Environmental variables influencing the Callinectes (Crustacea: Brachyura: Portunidae) species distribution in a tropical estuary—Cachoeira River (Bahia, Brazil)

Abstract

The genus Callinectes comprises seven species of blue crab found on the Brazilian coast, almost all are recorded in Cachoeira River estuary. The objective of this study is to analyse distribution of Callinectes species in the estuary of Cachoeira River (Ilhéus, Bahia). Monthly collections were conducted in the low tide of neap tide for a year and in five stations distributed according to the estuary salinity gradient. Six traps were assembled and submerged at each station for two hours. Sediment samples were collected for granulometric characterization and measuring of organic matter content. Temperature, salinity and pH were also measured in the bottom water, as well as water transparency at the start of each collection. Five species were collected: Callinectes danae, C. ornatus, C. exasperatus, C. larvatus and C. bocourti. The species presented different distribution patterns based on the salinity gradient and transversal profile of the estuary. Only C. danae was found in all collection points, and was the most abundant species throughout the study period. Callinectes ornatus was restricted to external estuarine areas, which presented higher salinity and transparency values. Callinectes larvatus predominantly occurred in the external station and estuary partitions, mainly in the margin. In spite of the occurrence of C. exasperatus throughout the entire estuary, this species was restricted to the margin. This study supports the assumption that species distribution patterns of this genus are the result of both variable influence, namely salinity, and complex intraspecific and interspecific relations between the congeneric species.

Abundance and distribution of the swimming crabCallinectes danaeSmith, 1869 (Crustacea, Decapoda, Portunidae) in the Ubatuba region, southeastern Brazil

“…However, Buchanan & Stoner (1988) suggested that the distribution pattern of Callinectes species is also the result of complex intra-or interspecific interactions among other congener species. Fransozo et al (1992), McClintock et al (1993), Negreiros-Fransozo & Fransozo (1995 and Carvalho & Couto (2011) studied biological aspects related to the distribution, abundance, habitat and migration of Callinectes species on the Atlantic coast, and verified that the juveniles of the majority of the species inhabit estuaries, whereas mature females conserve energy in low-salinity environments to spawn before subsequently migrating with a welldeveloped egg mass to more saline waters, offshore, where the larvae hatch.…”

Maturidade sexual em Callinectes ornatus Ordway, 1863 (crustacea: decapoda: portunidae) no litoral de Ilhéus, BA, Brasil

“…Callinectes ornatus ocorre desde a Carolina do Norte (EUA) até o Rio Grande do Sul (Brasil), em fundos de areia, lama ou conchas, em áreas estuarinas com maior salinidade, do entre-marés até 75 m de profundidade (Melo, 1996;Carvalho & Couto, 2011).…”

Infestation by the epibiont Octolasmis lowei in a portunid crab assemblage from a subtropical coast

“…found that A. cribrarius presented a lower prevalence of infestation by O. lowei and other epibionts during winter. Since the relative contribution of each demographic category (males, non-ovigerous females, ovigerous females and juveniles) to the population of a crab species often varies temporally (Santos et al, 1995;Johnson and Perry, 1999;Carvalho and Couto, 2011;Andrade et al, 2013), these categories might have been represented differently in our sample when compared to those of previous studies, which may explain some divergences in results (e.g. infestation on ovigerous females tend to be higher than non-ovigerous females and males, probably because these females has longer intermolt periods; Costa et al, 2010).…”