INVESTIGADORES
SOMOZA Gustavo Manuel
artículos
Título:
Effects of cypermethrin chronic exposure and water temperature on survival, growth, sex differentiation, and gonadal developmental stages of Odontesthes bonariensis (Teleostei).
Autor/es:
CARRIQUIRIBORDE, PEDRO; DÍAZ, JUAN; LÓPEZ, GABRIELA C.; RONCO, ALICIA; SOMOZA, GUSTAVO M.
Revista:
CHEMOSPHERE
Editorial:
Elsevier
Referencias:
Año: 2009 vol. 76 p. 374 - 380
ISSN:
0045-6535
Resumen:
Abstract This study assessed the effects of cypermethrin and temperature on the survival, growth, sex differentiation, and gonadal development of Odontesthes bonariensis, a gonochoristic teleost with a strong thermolabile sex differentiation. Two complementary trials were conducted. In the first trial, newly born larvae were exposed during six weeks to 0 or 0.1 µg l-1 of cypermethrin at 17, 22, and 29°C. In the second trial, larvae were exposed at 22°C to 0, 0.1, or 0.125 µg l-1 of cypermethrin, and parallelly to 100 µg l-1 of the non-steroidal antiestrogen tamoxifen. Fish survival and growth were affected by cypermethrin exposure, water temperature, and the combination of both factors. The survival rate decreased at higher temperatures and cypermethrin concentrations, but the insecticide toxicity was inversely related to temperature. Growth was lower at 17°C than at 22 and 29°C, and was significantly increased by cypermethrin exposure. As already described for this species, all females or males were obtained at 17 or 29°C, respectively, and neither cypermethrin nor tamoxifen exposure was capable of changing sex ratios. Slight changes in gonadal development were induced only by temperature. Finally, results showed that the in vitro antiestrogenic effect reported for cypermethrin had no in vivo effects on the sex ratio, the gonadal development, or the gem cell production of O. bonariensis, even at concentrations that affected the growth and survival of the fish.