"It's really hard to weigh these things without hurting them, because they are such big, awkward animals," he said, according to National Geographic.
An ultrasound revealed that the stingray was pregnant with two fetal rays, National Geographic reports. And the same ray was caught and tagged in 2009, when she was also pregnant. Hogan said that means the area is likely a "nursery ground."
That's good news for Thailand's giant freshwater stingrays, a group listed as critically endangered by the International Union for the Conservation of Nature. Threatened by overfishing, habitat degradation and contamination from pollution and oil spills, the species has been in dire straits recently.