Width/length–weight relationships and condition factor of seven decapod crustaceans in a Brazilian tropical estuary

Abstract

The analysis of body relationships and condition factors are useful tools in studies of marine populations, and they have been widely used in fishery research and management. In this study, width–weight (WWR) and length–weight (LWR) relationships and Fulton’s condition factors were analyzed for six commercially important decapod crustacean species from the Paraguaçu River estuary (Todos os Santos Bay), eastern Brazil, namely Callinectes danae, C. exasperatus, C. marginatus, C. ornatus, Goniopsis cruentata and Ucides cordatus, and one non-indigenous species, Charybdis helleri. In total 5,704 individuals were measured and weighed during five years (2012–2017). The three allometric growth types for the crustacean species were observed, being most frequently the negative allometric growth. The analysis of covariance (ANCOVA) revealed significant differences between the sexes and climatic seasons in WWR/LWRs for the four species of the genus Callinectes, C. helleri, G. cruentata and U. cordatus, except for females and males of C. danae in WWR. The means for condition factor were generally higher for females than for males during the dry period, and in general, indicating good conditions for crustacean species. This study provided morpho-biometric parameters information will contribute stock management of traditional artisanal fisheries, and enable future comparative studies of populations of the same species.