Spatiotemporal Distribution of Swimming Crab Callinectes danae and Callinectes ornatus (Crustacea: Decapoda) in an Upwelling System in the Southwestern Atlantic

Knowledge about Callinectes danae and Callinectes ornatus is thorough, although scarce in different ecological regions like Macaé, which are influenced by the Cabo Frio upwelling phenomenon in the southwestern Atlantic Ocean. This study analyzes spatiotemporal variation in the abundance of two swimming crab species in a region influenced by upwelling. Samplings took place from July 2013 to June 2014, on a monthly basis, with the aid of a shrimp fishing boat, in four different sampling sites. In total, 92 C. danae specimens were captured; C. ornatus was the most abundant species over the year; 1.436 individuals were captured. Both species were the most abundant in the shallowest sites and warmest seasons. Visual trends in temperature, salinity and sediment size (Phi) were observed for both species. Phi was the only significant variable associated with the sampled swimming crabs. The results indicated similar distribution between C. danae and C. ornatus, and a clear prevalence of C. ornatus, possibly due to C. danae’s estuarine dependence on its life cycle and to C. ornatus’s generalist behavior. The abundance of both species in Macaé is modulated by a combination of spatiotemporal and environmental variation in this upwelling region.