Breeding threatened and endangered animals in captivity and their subsequent release can help supplement wild populations. Within captive breeding programs, maintaining genetic diversity is an important consideration for ensuring the survival of a species as a whole. Preserving genetic diversity increases population persistence, as it may offer a better chance for a species to adapt to a changing environment. The Copperbelly Water Snake (Nerodia erythrogaster neglecta, CWS) is listed as threatened by the U.S. Fish and Wildlife Service. In an effort to aid CWS recovery efforts, the Toledo Zoo manages a captive breeding program initially consisting of nine adult and seventeen juvenile snakes. To choose breeding pairs, the zoo required relatedness estimates for the adult snakes, and the juveniles were used to determine if these snakes exhibit multiple paternity. These analyses will help inform the breeding plan so that the population retains the maximum amount of genetic diversity. We generated genetic data for seven polymorphic microsatellite loci and determined relatedness using the program COANCESTRY. Relatedness varied from -0.915 to 0.5747 among all the analysis methods, with the average sibling relatedness value from all analysis methods being 0.139. The best breeding pairs are the ones that minimize these values, as these pairs will likely yield offspring with the most genetic diversity. Multiple paternity was evaluated by comparing the genotypes of the juveniles and their mother. There was no evidence supporting multiple paternity in this clutch; however, it cannot be ruled out in this species due to the small sample size of this captive population. Captive breeding efforts informed by genotyping breeding animals, like this one, may help species recover from their threatened status.
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