The taxonomic identity and distribution of the eel cod Muraenolepis (Gadiformes: Muraenolepididae) around South Georgia and the South Sandwich Islands

摘要

Fishes of the genus Muraenolepis are regularly caught in commercial and research fishing in the waters around South Georgia and the South Sandwich Islands, but for many years there has been uncertainty about the specific identity of the species being caught. Here, we used morphological and molecular data to clarify the identity of specimens of Muraenolepis caught in trawl surveys and longline fisheries in South Georgia and South Sandwich Island waters. Type specimens of M. marmorata, M. microps and M. orangiensis were examined, together with specimens caught in trawl surveys around South Georgia. Morphological and molecular (mitochondrial 16S and cox1 sequence) data from specimens collected throughout the Southern Ocean indicate four clades and confirm the presence of just one species (M. marmorata) on the South Georgia continental shelf. The data also confirm that M. microps is a junior synonym of M. marmorata, which has a broad distribution around sub-Antarctic islands in the Southern Ocean extending as far south as the South Orkneys and the southern South Sandwich Islands. Muraenolepis evseenkoi is the main species caught in longline fisheries in the South Sandwich Islands and, with a more southerly distribution, is not known from around South Georgia. A third species (M. kuderskii) is also reported from around South Georgia and one specimen was considered to belong to this species. In total, there are eight recognised species of muraenolepidids in two genera, with six species having an Antarctic distribution.