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

BELDOMENICO, P.M.; REY, F.; PRADO, W.S.; QUERCHI, Y.; VILLARREAL, J.C.; MUÑOZ-DE-TORO, M.; LUQUE, E.H.

ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY

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 1C) and humidity (490%). They were treated with vehicle, 17 b-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 ¼ 0.0005). These pesticides also caused a reduction in hatchling fractional weight (p ¼ 0.0497). These effects might have a significant impact on caiman population dynamics.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 1C) and humidity (490%). They were treated with vehicle, 17 b-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 ¼ 0.0005). These pesticides also caused a reduction in hatchling fractional weight (p ¼ 0.0497). These effects might have a significant impact on caiman population dynamics.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 1C) and humidity (490%). They were treated with vehicle, 17 b-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 ¼ 0.0005). These pesticides also caused a reduction in hatchling fractional weight (p ¼ 0.0497). These effects might have a significant impact on caiman population dynamics.1C) and humidity (490%). They were treated with vehicle, 17 b-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 ¼ 0.0005). These pesticides also caused a reduction in hatchling fractional weight (p ¼ 0.0497). These effects might have a significant impact on caiman population dynamics.p ¼ 0.0005). These pesticides also caused a reduction in hatchling fractional weight (p ¼ 0.0497). These effects might have a significant impact on caiman population dynamics.p ¼ 0.0497). These effects might have a significant impact on caiman population dynamics.