Six early third-stage larvae of Gnathostoma nipponicum were recovered from the muscle of 376 loaches, Misgurnus anguillicaudatus, imported from China. They were 614 x 114 microns in average size, almost colorless except brownish intestine, and encircled by about 229 transverse rows of minute cuticular spines. Their head bulbs provided with 3 rows of hooklets, of which average number were 34.5 on the first, 36.7 on the second and 39.7 on the third. Accordingly, it is revealed that the Chinese loach is a natural second intermediate host of G. nipponicum and G. nipponicum has been distributed somewhere in China. This parasite may infect human when the imported loaches are consumed raw.
