First recorded occurrence of Cheirocratus robustus Sars, 1894 in the British Isles

Background: Collections of the amphipod genus Cheirocratus from the North Sea and Ireland proved to include C. robustus Sars a species previously known only from Norway and Sweden. Results: Material of C.robustus is described and figured from the Humber and Ireland together with the closely related species C. sundevalli (Rathke). A key to males of the Cheirocratus species of the North East Atlantic and Mediterranean is provided. Conclusions: C. robustus is shown to be widespread in the eastern North Atlantic where it was previously overlooked.