Necropsy Findings in American Alligator Late-Stage Embryos and Hatchlings From Northcentral Florida Lakes Contaminated With Organochlorine Pesticides

Abstract

ABSTRACT:Increased American alligator (Alligator mississippiensis) embryo and neonatal mortality has been reported from several northcentral Florida lakes contaminated with old-use organochlorine pesticides (OCPs). However, a clear relationship among these contaminants and egg viability has not been established, suggesting the involvement of additional factors in these mortalities. Thus, the main objective of this study was to determine the ultimate cause of mortality of American alligator late-stage embryos and hatchlings through the conduction of detailed pathological examinations, and to evaluate better the role of OCPs in these mortalities. Between 2000 and 2001, 236 dead alligators were necropsied at or near hatching (after ,65 days of artificial incubation and up to 1 mo of age posthatch). Dead animals were collected from 18 clutches ranging in viability from 0% to 95%. Total OCP concentrations in yolk ranged from ,100 to 52,000 mg/kg, wet weight. The most common gross findings were generalized edema (34%) and organ hyperemia (29%), followed by severe emaciation (14%) and gross deformities (3%). Histopathologic examination revealed lesions in 35% of the animals, with over half of the cases being pneumonia, pulmonary edema, and atelectasis. Within and across clutches, dead embryos and hatchlings compared with their live cohorts were significantly smaller and lighter. Although alterations in growth and development were not related to yolk OCPs, there was an increase in prevalence of histologic lesions in clutches with high OCPs. Overall, these results indicate that general growth retardation and respiratory abnormalities were a major contributing factor in observed mortalities and that contaminants may increase the susceptibility of animals to developing certain pathologic conditions.

Teratological Effects of Dimethoate on 12th Day Desi Chick Embryo (Gallus gallus domesticus)

“…Chlorpyrifos, cypermethrin, spinosad, malathion and endosulfan also have similar effects on different organs during embryonic development (Mobarak and Al-Asmari, 2011;Uggini et al, 2010;Anwar, 2003;Pourmirza, 2000). Furthermore, Sepulveda et al (2006) and Singh et al (2007) described malformations in different body structures in alligator and rat embryos when exposed to citrinin, endosulfan and organochlorine insecticides.…”

A third case of amelia in Morelet’s crocodile from the Yucatan Peninsula

“…Furthermore, higher rates of thyroid dysfunction, hatching success, egg shell thinning, and gross birth deformities in numerous wildlife populations across the world have been related to habitat contamination (Hamlin & Guillette 2010). In crocodilians, several birth defects related to endocrine system disruption have been observed in a wild population of A. mississippiensis inhabiting a contaminated lake (Guillette & Milnes 2001, Sepúlveda et al 2006. However, no direct relationships between the high level of contaminants and deformities have been proved.…”

Organochlorine compound residues in the eggs of broad-snouted caimans (Caiman latirostris) and correlation with measures of reproductive performance

“…Clutch size and hatching success are measures of reproductive performance in oviparous species. Field and laboratory studies suggested that parental exposure to OCCs may contribute to low clutch viability (de Solla et al, 2008;Lundholm, 1997;Rauschenberger et al, 2004Rauschenberger et al, , 2007Sepúlveda et al, 2006). In this background, we conducted a study to estimate the OCC residues present in the eggs of C. latirostris from northeastern Argentina and to determine the relationship between OCC concentrations and measures of reproductive performance.…”