Ciguatera poisoning is a food intoxication associated with the consumption of fish or shellfish contaminated, through trophic transfer, with ciguatoxins (CTXs). In this study, we developed an experimental model to assess the trophic transfer of CTXs from herbivorous parrotfish, Chlorurus microrhinos, to carnivorous lionfish, Pterois volitans. During a 6-week period, juvenile lionfish were fed naturally contaminated parrotfish fillets at a daily dose of 0.11 or 0.035 ng CTX3C equiv. g−1, as measured by the radioligand-receptor binding assay (r-RBA) or neuroblastoma cell-based assay (CBA-N2a), respectively. During an additional 6-week depuration period, the remaining fish were fed a CTX-free diet. Using r-RBA, no CTXs were detectable in muscular tissues, whereas CTXs were measured in the livers of two out of nine fish sampled during exposure, and in four out of eight fish sampled during depuration. Timepoint pooled liver samples, as analyzed by CBA-N2a, confirmed the accumulation of CTXs in liver tissues, reaching 0.89 ng CTX3C equiv. g−1 after 41 days of exposure, followed by slow toxin elimination, with 0.37 ng CTX3C equiv. g−1 measured after the 6-week depuration. These preliminary results, which need to be pursued in adult lionfish, strengthen our knowledge on CTX transfer and kinetics along the food web.

Estuaries are coastal water bodies with great economic and biological importance. The benthic organisms play a significant role in these environments as regulators or modifiers of physical, chemical and biological processes. This study aimed to evaluate the spatial and temporal distribution of the infralittoral decapods in the Itajaí-Açu estuary, investigating factors that influence their distribution and possible effects of a flood event on the benthic community. Six sampling points were established along the longitudinal gradient of the estuary. Monthly samples were taken with otter trawls between May 2008 and July 2010. The abundance and biomass of the crustaceans were analyzed using descriptive statistics. Variations in the physicochemical data of the water column, and its possible effects over the decapods, were also evaluated. The results showed that pH, salinity and dissolved oxygen are related to the penetration of the salt wedge, while temperature shows a seasonal pattern. The estuary showed a low richness (14 species), mainly in the two months after the flood of November 2008, and high dominance. It was possible to infer that many factors act on the estuary making it difficult to establish clear relationships between the biota and environmental variables in particular. There was an increase in abundance and biomass between February and July 2009, which suggests that the fauna was able to recover from the flood.

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