The larval development of the hermit crabAreopaguristes nigroapiculus(Decapoda: Anomura: Diogenidae) reared under laboratory conditions
The larval development of the hermit crabAreopaguristes nigroapiculus(Komai, 2009) (Decapoda: Anomura: Diogenidae) is described and illustrated from the material reared in the laboratory. The development included three zoeal and a single megalopal stages. At 22–25°C, megalop ofA. nigroapiculuswas attained 6–9 days after hatching. The present paper is the first description of the complete larval development in the genusAreopaguristes. Morphological characters of zoeas and megalop ofA. nigroapiculusare compared with those described for the closely relatedPaguristesspecies. The comparison on the zoeal characters revealed thatA. nigroapiculusis distinguished fromPaguristesspecies by the absence of anterolateral carapace spines and by the fused fourth telson process in zoea III. These two features are possible generic characters ofAreopaguristes. In the rest of larval characters,A. nigroapiculusagree well withPaguristesspecies having three zoeal stages. In the plankton of Peter the Great Bay, the larvae ofA. nigroapiculussporadically occurred only in July and August, at depths of 3–45 m and surface water temperatures of 18–22°C.