Zoeal development of Ethusa microphthalma smith, 1881 (Brachyura,Dorippidae) reared in the laboratory,with a comparison of other dorippid zoeae

The complete zoeal development of a dorippid crab in the subfamily Ethusinae is described for the first time from a known parental female. The ovigerous Ethusa microphthalma was collected in the northern Gulf of Mexico off Louisiana. Larvae passed through four zoeal stages, and the megalopa was reached in 59 days at 20°C and 35 ppt salinity. The larvae differ from those of the few other dorippids for which a zoea is known. Salient distinguishing features include long lateral carapace spines, the presence of six setae on the endopod of the maxillule and maxilla, and a spinose antennal exopod lacking projecting mid-length spines or setae. Zoeal characters are compared to those known for the allied subfamily Dorippinae, and all references to zoeae of the Dorippidae are tabulated.