Description and identification of the morphology of the first larval stage of the shrimps of the genus Synalpheus Spence Bate, 1888 (Decapoda, Caridea, Alpheidae) of the coast of the State of São Paulo

Abstract

The genus Synalpheus Spence Bate, 1888 is the second most abundant genus, taxonomically and ecologically diverse belonging to the family Alpheidae Rafinesque, 1815. It currently contains approximately 150 species described, of which about 60 occur in the Atlantic Ocean. In Brazil, there is the record of 26 species of this genus, of which three present an uncertain record due to innacuracies regarding to taxonomic classification, a problem that, historically, is reported for others species of the genus. Nowadays, the number of new species being described for shrimps of the family Alpheidae has increased due to new techniques used in the Decapoda systematics, generating numerous taxonomic reorganizations. Due to the inaccuracies previous reported regarding to the taxonomy of the genus Synalpheus, it is possible to state that there is a lack of relevant information to establish a solid relationship between the aspects of its biology, morphology and ecology. In order to overcome these inaccuracies, the application of larval description studies help to complement the knowledge about a taxon, elucidating its role in the life history strategies, population dynamics, and in phylogenetic and systematic studies. The genus Synalpheus currently has 15 species with at least its first larval stage described. However, for the Brazilian coast, there is no record of studies with larvae of this genus. In this way, a detailed description of these larvae contribute with information on the biology, taxonomy and systematics of the group, as well as assistance in the construction of indetification keys. (AU)