Accumulation patterns of Cd(II), Cu(II), and Cr(VI) in the gill and liver of pejerrey (Odontesthes bonariensis).

CARRIQUIRIBORDE, P.; RONCO, A.E.

Montevideo, Uruguay

Congreso; VIII Congreso SETAC Latinoamérica; 2007

Society of Environmental Toxicology and Chemistry Branch Latin-American

The time- and concentration-dependent accumulation patterns of three environmentally relevant metals, with different chemical and biological properties, were comparatively evaluated in tissue of pejerrey. Six-month-old juvenile juveniles were exposed either to 1, 5, and 10 µgCd2+/L; 10, 50, and 100 µgCu2+/L; or 100, 500, and 1000 µgCr6+/L during 16d. Tested concentrations ranged from those that caused no significant accumulation to those that induced growth reduction or even mortality (Cd, Cu). Concentration-dependent accumulation of Cd and Cr showed a linear and exponential relationship in the gill and liver, respectively, with a greater slope at longer exposure times. Differently, essential Cu showed a linear relationship in both tissues, and no slope increase was observed in the gill. The gill time-dependent accumulation pattern of Cd exhibited relatively long times to half-saturation and high-saturation values. The opposite was observed for Cu, while Cr showed an intermediate position. In the liver, relative half times were Cd>Cu>Cr. Conversely, Cu presented the highest saturation concentrations, Cr intermediate, and Cd the lowest. Bioconcentration of Cd was high in the gill (2000-fold) and low in the liver (50-fold). Oppositely, essential Cu was poorly retained by the gill (15-fold) and accumulated mainly in the liver (50-fold). Differently, Cr was quickly and evenly accumulated by both organs, but reaching bioconcentration levels barely above the unit. The accumulation patterns of studied metals in pejerrey corresponded more with those reported for sensitive than for tolerant fish species. The ratio of gill/liver concentration was clearly different among exposed and non-exposed fish (Cd>1; Cu<1; Cr<8), representing a potential tool to identify exposure in feral organisms.