Comparative analysis of the early larval stages of two marine shrimp genera Leander and Nematopalaemon (CARIDEA, PALAEMONIDAE) obtained in the laboratory

The first and second zoeal stages of Leander paulensis and Nematopalaemon schmitti are described and illustrated from laboratory-reared material. These descriptions constitute the first larval description for both species. Larvae were obtained from females with embryos collected in tropical locations of Brazil's southeast coast (L. paulensis at Cananeia, Sao Paulo state, and N. schmitti at Macae, Rio de Janeiro state). The morphology of newly hatched larva is compared with previous descriptions of congeners (L. tenuicornis and N. tenuipes). Obvious similarities were observed between the genera (carapace spines; peduncle and flagella of antenulle; flagellum of antenna; endopods of maxilla; pereiopods; and telson formula). However, a considerable number of morphological differences are pointed to distinguish these two genera, and even the species into them. The information provided here will help the identification of these species in plankton samples and can be used in future studies of life histories and phylogenetic relationships at different taxonomic levels.