Chondracanthid copepods (Poecilostomatoida) parasitic on Japanese deep-sea fishes,with a key to the genera of the Chondracanthidae

Four species of chondracanthid copepods are reported from grenadier fishes (Macrouridae) taken in the deep waters off Japan. They are Chondracanthus neali Leigh-Sharpe, 1930 from the oral cavity floor of Malacocephalus nippoensis Gilbert et Hubbs; Chondracanthodes deflexus Wilson, 1932 from the gill cover of Coryphaenoides armatus (Hector); Jusheyhoea ryukyuensis sp. nov. from the oral cavity wall of Coelorhynchus anatirostris Jordan et Gilbert, C. gilberti Jordan et Hubbs and C. productus Gilbert et Hubbs; and Chelonichondria okamurai gen. et sp. nov. from the gill cover of Coryphaenoides nasutus Günther. A key to the 42 genera of the Chondracanthidae is provided.