Deep-sea Tanaidacea (Crustacea) of the North-east Atlantic: the genus Paranarthrura Hansen

The tanaidacean genus Paranarthrura is represented in the North-east Atlantic by seven species, four of them new. This genus is transferred to the tribe Agathotanaini from the Anarthrurini because of its very close morphological affinities with the genera Agathotanais, Paragathotanais and Metagathotanais, and the identical configuration of the males. The genus Allodaposia is also transferred, but this has not been recorded in the study area. There are differences in the cheliped-cephalothorax articulation within Paranarthrura which may prove to be of critical phylogenetic value. Species of this genus were recorded from 463–4829 m, the shallowest and deepest depths inhabited by Paranarthrura crassa sp. nov. and P. tridens sp. nov. respectively. Paranarthrura borealis, P. lusitanus sp. nov. and P. borealis sp. nov. are stenobathic bathyal species, while P. insignis and P. intermedia are more eurybathic and extend into the abyssal zone. None is as abundant as Agathotanais ingolfi. A key is provided for the i...