In Japanese rivers, if you’re very lucky, you might find unusual amphibians that grow up to 5 feet long and look like strange cartoon dinosaurs. They are giant salamanders.

"Salamanders are big, and they’re cool,” said Sena Ishikawa, a master’s student studying the animals at Kyoto University. "I just love them.”

Such passion for the slippery species, which Japan has designated a "special national treasure,” prompted Ishikawa and two other students to set out on an unseasonably cold evening in March along the Kamo River in Kyoto, wearing headlamps, waterproof overalls, knee-high rubber boots and neon yellow safety vests, and carrying what looked like oversize butterfly nets.