First stage zoeal morphology of four ghost crabs Ocypode ceratophthalmus (Pallas, 1772), O. cordimanus Latreille, 1818, O. sinensis Dai, Song & Yang, 1985 and O. stimpsoni Ortmann, 1897 (Crustacea, Decapoda, Ocypodidae)

Abstract

Light and scanning electron microscopy (SEM) were used to examine the first zoeal stage of four ghost crabs, Ocypode ceratophthalmus (Pallas, 1772), O. cordimanus Latreille, 1818, O. sinensis Dai, Song & Yang, 1985 and O. stimpsoni Ortmann, 1897. Finding diagnostic characters to distinguish between the four species proved difficult because their setal appendage patterns were identical. However the rectangular and pockmarked patterns on the ventral carapace are rather pronounced in O. ceratophthalmus and O. stimpsoni but weak in O. cordimanus and O. sinensis. The spinulation on the furca of the telson is less in O. cordimanus than in the other three species.