Identity and redescription of Congromuraena musteliceps Alcock, 1894 (Anguilliformes: Congridae)

The taxonomic identity of Congromuraena musteliceps Alcock, 1894 has remained unresolved for more than a century, with the species having been placed in four different genera. For much of this time it was accommodated under Gnathophis Kaup, 1859, although Smith et al. (2017) noted similarities with Japonoconger Asano, 1958 and suggested that its generic placement required further study. During recent deep-sea trawl surveys along the west coast of India, a large number of specimens referable to G. musteliceps were collected. Detailed morphological examination, combined with molecular analyses of mitochondrial CO1 sequences, demonstrated that G. musteliceps is more closely related to Japonoconger than to Gnathophis or other genera of Congridae. Herein, we redescribe the species based on type material and newly collected specimens and comparisons are made with the closest genera of the subfamily Congrinae and confirming its generic affinity with Japonoconger.