American parasite infects Japanese snakes

Scientists have discovered an American parasitic worm infecting Japanese snakes. An American snail, Physella acuta, likely brought the trematode, Ochetosoma elongatum,to Japan via imported freshwater aquarium plants. The other possibility is that an American snake introduced the parasite through the pet trade. Parasites from the Ochetosomatidae family are found throughout North America. They typically infect snakes in the final stage of their development, which starts with snails then likely jumps to frogs as intermediate hosts. “Ochetosoma elongatum was frequently found in the lungs and oral cavities of Japanese host snakes in the Kanto region,” the authors of the study published in Parasitology International wrote. Infected species of snakes include the Japanese striped snake (Elaphe quadrivirgata), the Japanese rat snake (E. climacophora) and the tiger keelback (Rhabdophis tigrinus). While the symptoms in these snakes are unclear, the trematodes can cause inflammation in the mouth and lips in snakes found in the Americas such as the fer-de-lance (Bothrops asper). This trematode isn’t the first American invader in Japan—researchers also reported a related species, (O. kansense) infecting snakesin western Japan.

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