On the prezoeal stage: observations on three Pagurus species (Decapoda,Anomura)

Observation on prezoeas of three Pagurus species inhabiting the coasts of Hokkaido, P. lanuginosus de Haan, P. middendorffii Brandt, and P. brachiomastus (Thallwitz), were carried out using light and scanning electron microscopy. Hatching was produced at laboratory conditions of 17·5–18·2 °C and 32·5–33·2 ppt salinity, and after a short duration of 5–10 min, most of prezoeas moulted to the first zoeal stage. Prezoeal appendages are described and figured; previous observations on prezoeas in allied groups are summarized.