We are introducing a new section that will appear weekly in collaboration with the Chunichi Shimbun featuring topics and issues from the Chubu region covered by the newspaper.

A growing number of U.S.-born alligator snappers, which can grow in excess of 100 kg and inflict serious bites, are being abandoned by pet owners in the Chubu region.

Listed in the United States as an endangered species due to overhunting, an Aichi Prefecture ecology expert said the reptiles deserve care.

"Humans are to blame, not the turtles, since they irresponsibly abandoned them," said Takashi Yabe, professor of animal bionomics at Aichi Gakusen University. Yabe has 14 abandoned alligator snappers in his laboratory.

Japan calls the turtle "wanigame," and has designated them as a dangerous alien species under the Invasive Alien Species Act. Warning signs are posted along rivers and ponds about the "nuisance."

Alligator snapper meat used to be popular in the U.S. because it did not have a gamy taste and one tortoise could provide plenty of meat. After their numbers drastically declined in the 1980s due to overhunting, the International Union for Conservation of Nature and Natural Resources (IUCN) listed the turtle as a threatened species.

"Look, isn't he cute?" asked Yabe, known as "Dr. Turtle," as a gator snapper thrashed about in a tank at his lab.

Reptiles, including the snappers, became popular pets in Japan in the booming late 1980s. One U.S. study suggests tens of thousands of alligator snappers were taken to Japan.

Experts say alligator snappers can live a century, and their weight can exceed 100 kg. "It costs a lot to feed them, and pet owners sometimes die before the turtle does. Because of that, snappers are not suitable as pets."

Discarded alligator snappers also pose a threat to native species, including crucian carp and other turtles.

So far there have been no alligator snapper births reported in Japan. But if crossbreeding were to occur, it would be considered very gene-disruptive and the alien species would be targeted for destruction.

"I'll do my best to send them back to where they came from. It should be possible to identify each turtle's original habitat by checking DNA," Yabe said.