A new genus and species of rattail fish (Macrouridae) from the eastern North Atlantic and eastern Indian Ocean, with notes on its ecology

Abstract

A new genus, Macrosmia, and species (M. phalacra) of benthopelagic macrourid fish is described from single male specimens caught in 1650–1699 m soundings in the northeastern Atlantic and south‐eastern Indian Oceans. This elongate macrourine rattail, with 7 branchiostegal and 11–12 pelvic rays, is unique in its massive olfactory organ, the cavity of which almost equals the diameter of the orbit. This cavity is a reverse D‐shape, with the posterior margin deforming the orbital rim into a D‐shape. Macrosmia has a short deep snout, lacks prominent ridges on the head, has anteriorly placed plevic fins and a weakly serrated second spinuous ray in the first dorsal fin. The anus is contiguous with the anal fin. These characters, among others, show affinity with the Cetonurus group of genera. The distribution and diet of the species is briefly discussed and M. phalacra is shown to be at least partly dependent on benthic food which, from one example, is of crustacean origin.