Larvae of the Hermit Crab, Pagurus arcuatus , From the Plankton (Crustacea, Decapoda)

Abstract

Four Zoeal Stages and the megalopa of the hermit crab, Pagurus arcuatus, Squires, 1964, are described from the plankton and compared with P. acadianus Benedict, 1901, the only other species present in a small inshore area in Bonavista Bay, Newfoundland. Pagurus arcuatus has longer exopods than endopods of antennae in Zoeal Stages I–III, few setae on scaphognathite and medial accessory spine on inner spine of uropodal exopod in Zoea Stage IV, and in the megalopa no median posterior spine on abdominal somite 6 and no postero-lateral spurs on the telson. It has a low posterolateral spine on each side of the soft part of the carapace, also 8 setae at the posterior edge of telson. All these are different from P. acadianus.