Fishing can be exhilarating and also surprising at times like in Cambodia when fishers landed up with an enormous stingray. From the depths of the Mekong River they brought out this stingray which had eaten up a fish snagged on the line, said an article in livescience.com.

It was a giant freshwater stingray whose scientific name is Urogymnus polylepis, and it had been netted by local residents of northeastern Cambodia’s Stung Treng province. This news was conveyed to the Wonders of the Mekong project, a conservation group run by University of Nevada, Reno (UNR), in tandem with local fishing authorities.

The giant creature was removed from the fishing line, measured and then let go in the water. Weighing 180 kilograms, it was 6 feet wide and 13 feet in length which included its six-inch venomous jagged spike, as per a statement by UNR representatives.

Talking to Live Science, Zeb Hogan, UNR fish biologist informed that giant freshwater stingrays are the world's largest stingray species and "are contenders for the title of world's largest freshwater fish”.

Hogan is the director of the Wonders of the Mekong project.

Not much is known about these fishes as catches such as these Hogan said are “almost never reported”, adding that "which also makes it difficult to determine true abundance or population trends."

There have been reports about even bigger giant freshwater stingrays been caught. "The size of this stingray was surprising. But what's more surprising is that it's dwarfed by accounts of [individuals] twice the size reported by fishermen in the same area,” remarked Hogan. For example, one which was caught in Thailand in 2009 was guessed to be between 249 and 349 kilograms but this was never confirmed officially.

The record of the largest fish in this river is held by Mekong giant catfish caught in Thailand in 2005 and it scaled 293 kilograms.

Mekong River passes through many countries which include China, Myanmar, Laos, Thailand, Cambodia and Vietnam and it is the habitat of many big aquatic species. Among these are giant softshell turtles, Irrawaddy dolphins, giant goonch catfish, giant bards, giant sheatfish and Mekong giant catfish said the statement. According to Hogan, “this remote and relatively pristine stretch of the Cambodian Mekong River appears to be the last place on Earth where all of these iconic giant freshwater species live alongside one another.”

The big sized species come into being at Mekong River thanks to the varied habitats it offers. Among these are sand bars, deep pools, islands and braided channels which as per Hogan "provide refuge and space for the species to grow”. Described as one of the world’s “most productive rivers”, he added it provided plentiful of food for larger animals.

There has been a growing concern about the state of Mekong River due to overfishing, fragmentation of habitat and water pollution because of river development. This in turn has made giant freshwater rays endangered as per the International Union for Conservation of Nature Red List of endangered species.

Also read: In a startling study, scientists discover that clever fishes can add and subtract!