How Long Do Trade-Offs of Predator-Induced Phenotypic Plasticity Incurred as Larvae Impact Adults?
Many organisms have the ability to alter their morphology, behavior or life history in response to environmental cues. For example, many tadpoles can alter their morphology to better escape from predators. It is unclear, however, whether morphological changes made by tadpoles in response to predators in their aquatic environment have negative consequences for later life stages when tadpoles become frogs or toads. To examine these potential consequences, we conducted an experiment where we 1) raised tadpoles of the southern toad in artificial ponds that had no predators, caged predatory dragonfly larvae, or caged predatory fish and 2) assessed morphological differences among these individuals during their larval and terrestrial juvenile stages. We assessed the performance of juveniles by raising them in penned enclosures and measured growth, survival and hopping ability. Larval toads reared with fish had shorter tails than those reared without predators. Toad metamorphs reared without predators were longer and had lower survival than those reared with dragonflies. After being added to the enclosures, there were no significant differences in number of toads, size, leg length, or hopping ability between toads reared in the three treatments. These data suggest that the consequences of larvae changing their morphology to escape predation disappear shortly after metamorphosis. These data need to be interpreted with caution because of the high mortality in the enclosures, which may have prevented the detection of differences due to small sample sizes.
P140 • Marvin E. Brown1, David R. Cann1, Jessica L. Deer2, Eran S. Kilpatrick3
Preliminary Results From a Herpetofauna Survey at Santee National Wildlife Refuge
The Santee National Wildlife Refuge (Santee NWR) is a 6070 hectare tract located in western Clarendon County, South Carolina adjacent to Lake Marion. The property is situated in the Atlantic Coastal Plain physiographic province and contains a diversity of terrestrial and wetland habitats. Santee NWR is divided into four management units: Bluff, Cuddo, Dingle Pond, and Pine Island. Multiple active and passive sampling devices were used from March 2013 - August 2013 to sample herpetofauna at nine intensive survey sites within the refuge. A total of 804 individual captures, representing 58 species, was documented for 44 survey days. Eighteen of these species were new records for Santee NWR. The majority of captures (80%) were recorded from the Bluff and Cuddo Units. The difference in capture rate across the refuge units was influenced by the large number of eastern narrow-mouthed toad (Gastrophryne carolinensis) captures in the Bluff Unit and variation in sample effort. A 170 hectare Carolina bay (Dingle Pond) and temporary isolated wetlands on the Cuddo and Pine Island units serve as important breeding habitats for Ambystoma opacum (marbled salamander), Ambystoma mabeei (Mabee’s salamander), and Ambystoma talpoideum (mole salamander). Small isolated wetlands that provide breeding habitats for these salamanders have conservation value as they are not protected as jurisdictional wetlands. Based on current species distribution maps for South Carolina, an additional 25 species could occur on the property. Surveys in year 2014 will continue in addition to an assessment of multiple habitat variables at each established sample site.
1 University of South Carolina Columbia, Dept of Biological Sciences; 2 University of South Carolina Aiken, Dept of Biology and Geology; 3 University of South Carolina Salkehatchie, Division of Mathematics and Science
P141 • Austin H. Patton1, Kristin A. Bakkegard2
Using Morphometrics to Distinguish Between Two Slimy Salamander Species in Central Alabama (Plethodon glutinosus , Plethodon mississippi)
The Plethodon glutinosus species complex is comprised of at least 13 species. When the group was first split by Highton, species ranges were approximated over large areas. Sampling did not fully account for Alabama’s physiographic regions which often influences the distribution of the state’s herpetofauna. The ranges of Plethodon glutinosus and P. mississippimeet in north central Alabama, where four of the state’s physiographic regions also converge. Complicating matters is the cryptic morphology of these two species. We used geometric and linear morphometric methodologies and multivariate statistics to determine whether we could distinguish between each species and thus refine the range of P. glutinosus and P. mississippi by classifying specimens from north central Alabama to their correct species. We found no difference in head shape between the two, but did find that P. glutinosus was significantly larger than P. mississippi in body size. This was unexpected, as geometric morphometric methods have been shown to be sensitive to subtle shape differences. It is possible that the ranges of these two species do not overlap or there is some other factor limiting interspecific competition that explains why no differences in head shape were found. Additionally, logistic regression was unable to satisfactorily classify unknown salamanders from contact zone counties. We recommend genetic studies be conducted to refine the ranges of these two species and to identify broad scale patterns of gene flow. Sampling should focus on the boundaries of Alabama’s physiographic regions and across Alabama’s major rivers.
1 Dept. of Biology, Warren Wilson College, Asheville, NC; 2 Dept. of Biological and Environmental Sciences, Samford University, Birmingham, AL
P142 • Kristen Gillespy1, Brielle Bowerman1, John D. Wilson2, Michael Dorcas1
