The Effects of Hydroperiod on the Morphology of the Long-Toed Salamander Ambystoma macrodactylum

Abstract

This study was conducted to determine whether salamander larvae of Ambystoma macrodactylum growing in short hydroperiod ponds develop a cannibalistic morphology while those growing in a long hydroperiod pond develop a typical morphology. Hand and dip net capturing techniques were used to collect the larvae. They were then preserved in formalin and stored in 95% ethanol solution. Six measurements were then taken: snout-vent length, head width at gills, head width at eyes, head width at jaws, head length, and interocular width. Snout-vent-length was then scaled to the other measurements to determine differences in body shape. Using an ANOVA statistical test, these shape measurements were compared to determine if morphology of salamander larvae differ between the two sites. Results showed that there was a significant difference in morphology for all measurements except snout-vent length to interocular width. While the body morphologies from the two sites were different, the morphology from the short hydroperiod pond was not cannibalistic. Possible explanations for this include genetics, density, and diet.