A new species of Zeuxo (Crustacea: Tanaidacea) from the French Atlantic coast

A new species of tanaidacean of the genus Zeuxo is described from 105 specimens dredged from the shallow inshore benthic marine fauna from Arcachon, western France. This is the only species of Zeuxo in the Lusitanian area. Its combination of a 7-articled uropod (6-articled endopod with elongate articles in the adult) with a conspicuous lacinia mobilis on the right mandible is unique for the genus. The spination and setation of the carpus of pereopod 2 is reduced in comparison with the most similar known species of Zeuxo. It is distinct from potentially sympatric species of the family Tanaidae in having five free pleonites without a dorsal fringe of setae.