Relações morfológicas e morfométricas dos camarões rosa Farfantepenaeus Burukovsky, 1997 (Decapoda, Penaeidae) em simpatria no Nordeste do Brasil

Abstract

The genus Farfantepenaeus is one of the most exploited fisheries resources in the world. The genus is composed by nine species, including the recently described F. isabelae, presented as a cryptic species with F. subtilis. There are evidences of the occurrence of both species in the coast of Rio Grande do Norte State, Brazil, where they would coexist sympatrically with F. brasiliensis. The great similarity between the species of the genus, the lack of identification keys that contemplate the juvenile stage, and the need for new approaches to search for new characters to better distinguish them, are remarkable. Thus, this study proposes the characterization of the secondary sexual characters through ontogeny and the evaluation of allometry of these characters in relation to of the cephalothorax for F. subtilis and F. brasiliensis. A quantitative evaluation of adrostral groove; a morphological analysis, including scanning electron microscopy, in the search for new characters to a better identification and differentiation between F. subtilis, F. brasiliensis and F. isabelae. The samples were collected on the north and east coast of the state. Identification of the specimens was confirmed by molecular analysis. A specific quantitative pattern was defined for the groove of each of the three species. New and effective diagnostic characters were defined to distinguish them, from the juvenile stage, for both sexes in for F. subtilis and F. brasiliensis, with highlighting to the found differences between F. subtilis and F. isabelae; positive allometry was reported for Carapace Length vs Petasma Length ratios (males), Carapace Length vs Height of side plates and Carapace Length vs Width of side plates (females). The results presented, serve as basis to future studies of systematics, evolution and ecology, among species of the genus.