Scientists rediscover Freshwater Moray here after 84 years

By Ifham Nizam

Sri Lankan scientists have recently rediscovered Gymnothorax polyuranodon, commonly called Freshwater Moray, after 84 years, last sighted here in 1937.The fresh discovery has been made by a team comprising research scientists Hiranya Sudasinghe, Tharindu Ranasinghe and Lukas Rüber.

Tharindu Ranasinghe told The Sunday Island that Gymnothorax polyuranodon, commonly called Freshwater Moray, is unique among Morays due to the fact that the adults of this species inhabit freshwaters and low salinity environments all year round.

Originally described from Indonesia, G. polyuranodon has been reported from countries bordering the tropical Indo-Pacific, from Indonesia to Fiji, including the wet tropics of Australia.

Gymnothorax polyuranodon was first recorded from Sri Lanka by P.E.P. Deraniyagala in 1937 from Kahangama and Dodangoda.

“There have been no other records of this species from Sri Lanka ever since.

In 2021, a photograph depicting a moray eel caught at Wakwella by a fisherman was forwarded to one of the authors (TR) for identification,” he said.

A sample of gill tissue was obtained from the dead specimen for DNA barcoding and this genetic sequence was well matched with other Gymnothorax polyuranodon genetic sequences confirming the identity of the recently discovered specimen from Sri Lanka.

Gymnothorax polyuranodon is one of the most elusive freshwater fishes in Sri Lanka and more research needs to be done to figure out the ecology, life history and the distribution of this enigmatic species in Sri Lanka. “