The ecology and evolution of organisms can often be explained by specific mechanisms involving molecules, genes, and cellular characteristics. Being lungless, salamanders require moist skin to breathe. By maintaining moist skin, salamanders lose water to their environment, and consequently, the amount of time they can forage is determined by the rate at which salamanders lose water to their environment. Salamanders with high skin resistances (and thus lower water loss rates) can be active for longer periods, potentially increasing their fitness. In lungless salamanders, adults have a distinct advantage over juveniles due to their higher skin resistance to water loss. However, the mechanism by which adult salamanders have higher skin resistances than juveniles remains an unanswered question. Here, we use a variety of histological and lipid assays to determine differences between skin structure and skin secretion composition between large and small bodied salamanders. Skin secretions were collected from live individuals, stained with Sudan Black B, and analyzed using ImageJ to characterize lipid content. Skin samples were also stained with hematoxyline-eosin solution to investigate skin morphology. The results indicated that lipids may play an important role in determining skin resistance of small salamanders. The histological assays indicate dramatic differences in skin morphology across body sizes, with larger salamanders having much thicker skin.Therefore, the interaction between skin morphology and physiological responses will determine how salamanders respond to their environment.
Matlack, Meghan; Rutledge, Meredith; Riddell, Eric; and Sears, Mike, "Mechanisms that Regulate Skin Resistance to Water Loss Rates in Plethodon Salamanders Across Various Body Sizes" (2015). Focus on Creative Inquiry. 129.