Geographical distribution of Ozobranchus jantseanus (Annelida: Hirudinida: Ozobranchidae) in Japan

Abstract

The geographical distribution of the ozobranchid leech Ozobranchus jantseanus, a parasite of freshwater turtles, was investigated via field surveys in Honshu, Shikoku, and Kyushu, Japan. As a result, new distributional records were found in Honshu (south of Ishikawa Pref.) and northern Shikoku. The host species of O. jantseanus were the Reeve's pond turtle Chinemys reevesii and the Japanese pond turtle Mauremys japonica. Most of the leeches were found in the folds of soft tissue between the carapace and the plastron of the turtles. Some of them were found in the orbital cavity or on the carapace. Moreover, clumps of their eggs were often observed attached to the carapace.