Description of a new species of hound shark of the genus Iago (Carcharhiniformes: Triakidae) from the northern Indian Ocean

Abstract

Sharks of the genus Iago Compagno and Springer, 1971 (Carcharhiniformes: Triakidae) that commonly occur in the deep waters of the Indo-Pacific, are an interesting group phylogenetically. Currently, three nominal species of Iago are known globally, namely, Iago garricki, I. omanensis and I. mangalorensis. In this study, we describe a new species of hound shark, Iago gopalakrishnani sp. nov. from the deep waters of eastern Arabian Sea, India. Iago gopalakrishnani sp. nov. is distinct in its dark chocolate brown to blackish colouration and low fins; pre-oral length 4.7–6% TL, 22.4-25% head length; first dorsal height 5.8-7% TL, first dorsal length 10.6–14.1% TL, first dorsal base length 6.7-9.8% TL, second dorsal length 8.9-10.9% TL and vertebral counts 117-123. Iago gopalakrishnani sp. nov. is genetically distinct from congeners. COI based analysis of Iago gopalakrishnani sp. nov formed a distinct clade in phylogenetic reconstruction with a genetic distance of 4.5-5.2% when comparing K2P parameters with congeners.