As the number of species facing extinction in the wild continues to increase, the role of captive breeding programs in preserving biotic diversity will become more important. Decisions regarding management of captive populations can have large impacts on their genetic diversity and may ultimately affect the survival of threatened species. The influence of captive breeding strategies on the viability of individuals and populations will be assessed in two related experiments. First, small populations of the mosquitofish (Gambusia affinis) will be managed using one of four strategies that have been suggested for the management of captive populations. This experiment will determine how these strategies affect the reproduction, growth, development and survival of individuals in captivity. Second, individuals from these populations will be used to found populations in large microcosms, designed to simulate small ponds. This experiment will determine if the way a captive population is managed will affect its ability to establish successful wild populations. The influence of captive breeding strategies on the number of individuals that need to be released to establish successful wild populations will also be examined. This research will help improve management of captive breeding populations, while also helping to ensure the success of reintroduction programs.
