Coelorinchus posteromaculatus (Actinopterygii, Gadiformes, Macrouridae), a new species of grenadier from the eastern Indian Ocean

Abstract

A new species of grenadier, Coelorinchus posteromaculatus, is described from nine specimens collected from the tropical eastern Indian Ocean at depths of 100–323 m. This species belongs to the Coelorinchus argentatus group (defined here to include 13 species), but differs from other members of that group in its unique body markings consisting of a single, prominent, lateral, dark blotch on the anterior part of the tail, and a slightly diagonal, narrow, dark stripe extending from the upper margin of the gill opening to below the first dorsal-fin midbase or beyond. Coelorinchus posteromaculatus is most similar to C. gaesorhynchus Iwamoto and Williams 1999 and C. longissimus Matsubara 1943, but further differs from the former in its much shorter snout (74–91% of postrostral length vs. 93–100% in C. gaesorhynchus), and from the latter in its relatively small mouth (upper-jaw length 38–43% of postrostral length vs. 42–49%).