A giant female stingray weighing almost 300kg and measuring around four metres from snout to tail was caught on 13 June by a local fisherman south of Stung Treng in north-east Cambodia. According to scientists from Wonders of the Mekong, a US-Cambodian research project, the individual caught in the Mekong River is the world’s largest recorded freshwater fish.
“When you see a fish this size, especially in freshwater, it is hard to comprehend, so I think all of our team was stunned,” said Zeb Hogan, leader of the Wonders of the Mekong. “The fact that the fish can still get this big is a hopeful sign for the Mekong River,” he added.
The previous record for the largest freshwater fish caught was held by a Mekong giant catfish that weighed 293kg and was captured in 2005.
After the fisherman alerted the Wonders of the Mekong Project – Wonders of the Mekong are working closely with local communities to get alerted when a giant stingray is caught during fishing – the stingray was tagged with an acoustic tag by FISHBIO researchers, before it was safely released back into the Mekong River.
The tag will send tracking information about giant stingray behaviour to the researchers for up to a year. “The giant stingray is a very poorly understood fish. Its name, even its scientific name, has changed several times in the last 20 years,” Hogan said.
“It’s found throughout south-east Asia, but we have almost no information about it. We don’t know about its life history. We don’t know about its ecology, about its migration patterns.”
As the sighting is the fourth female giant stingray sighting in the area in the past two months, researchers believe that this could indicate that the species might be spawning here. They hope that the data from the acoustic tag will help shed some light on the migration and behaviour patterns of this elusive species.
“Big fish globally are endangered. They’re high-value species. They take a long time to mature. So if they’re fished before they mature, they don’t have a chance to reproduce,” Hogan said and added: “A lot of these big fish are migratory, so they need large areas to survive. They’re impacted by things like habitat fragmentation from dams [and are] obviously impacted by overfishing. So about 70% of giant freshwater fish globally are threatened with extinction, and all of the Mekong species.”
Watch a video with the giant stingray here.
Images by FISHBIO and Ocean Image Bank – Connor Holland.