Morphological and molecular evidence for a new species of the genus Raphidascaris (Nematoda: Anisakidae) from marine fishes from the South China Sea

A new anisakid nematode, Raphidascaris ( Ichthyascaris ) longispicula sp. nov., is described from the intestine and stomach of the marine fish Uroconger lepturus (Richardson) (Anguilliformes: Congridae) from the South China Sea (Guangdong and Hainan Province, respectively). The new species differs from all congeners in the subgenus Ichthyascaris by the short ventricular appendix (0.36–0.49 mm long), the number and arrangement of caudal papillae (25–28 pairs of preanal, 1–2 pairs of paranal, and 6–8 pairs of postanal), and the very long spicules (1.13–1.32 mm long, representing 9.34–10.3% of body length). The sequences of the internal transcribed spacer of ribosomal DNA of R. ( I. ) longispicula sp. nov. are analyzed and compared with the closely related nematode sequences. Molecular analyses seem to support the validity of this new nematode species based on morphological observation.