Senior Theses 2003
Diana Lea Huestis (2003). Larval life history of two-lined
salamanders (Eurycea bislineata complex) in the
EnoreeRiver basin of South Carolina with notes on factors affecting
the distribution of semi-aquatic plethodontids
Faculty advisor: Peter Meylan
Environmental factors such as habitat availability and water chemistry may limit the distributions of plethodontid salamanders. Within a species' range, abiotic factors such as temperature, humidity, and stream flow may exert selection pressures on populations and lead to the alteration of life history strategies as these populations adapt to local conditions. plethodontid salamanders were collected along with fish and aquatic insects as part of a biodiversity study on the Enoree River basin of South Carolina during the summers of 1999, 2000, and 2001. Water chemistry analyses were performed that allowed for the correlation of salamander occurrence with environmental variables to determine if water chemistry parameters affect their distributions. The presence of plethodontids was correlated with factors such as temperature and elevation rather than water chemistry, indicating that thermal regime may be more important than water quality in determining local distributions. In an effort to examine environmental effects on populations, a life history study was conducted on four populations of two-lined salamanders (Eurycea bislineata complex) to determine the length of the larval period, size at metamorphosis, and larval growth rates for each. Because two cryptic species of the complex occur in South Carolina, the species to which specimens from various study sites belonged were identified by mitochondrial DNA analysis. Sites included three montane streams and one lowland second order stream. Larvae at all three montane sites metamorphosed in late June and July of their second summer, while larvae at the lowland site metamorphosed in July and throughout August of their second summer and at a significantly larger size. These life history differences may be attributable to environmental differences between streams or to inter-specific variation.