before it was released into the river. The research team believes it was healthy when it was released and expects it to survive.
The tag – which emits an acoustic signal – will allow researchers to monitor the fish’s movements, and they hope to learn more about the behavior of its species in the Mekong.
The capture “shows just how little we know about these giant freshwater fish,” said Jeb Hogan, a fish biologist at the University of Nevada. “You have a fish that has now set a record for the largest freshwater fish in the world, and we know a little bit about that.”
The fisherman, Maul Tun, caught the giant stingray by hook and line on the evening of June 13 and then contacted the researchers the next morning.
Researchers with the wonders of Mekong have already installed underwater receivers in northern Cambodia as part of a project to monitor migratory fish in the river.
Hogan, presenter of National Geographic’s “Monster Fish” television series, said, “This is a particularly healthy length of river with deep pools – 90 meters deep pools.” “We began to focus on the area as the most important river extension for biodiversity and fisheries, and the last refuge of these large creatures.”
For months, the research team has been in contact with local fishermen, asking them to contact them if they go fishing significantly. The team has assisted in two major freshwater stingray releases in recent months. The record-breaking fisherman was given the market price for his fish.
“It works because fish is not the most valuable food fish,” Hogan said.
Hogan said not much is known about the giant freshwater stingray. This creature has a “banana-sized” mouth without teeth, but has “catch bands” to crush prey.
“They have found shrimp, mollusks and small fish at the bottom. They can suck them up with this banana-shaped mouth,” Hogan said.
Fishermen have reported catching three female stingray fish in the area over the past two months, Hogan said. Scientists say the site could be an important seasonal collection site for giant freshwater stingrays, and a puppy playground for teenagers.
The research team plans to mark a few hundred large fish in the Mekong River to better understand fish migration and local habitat in the Upper Cambodian Mekong.
“There is potential for hydropower development right where these stingrays are caught,” Hogan said. “Before development, we want to understand the importance of this area, which in a sustainable way is impossible.”
Hogan said the Cambodian government has expressed interest in developing a protection plan for giant freshwater stingrays.
Upper Mekong Mekong is also home to giant catfish and other species of large freshwater fish.
Worldwide, “most large fish species are endangered and their population is declining. The Chinese paddle was declared extinct by 2020, ”Hogan said. “We need to do more to protect these freshwater habitats.”
The former world record holder for the 646-pound Mekong giant catfish was caught in the Mekong River in 2005 in Thailand.
There are also large canned fish that spend time in fresh and saltwater, such as beluga sturgeon.
“This is the record for the largest fish to have spent their entire lives in freshwater,” Hogan said of the recently caught ray.
“Friend of animals everywhere. Devoted analyst. Total alcohol scholar. Infuriatingly humble food trailblazer.”