Dichelyne japonicus sp n. (Nematoda: Cucullanidae), a new intestinal parasite of the marine sciaenid fish Argyrosomus argentatus in Japan

A new cucullanid nematode, Dichelyne iaponicus sp. n., is described from a single available specimen collected from the intestine of the marine fish Argyrosomus argentatus (Houttuyni) (Sciaenidae, Perciformes) from the East China Sea in Japan (Shimabara, Nagasaki Prefecture, Kyushu Island). This species is characterized by the absence of a ventral sucker (subgenus Dichelyne) and it differs from its congeners mainly in possessing a bifurcated tail tip, two unequally long intestinal caeca, equal spicules 0.088 mm long, and in a distribution of caudal papillae. This is the first Dichelyne species reported from Japanese waters.