ABSTRACT
The genus Metagonimus was established with M. yokogawai as the type species, 1–3 and eight more species have so far been described (Table 71.1): M. ovatus Yokogawa, 1913 4 ; M. takahashii Suzuki, 1930 5 ; M. minutus Katsuta, 1932 6 ; M. katsuradai Izumi, 1935 7 ; M. otsurui Saito and Shimizu, 1968 8 ; M. miyatai Saito et al., 1997 9 ; M. hakubaensis Shimazu, 1999 10 ; and M. suifunensis Shumenko et al., 2017. 11 In 1920, M. ovatus was synonymized with M. yokogawai by Ransom. 12 Thereafter, Morozov 13 in 1952 and Yamaguti 14 in 1958 did not list M. ovatus as a distinct species. However, its validity was acknowledged by Shimazu and Kino 15 in 2015 in consideration that the shorter termination of intestinal ceca of M. ovatus (ending in the anterior half of the testicular zone) compared with that of M. yokogawai (entering into the posttesticular zone) is a significantly distinct character.
