Larval Development of the Mangrove Fiddler Crab (Kossmann, 1877) (Crustacea: Brachyura: Ocypodidae) Under Laboratory Conditions.

Larvae of the mangrove fiddler crab (Kossmann, 1877), hatched from an ovigerous female collected from the mangroves of Sumariat, Jazan Province, Saudi Arabia in the southern Red Sea, were reared in the laboratory. Four zoeal and a megalopal stages were recorded, and their morphological features are described herein for the first time. The setations of the cephalothoracic appendages of the zoeas of and their congeners exhibit several variations that help differentiate larvae of this genus easily from other meroplankton. However, a character of phylogenetic significance -minute spines on the forks of the telson of pleon -is common to larvae of this genus. These minute spines were studied with the aid of scanning electron microscope images. There were five common morphological features between and other fiddler crab megalope, including , and . These features were a deflexed front, rounded to obtuse frontal margin, seven-segmented antennal flagellum, unsegmented endopod of maxilla and three cincinnuli on the endopods of pleopods. Two zoeal morphological features described in this study and other studies (, the absence of lateral spines on carapace [vs. their presence in species of , and in the Ocypodinae] and the presence of a maximum of four pairs of inner setae on the telson of pleon [vs. presence of more than four pairs of setae in species of , and ]) support the taxonomic amendment of transferring spp. and spp. crabs from Gelasiminae to Ocypodinae.