Physiological biomarkers in a resident and a non-resident estuarine teleosts species: a comparison between fish from an industrially impacted site and a non-impacted site

Abstract

Physiological biomarkers were compared in two estuarine fishes: an estuarine resident (Atherinella brasiliensis) and a marine/estuarine transient (Sphoeroides testudineus). These fish were sampled from two estuarine systems: one with an active harbor (impacted site), and another which receives mostly domestic urban runoffs and is much less impacted (reference site). The resident fish displayed higher plasma osmolality and sodium (1.13 and 1.35-fold, respectively), and the transient fish displayed higher plasma osmolality (1.05-fold), potassium (1.17-fold), and magnesium levels (1.84-fold) in the impacted site, when compared to the reference site. The resident fish showed increased renal carbonic anhydrase activity and branchial expression of HSP70 (3.3-fold) in the impacted site, when compared to the reference site. Osmoregulatory parameters and HSP70 expression are strong candidates as physiological biomarkers for environmental assessment of industrial impact on estuarine teleost fishes.

Keywords:

• carbonic anhydrase
• estuaries
• fish
• HSP70
• osmoregulation
• pollution

Acknowledgements

The authors wish to acknowledge the immense help from Dr Jean R.S. Vitule of the Department of Environmental Engineering of the Federal University of Paraná (UFPR) in collecting the fishes, and IAP for fish facilities (boat and housing for fish sampling activities). This study has been financed by CNPq (Post-doctorate fellowship to VP), and DAAD-German Academic Exchange Service (donation of laboratory equipment to CAF). This study has been certified (#255) by the Ethics Committee for Animal Experimentation (EAEC) from UFPR.