Biochemical and physiological biomarkers in Prochilodus lineatus submitted to in situ tests in an urban stream in southern Brazil.

The aims of the present study were to verify the suitability of short-term in situ test with the neotropical fish Prochilodus lineatus and to evaluate from a set of biochemical and physiological biomarkers the ones which could work as sensitivity tools for the environmental quality assessment. In situ tests were carried out for 1 week in winter and summer, at three sites along an urban stream heavily contaminated by anthropogenic activities and at a reference site. The variables analyzed were: hemoglobin content (Hb), plasma concentrations of cortisol, glucose, total protein, Na(+) and Cl(-), plasma osmolarity, liver activities of glutathione-S-transferase (GST) and catalase and interrenal cells area. Results showed that glycemia, interrenal cell size and GST activity, which were significantly higher in fish caged in the urban stream, were best able to distinguish between the most disturbed sites and the reference and caged P. lineatus showed to be a promising tool for the assessment and monitoring of tropical aquatic ecosystems.