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TABLE 5-2 Concentration of Pesticides in 23 Lake Apopka Alligator Eggs Contaminant Mean, ppm Range, ppm trans- Nonachlor 0. 15 0.01-0.68 Dielilrin 0. 11 0.02-1.0 Oxvchlordane 0.03 NDa-0.21 cis-Chlordane 0.06 ND-0.25 trans-Chlordane 0.006 ND-0.05 Toxaphene 2.4 0.05-13 p,p'-DDE 3.5 0.89-29 o,p'-DDE 0.007 ND-0.06 p,p'-DDT 0.02 ND-1.3 p,p'-DDD 0.37 ND-1.8 a ND, not detectable. SOURCE: Heinz et al. 1991. Reprinted with kind permission from Environmental Monitoring and Assessment: copyright 1991, Kluwer Academic Publishers, Dordrecht, The Netherlands.

and hatchling alligators from Lake Apopka have elevated lipid ( 1.6-8.5 ppm) and hepatic (0.013-0.17 ppm) concentrations of p.p'-DDE. Those concentrations were significantly higher in hatchlings with developmental abnormalities. Specific reproductive anomalies found in the alligators of Lake Apopka are discussed below.

Alligators hatched from eggs collected from Lake Apopka have exhibited abnormal gonadal morphology. Male juvenile alligators had poorly organized testes with unique, aberrant structures within the seminiferous tubules (Guillette et al. 1994). Some of the germ cells had clear mitotic figures. suggesting that premature spermatogenesis had begun. No mitotic or meiotic activity was seen in the testes obtained from males of the less contaminated reference lake, Lake Woodruff. Female alligators examined at 6 mo had prominent polyovular follicles, and many of the oocytes were multinucleated (Guillette et al. 1994). A normal ovarian follicle contains a single oocyte with a single nucleus. Polyovular follicles contain more than one oocyte, and in the case of the neonatal and juvenile alligators, as many as six discrete oocytes were counted in a follicle. All females hatched from the Lake Apopka eggs exhibited this condition; none of the reference females did (Guillette et al. 1994). Follow-up studies of juvenile alligators from Lake Apopka and the reference lake indicate that some oocytes are multinucleated in females from the control group, but polyovular follicles were not seen in any of the control females (Pickford 1995).

The abnormal morphologies of the ovarian follicles and oocytes in female alligators from Lake Apopka are similar to those observed in mice treated withcontinue