Taxonomic notes on the rare deep-sea crab Nectopanope rhodobaphes Wood-Mason in Wood-Mason & Alcock, 1891 (Brachyura, Euryplacidae) from the Bay of Bengal, India

Abstract The deep-water euryplacid crab, Nectopanope rhodobaphes Wood-Mason in Wood-Mason & Alcock, 1891, is monotypic and was originally described from one female from the Bay of Bengal, 18°30′N 84°46′E, a location off the coast of Andhra Pradesh in India. This species has only been reported subsequently by Ng et al. (2019) from a first male specimen collected in southern India. Recent collections of N. rhodobaphes from off Tamil Nadu in India obtained good series of male and female specimens. The study of these specimens revealed a degree of size-associated variations in the structures of the anterolateral teeth, as well as branchial regions of the carapace and first male gonopods. Scanning Electron Microscopy was used to record the microstructures associated with the female sternum, gonopods and vulva. Also, recorded is its live colouration. The swollen branchial regions of this species are not due to parasitism but shown to be natural and could indicate it may occur in oxygen poor areas of the deep-sea.