Biologist Zeb Hogan has been searching for the world’s largest freshwater fish for 17 years. On June 13th, his team discovered it — a giant freshwater stingray, or Urogymnus polylepis.
The rays of light carried out of the muddy waters of the Mekong River in Cambodia were 13 feet long before being returned to the river. And at 661 pounds, it was 15 pounds heavier than the Mekong giant catfish captured in Thailand in 2005. Dr. Hogan said he had previously established the freshwater fish as the largest ever caught.
Giant stingrays of this species have very dangerous poisonous stingrays that can reach up to a foot in length, but are usually not a threat to humans. Often, they are on the market as a source of cheap protein.
Fishers of Cambodia worked to protect the aquatic diversity of rivers in Southeast Asia and caught the largest stingray by Dr. Hogan and his team at the Wonders of the Mekong Project sponsored by the U.S. International Development Agency. I saw the first warning. Team members rushed to a small river island called Preah and lined up three industrial scales. Using a tarp, I lifted the stingray from the water onto a scale and checked its weight.
The discovery occurs less than a month after another giant stingray weighing 400 pounds was caught and released nearby. Two other giant rays were captured this year.
“The fact that the world’s largest freshwater fish was caught in Mekong is noteworthy.” Dr. Hogan Said. “This is a populous area and the river faces many challenges, including a lot of fishing.”
In another first example, Dr. Hogan’s team could attach an acoustic tag to a stingray and track animals for up to a year using an array of 36 underwater receivers recently installed in parts of the river. I was able to do it.
“This is the first fish we’ve tagged since we deployed the array,” said Dr. Hogan, an assistant professor at the University of Nevada, Reno. In the coming months, they plan to tag hundreds of additional fish.
Dr. Hogan believes that the expanse of this river and the deep pools it contains are important breeding grounds for this species, as so many giant stingrays have been captured in recent months, all female. I am. The area is also home to freshwater dolphins, giant soft-shelled turtles, giant catfish, and giant spines, a companion to the carp.
“So it’s a very unique place and very unstudied,” he said. River systems in North America and Europe have received much more scientific attention.
Breaking the world record was not scientifically important, but Dr. Hogan said the presence of this fish is an indicator of the health of its ecosystem. He also hoped that this discovery would remind the local community how special this river is and how much it needs to save.
Large populations of freshwater fish are generally declining due to a combination of factors such as dam construction, overfishing and climate change. And many species of large fish are in danger of disappearing forever.
“In 2020, one of the world’s largest candidates for freshwater fish, known as the paddlefish, was declared extinct,” said Dr. Hogan. “That was very sad news. I felt that the extinction of these big fish would be seen more, rather than breaking the record.”
Fortunately, the story of giant stingrays isn’t the only story these days. Record record for 2021 240 pounds of lake sturgeon Captured and released on the Detroit River. And in May, Almost 300 pounds of crocodile gar Anglers chose to release the animals rather than kill them and weigh them, but they may have broken the Texas record for freshwater fish.
“When we hear about record fish, that’s a good sign,” said Dr. Hogan.