Redescription of Luetkenia elongata (Copepoda: Siphonostomatoida: Pandaridae), an ectoparasite of Luvarus imperialis (Actinopterygii: Perciformes: Luvaridae), with a new record from Japanese waters

Abstract

A rare copepod parasitic on marine fish, Luetkenia elongata Shiino, 1963 (Siphonostomatoida: Pandaridae), is redescribed based on type specimens and additional specimens obtained from Luvarus imperialis Rafinesque, 1810 caught in the eastern and western North Pacific Ocean off California and Japan, respectively. This represents the first record of this parasite from Japanese waters. The copepod differs from its sole congener, L. Asterodermi Claus, 1864, by following features of the female: fourth pedigerous somite with one pair of elongate posterolateral lobes; genital complex bearing a pair of well-developed posterolateral lobes with one conical protuberance on lateral corner; abdomen clearly longer than wide; and caudal rami more than 2.0 times longer than wide.