Limnetica 42

Colomesus asellus (Amazonian Puffer) is endemic to the Amazon Basin. It uses channels and streams to reproduce, spawn and feed. In areas close to urban centers, these fish may be exposed to anthropogenic residues containing mixtures of metals that can be bioaccumulated, resulting in genetic alterations. Therefore, we aimed to determine the extent of nuclear alterations in erythrocytes of female C. asellus resulting from the bioaccumulation of metals in tissues and organs. Metal concentrations were analyzed by atomic absorption spectrophotometry. Tissue metal concentrations decreased in the following order: Fe > Zn > Cu > Mn > Hg > Pb > Ni > Cd > Cr. In fish tissues/organs, the concentration of metals followed, in decreasing order, liver > skin > gonads > musculature > bones. The most frequent nuclear alterations were nuclear invagination, nuclear budding and lobulated nucleus. Metal concentrations and resultant nuclear alterations observed can damage C. asellus, thus compromising the conservation of this species at the mouth of the Amazon River.