LARVAL AND EARLY POSTLARVAL DEVELOPMENT OF LEPIDOPA BENEDICTI SCHMITT, 1935 (ANOMURA: ALBUNEIDAE) REARED IN THE LABORATORY

Abstract

The complete larval development of an Atlantic Lepidopa from a known parental female is described for the first time. The ovigerous L. benedicti was collected at Horn Island, Mississippi (Gulf of Mexico). The larval development consisted of 4 zoeal stages, and one megalopal stage which was reached 14-17 days after hatching, at 25?C and 26%0 salinity. Zoeae of L. benedicti are very similar to those of other known Atlantic Lepidopa; there are differences among the corresponding zoeal stages in abdominal spination, and in zoeae II and III, differences in setation of the antennule and exopods of maxillipeds 1 and 2. The megalopa of L. benedicti is compared with other known megalopae of Lepidopa, 1 from the Atlantic and 2 from the Pacific. All megalopae are separable using setation of the antennular ventral flagellum, and the megalopa of L. benedicti can also be separated from the other Atlantic species by segmentation of the antennular dorsal flagellum. The development of selected adult key characters of L. benedicti (carapace frontal margin, eyeshape and pigmentation, posterior dorsal carapace groove, and pereiopod 2 dactylus shape) is illustrated and described through crab 4. In crab 4, all selected characters became diagnostic except for the pereiopod 2 dactylus which has not yet attained adult shape. Abele and Efford (1971) and Efford (1971) recognized 17 species of sand crabs, genus Lepidopa, from both coasts of the Americas and adjacent islands, including six species from the western Atlantic. Lepidopa benedicti Schmitt, 1935, and L. websteri Benedict, 1903, are the only western Atlantic species known from the nearshore waters of the southeastern United States (Efford, 1971). In the Gulf of Mexico, these species are sympatric at least from Grand Isle, Louisiana, to Petit Bois Island, Mississippi (Efford, 1971; Felder, 1973). In the Atlantic, L. benedicti is reported only as far north as central eastern Florida (Gore and Van Dover, 1980) and L. websteri only as far south as Sapelo Island, Georgia (Kurata, 1970; Williams, 1984). The four other western Atlantic species, L. dexterae Abele and Efford, 1971, L. distincta Gomes, 1968, L. richmondi Benedict, 1903, and L. venusta Stimpson, 1860, are known as adults only from the Caribbean coast of Panama, the eastern Antilles, and the eastern coast of South America (Abele and Efford, 1971; Efford, 1971; Gore and Van Dover, 1980). Information on the larval development of species of Lepidopa is scanty. Johnson and Lewis (1942) described zoea I, and Knight (1970) the entire zoeal series and megalopa from laboratory-hatched eggs of females attributed to L. myops Stimpson, 1860. Based on Efford's (1971) revision of Lepidopa, Johnson and Lewis (1942) and Knight (1970) actually described developmental stages of L. californica Efford, 1971 (Sandifer and Van Engle, 1972). Knight (1970) also described four zoeal stages of an unidentified species, and Sanchez and Aguilar (1975) described the entire zoeal development and the megalopa of L. chilensis Lenz, 1902, from laboratory-reared larvae. In the Atlantic, Kurata (1970) partially described zoea I of L. websteri hatched in the laboratory, and three other zoeal stages and the megalopa (from plankton samples) that he assumed were L. websteri. Sandifer and Van Engle (1972) described zoeae I-III of putative L. websteri from plankton samples taken in Virginia waters. At that time L. websteri was not known as an