Meeting Abstract
In amphibians, exposure to stressors early in life can have continuing negative impacts later in life. These negative consequences, including decreased body mass at time of metamorphosis as well as increased susceptibility to disease, have been demonstrated in several species of salamanders and may have broader implications for conservation. We sampled Northern stream salamander larvae, Gyrinophilus porphyriticus, from two streams that each had native fish predators in the lower reaches and none in the upper reaches. We measured baseline and stress response (to agitation) corticosterone release rates of larvae using a non-invasive water-borne hormone assay. We hypothesized that larvae from stream reaches with fish predators would have different baseline and stress response corticosterone levels than larvae from reaches without fish predators. We found that corticosterone was downregulated in larvae from reaches with fish predators. We also found that corticosterone was downregulated in the stress-induced samples from both treatments. These results indicate that the decrease in corticosterone is related to the presence of a predator but populations exposed to a predator are not chronically stressed. While mass and snout-vent length (SVL) did not vary across reaches, down regulation of corticosterone could have long term consequences on mass and SVL after metamorphosis for individuals from reaches containing predators.
