Abstract
A survey for detection of Paragonimus iloktsuenensis and Paragonimus ohirai metacercariae from the brackish water crab, Sesarma dehaani, was carried out at 14 sites about 6-10 Km upstream of the estuaries of the Ibi, Nagara and Kiso rivers flowing into the Ise Bay in central Japan in 1988. P. iloktsuenensis metacercariae were found from crabs collected from 12 sites, no metacercariae being detected at the two sites of uppermost stream along the Ise and Kiso rivers, respectively. The infection rates were as low as 2.6-42.5%, the average infection rate being 13.9%. The number of P. iloktsuenensis metacercariae per P. iloktsuenensis positive crab ranged from 1 to 10, the average number being 1.7. In contrast, P. ohirai metaceracriae were found from all the sites and the infection rates varied between 22.6% and 97.5%. The number of P. ohirai metacercariae per P. ohirai positive crabe ranged from 1 to 415, the average number being 20.8. There was a general trend in the survey area that P. iloktsuenensis metaceraciae were found were P. ohirai infection rates were higher. This is the first record that P. iloktsuenensis metacercariae were found from crabs in these three rivers in Aichi and Mie Prefecture of central Japan.

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Key words: lung fluke; Paragonimus iloktsuenensis; Paragonimus ohirai; general distribution.

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