WELTER, S. M.*; KOLLIKER, M.; BRODIE III, E. D.; Coastal Carolina Univ.; Indiana Univ.; Indiana Univ.: The effect of heterogeneity of the developmental environment on phenotypic plasticity of pigmentation in larval two-lined salamanders (Eurycea bislineata)

Variation in developmental environment may differentially affect trait expression. Homogeneous developmental environments typically favor fixed phenotypes, whereas heterogeneous environments can favor plastic phenotypes. We examined the effects of homogeneous and both spatially and temporally varying developmental environments on a reversible pigmentation trait believed to function in predator avoidance in larval salamanders, Eurycea bislineata. This study was designed to determine: 1) whether developmental environment influences mean trait expression and lability of traits, 2) to what extent pigment expression in larval E. bislineata is potentially genetically determined, and 3) whether there are interactions between the developmental environment and among-family genetic variation. Predictably, dorsal melanization was greater in larvae reared in a homogeneous black environment than in larvae reared in a homogeneous white background environment or either heterogeneous environments. Unexpectedly, however, heterogeneous rearing environments did not favor more flexible pigment expression than homogeneous environments. Larvae reared in one of the homogeneous environments expressed the greatest percentage of dorsal melanin mobility in response to black and white backgrounds. The flexibility of pigmentation in larval E. bislineata may therefore be limited by the developmental environment.