Chionodraco

Chionodraco was first described as a genus in 1905 by the Swedish zoologist Einar Lönnberg when he described the Chaenichthys hamatus which he subsequently placed in a new monotypic genus.^[1] The genus name is a compound of chionos meaning "snow" and draco which means "dragon", Lönnberg did not explain this but it may allude to a relationship with the genus Cryodraco.^[2]

There are currently three recognized species in this genus:^[3]

• Chionodraco hamatus (Lönnberg, 1905)
• Chionodraco myersi H. H. DeWitt & J. C. Tyler, 1960 (Myers's icefish)
• Chionodraco rastrospinosus H. H. DeWitt & Hureau, 1979 (Ocellated icefish)

Chionodraco icefishes may have the spine on the snout present or it is reduced to a small centrally placed knob. The gill rakers may bear teeth or are vestigial. The upper and lower jaws are of equal length, although the lower jaw may protrude. There are robust spines on the operculum with the other opercular bones each having a pair of spines where they join. The first and second dorsal fins are separate and there are three lateral lines. In the pelvic fin the outermost pair of fin rays are the longest and the tips are covered in thickened skin. The caudal fin is rounded.^[4] The maximum total length of these fishes varies from 38 cm (15 in) in C. myersi to 52 cm (20 in) in C. rastrospinosus.^[3]

Chionodraco contains two circum-antarctic species, one of which is apparently confined to West Antarctica.^[4] They are demersal and pelagic fishes found on the continental shelf and slope.^[3]