After measurements, it has been released

Mar 11, 2009 07:37 GMT  ·  By

As part of a bid to track down and protect the largest freshwater fish in the world, a team of scientists who have been part of a National Geographic expedition have captured what may be the largest fish in the world, a stingray weighing in excess of 771 pounds, although some claim that the creature could tip the scales at even more. The stingray was caught in central Thailand on January 28th, was tagged, and then set free again. Scientists are now tracking it, to observe its habitat and maybe find clues as to what allowed it to grow to such an impressive size.

“While the photo is genuine and there’s no denying that this is a huge stingray, the stingray in the photo was never weighed,” University of Nevada in Reno (UN) researcher Zeb Hogan, a conservation biologists who has also been the leading researcher of the expedition, explains. He says that this type of fish, the freshwater giant stingray, is the largest of its family, and that it can only be found in select locations around the world, such as rivers in Southeast Asia and Northern Australia.

The team, he shares, has been very fortunate to be able to find such a massive exemplary without too much hassle. Naturally, it's possible that even heavier stingrays may exist in other rivers, but, for now, the recent capture is the largest known one in fishing history. Details of the trapped fish, which was caught using only a rod and a reel by volunteer angler Ian Welch, will be aired on National Geographic Channel very soon.

“In terms of disk width, this is the second largest stingray I’ve seen, the largest was in Cambodia in 2003. This recent fish was very thick, so it may have weighed more. It's clear that this species of giant freshwater stingray has the potential to be the largest freshwater fish in the world,” Hogan adds. However, he specifies that the current official record holder for the world's largest fish is a specimen caught in Thailand in 2005, a Mekong giant catfish, weighing in at approximately 646 pounds (293 kg).

According to the classification given to this type of aquatic creatures by the International Union for Conservation of Nature (IUCN), the stingrays are vulnerable to extinction, which makes the new study all that more important. Thus far, the international team has tagged about 18 giant fish, and they are tracking their movements via an underwater network of sensors, which is able to pick up the signals emitted by the tags implanted in the animals.