Thymops takedai, a new species of deepwater lobster from the Southwest Atlantic Ocean with additional records of ‘thymopine’ lobsters (Decapoda, Nephropidae)

Abstract

A new species of deep-water clawed lobster, Thymops takedai, is described from the Scotia Sea, near South Georgia, representing the second species of the genus. The new species differs from Thymops birsteini (Zarenkov & Semenov, 1972) in having a ventrally spinose or serrated rostrum (versus smooth or finely granular), a non-flagellate maxilliped 3 exopod (versus exopod with flagellum), and a longer branchiocardiac groove that reaches to the posterior quarter of the carapace (versus slightly beyond midlength). We also report additional specimens of T. birsteini and Thymopsis nilenta Holthuis, 1974, and document considerable variation in the condition of the exopods on maxillipeds 2 and 3 of Thymopsis. This variation in the maxillipedal exopods in Thymopsis overlaps with that of Thymops, rendering the two genera otherwise almost indistinguishable apart from subtle distinctions in carapace groove patterns. Thus, the taxonomic utility of recognising both genera as separate is questionable and further study may show that the two genera should be synonymised.