Jeff Corwin shared a photo of a 14-foot long and 8-foot wide stingray. The giant stingray might set a world record for largest freshwater fish ever captured, Corwin said on Facebook.
Reeling in the monster catch took two hours and the exertion of several men aboard the small fishing boat.
The men took turns winding the line before the ray was manoeuvred into a specially-prepared pen alongside the boat.
It then took seven men to haul the stingray out of the water so it could be measured.
The men had to calculate the weight of the fish by measuring its width, length and girth because it would be impossible to put such a large fish on a set of scales.
The catch will appear on the US TV show Ocean Mysteries With Jeff Corwin which will be broadcast by ABC later in the year.
Corwin said: “According to National Geographic, Fishsiam and Dr Nantarika Chansue – a leading stingray expert – this is likely to be the largest freshwater fish ever caught with a rod and reel.
“The battle to bring this giant fish to the boat was epic and it took many hours and multiple guys rotating off and on the reel.
“The experience was a true highlight of the series, not only connecting with a record-sized ray, but being a part of cutting edge science, going to make an unforgettable Ocean Mysteries episode.”
Rick Humphries, of Fishsiam, said: “We have caught over 450 different stingrays and our estimations have been proved highly accurate on the rare occasions we have weighed this species.
“The larger specimens are always female and quite often pregnant, as was the case with this capture.
“The latest capture indicates that these stingrays are growing at a fast and healthy rate.”