Persistent organic contaminants and steroid hormones levels in Morelet's crocodiles from the Southern Gulf of Mexico.
Arch Environ Contam Toxicol
; 62(3): 445-54, 2012 Apr.
Article
em En
| MEDLINE
| ID: mdl-22002785
Effects of endocrine disruptors on reproductive variables of top predators, such as alligators and crocodiles, have long been cited. Due to their long life span, these predators provide us with historic contaminant annals. In this study we tried to test whether lifestyle (free-ranging vs. farm animals) and reproductive age of Morelet's crocodiles in Campeche, Mexico, affect the bioaccumulation of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). Subsequently, we tested to see whether their concentration was related to steroid hormones (testosterone and estradiol-17ß) levels once normal cyclic hormone variation and reproductive age had been taken into account. From the group of contaminants considered (analyzed as families), only frequency of hexachlorocyclohexanes (∑HCH) and ∑PCB permitted analyses. Whereas there was a greater concentration of ∑HCH bioaccumulated by free-ranging crocodiles, ∑PCB was found in equal quantities in free-ranging and farm animals. No difference was observed in relation to reproductive age for any of the contaminants. However, ∑PCB concentrations were related to testosterone levels among female crocodiles. This androgenic effect of ∑PCB has not been reported previously. Because testosterone promotes aggressive behavior in vertebrates, excessive aggression during the estrous season, or when female crocodiles should be caring for their young, could result in reproductive failure in Morelet's crocodiles and potential long-term decline of the population.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Hormônios Esteroides Gonadais
/
Poluentes Químicos da Água
/
Jacarés e Crocodilos
Limite:
Animals
País/Região como assunto:
Mexico
Idioma:
En
Revista:
Arch Environ Contam Toxicol
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
México
País de publicação:
Estados Unidos