Bioaccumulation of total mercury (THg) in catfish (Siluriformes, Ariidae) with different sexual maturity from Cananéia-Iguape estuary, SP, Brazil

Abstract

In order to improve the knowledge of total mercury (THg) bioaccumulation in bioindicator species of sea catfish (Siluriformes, Ariidae) and taking into account the relatively recent approach with respect to estuarine fish on the Brazilian coast, 65 individuals were caught in the northern and southern regions of the Cananeia estuary to determine the concentration of the THg in muscles, gills, gonads and kidney of the Cathorops spixii and Genidens genidens specimens. The difference in the THg accumulation associated to the maturity of the catfish reflects a differential metabolism regarding THg bioaccumulation in adults (males and females) and juveniles. These observations reinforce the importance of considering the maturity of the individual in order to understand the bioaccumulation and metabolism of fish under different environmental stress and conditions. Furthermore, abiotic conditions such as salinity should be evaluated in association with metabolic/biological conditions of the fish’s bioindicators, especially in environments with large natural or anthropogenic transition gradients.