In ovum exposure to pesticides increases the egg weight loss and decreases hatchlings weight of Caiman latirostris (Crocodylia: Alligatoridae)

BELDOMENICO PM; REY F; PRADO WS; VILLARREAL JC; MUNOZ-DE-TORO M; LUQUE EH

ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 2007 vol. 68 p. 246 - 251

0147-6513

The increasing use of pesticides affects ecosystem health. Caiman latirostris is a South American species with ecological and physiological features that render it vulnerable to exposure to pesticides with endocrine disruptor´s action. Our main objective was to test the effect of in ovum exposure to atrazine and endosulfan on the sex ratio of caiman hatchlings; however, we are also presenting unexpected findings regarding pesticide effects on egg weight loss during incubation and hatchlings relative weight. Caiman eggs were incubated under controlled temperature (30 and 33 °C) and humidity (>90%). They were treated with vehicle, 17 â-estradiol (1.4 ppm), atrazine (0.2 ppm) and endosulfan (0.02; 2; 20 ppm). Pesticides did not cause estrogen-like effects on sex determination. Greater egg weight loss was observed in eggs treated with atrazine and higher doses of endosulfan (2 and 20 ppm) (p=0.0005). These pesticides also caused a reduction in hatchling fractional weight (p=0.0497). These effects might have a significant impact on caiman population dynamics.