Larval and early juvenile stages of Pirimela denticulata (Montagu, 1808) (Crustacea, Brachyura, Pirimelidae) reared in the laboratory

Abstract

Former larval descriptions of Pirimela denticulata are incomplete and do not include information on appendage setation among other important data. Plankton-caught material provided further morphological data, but complete descriptions of larval stages were still lacking. In this study, the four zoeal stages and the megalop are fully described, and the general morphology of early crab stages is examined. Comparing the zoeal appendage setation suggests that P. denticulata is closely related to carcinine portunids, as previous studies based on gross zoeal morphology had once indicated. The megalop of P. denticulata is very similar to those of Necora puber, Carcinus maenas and C. mediterraneus but both setation of appendages and the presence or absence of coxal spines on walking legs may be used to distinguish these species. First and second juvenile stages can be readily identified to species but genital openings are still not visible, making impossible sex determination at this stage.