RESUMO
Recent occasional examinations of two species of eels (Anguilliformes: Anguillidae) in Japan, the Japanese eel Anguilla japonica Temminck & Schlegel from central Japan and the giant mottled eel Anguilla marmorata Quoy & Gaimard from southern Japan, respectively, revealed the following four species of gastrointestinal parasitic nematodes: Cucullanus filiformis Yamaguti, 1935 (Cucullanidae) from A. japonica; Paraquimperia japonica n. sp. (Quimperiidae) from A. japonica (type-host) and A. marmorata; Heliconema anguillae Yamaguti, 1935 (Physalopteridae) from A. marmorata (new host record); and Spinitectus anguillae n. sp. (Cystidicolidae) from A. japonica (type-host) and A. marmorata. Specimens of all species are described based on light and scanning electron microscopical examinations. Paraquimperia japonica n. sp. is mainly characterised by the presence of a ventral sucker, spicules 210-231 µm long and by narrow cervical alae, whereas S. anguillae n. sp. by the number (29-36) of cuticular spines in the first ring, the length of the left spicule (351 µm) and the structure (without polar caps, filaments or lateral swellings), and the size of eggs (36-42 × 21-27 µm).
