Life history, ecology, and conservation genetics of the striped newt (Notophthalmus perstriatus)

The striped newt (Notophthalmus perstriatus) is a salamander endemic to south Georgia and north-central Florida. The species has declined throughout its range because of habitat destruction and modification. Before my research, little was known about striped newt life history.; To learn more about striped newt ecology in order to make management and conservation recommendations, I studied several aspects of striped newt life history. I used a multidisciplinary approach that incorporated fieldwork, a laboratory experiment, and DNA sequencing. For 2 years I monitored drift fences at a north-Florida breeding pond and in the sandhill uplands around the pond. This method was used to determine basic parameters of the species' life history. In the laboratory experiment I reared individual larvae on different food regimes to test the influence of growth rate on life-history expression. A portion of the Cytochrome b gene was sequenced to determine genetic population structure.; Field-collected data showed that striped newts have a complex life-cycle, involving terrestrial and aquatic stages. An individual may move between a breeding pond and upland retreats multiple times during its life. Larval development occurs in the pond, but once metamorphosis is complete, individuals leave the pond and may disperse in excess of 500 m from the pond. Striped newts may express one of two life-history pathways. An individual may initiate metamorphosis and disperse from the pond before it matures (metamorph), or it may remain in the pond and mature while retaining larval characteristics (paedomorph). The metamorph vs. paedomorph “decision” is not controlled by growth rate per se, but is likely influenced by a suite of genes. Based on DNA sequence data, significant population genetic structure was found among ten locations sampled throughout most of the species' range, showing that gene flow is severely restricted among populations.; It appears that striped newts form metapopulations and that long-term survival of the species depends on preserving those metapopulations that persist. Conservation efforts should focus on protecting and managing upland and aquatic habitats. A landscape approach is most effective, and prescribed fire in the landscape is essential.