Description of a new species of Hirsutonuphis (Annelida: Onuphidae) from the Mexican Pacific, with notes on the world distribution of the genus

Abstract

A new species of Hirsutonuphis (Annelida: Onuphidae) is described from the continental shelf of the Gulf of California, Mexican Pacific. Hirsutonuphis paxtonae sp. nov. is easily distinguished from eight previously described species belonging to this genus, by the bi- and tri-dentate pseudocompound hooded falcigers on the first 5–6 chaetigers, the pectinate chaetae from chaetigers 6–11, the bidentate subacicular hooded hooks from chaetigers 18–21, and its colour pattern: a dark transverse band in the dorsal part of the peristomium and on each chaetiger, which gradually fades from chaetigers 12–27. Most species of Hirsutonuphis have been found in the Pacific Ocean, and more particularly in Australian waters, although this new onuphid is the third species of the genus described from the Mexican Pacific, in the Tropical Eastern Pacific. A taxonomic key is provided for all the species of the genus.