Masters Thesis

Use of DNA sequencing to identify the origin of Northwestern and Southwestern pond turtles in captive breeding programs

Captive breeding is a critical management strategy in the recovery and preservation of certain threatened and endangered species. Programs that implement captive breeding must maintain a balance between preserving the genetic purity and genetic diversity of a population in order to build a viable group of individuals for future reintroduction. This may be difficult due to a limited number of extant wild individuals for establishment of founder populations, leading to an increased risk of inbreeding or outbreeding depression in subsequent generations. In this study, I worked in collaboration with 24 zoos, museums, and aquariums through the Western Pond Turtle Species Survival Plan Sustainability Project to aid in conservation of two threatened and endangered freshwater turtle species through captive breeding. As individuals of the two different species can appear morphologically identical, I used DNA sequencing to identify wild-bred Northwestern (Actinemys marmorata) and Southwestern Pond Turtles (Actinemys pallida) to build captive brood stock of both species. Relatively few studies have assessed conservation efforts in consideration of two genetically distinct species within the genus Actinemys as the majority of research on this clade was done before the discovery of a second species. Here, I analyzed the nicotinamide adenine dehydrogenase subunit four (ND4) mitochondrial gene to identify species and geographic origin for 133 captive pond turtles including 71 members of A. marmorata and 62 A. pallida individuals. Results of this study were used to inform captive breeding program collaborators so that husbandry is managed in consideration of species, geographic origin, and the subsequent risks of outbreeding and inbreeding depression.