Redescription of Hydrolagus africanus (Gilchrist, 1922) (Chimaeriformes: Chimaeridae), with a review of southern African chimaeroids and a key to their identification

Abstract

Hydrolagus africanus (Gilchrist, 1922) is a little-known chimaeroid species, originally described from the KwaZulu- Natal coast of South Africa, with a range spanning the western Indian Ocean from Kenya, south to  Mozambique and South Africa, and extending into the south-eastern Atlantic to Namibia. This species is characterised by a lateral patch of denticles on the male prepelvic tenacula, a second dorsal fin slightly indented in the centre, a long, curved dorsal spine equal to or sometimes exceeding the height of the first dorsal fin, and a uniform light brown body with no distinctive markings or patterns and slightly darker brown fins. To clarify the taxonomic status of H. africanus, we examined and compared specimens from throughout its range in southern Africa. Because the syntypes of H. africanus are lost, we designate a neotype and redescribe the species based on the neotype and additional southern African specimens. In addition, we present a review of southern African chimaeroids and provide an updated key to their identification.

Keywords: African chimaera, conservation, endemic, morphology, neotype, taxonomy