Intraspecific variation in life history traits among two forms of ambystoma barbouri larvae


Variation in available resources (e.g.. environment or food) can influence life history variation. Populations of the streamside salamander (Ambystoma barbouri) breed in both streams and ponds and larvae exhibit diverse life history patterns related to the environment within which they develop. Previous experiments demonstrated that environmental factors are largely responsible for differences in larval period. mass and size at metamorphosis between the two forms of A. barbouri; however. it is unclear which environmental factors influence the variation. Under controlled laboratory conditions. we tested if hydrological differences between lotic and lentic habitats contribute to life history divergence in A. barbouri. We reared laboratory born larvae from stream- and pond-collected eggs in laboratory environments with hydrological patterns similar to their natal environments. Ambystoma barbouri stream larvae metamorphosed faster and were smaller in mass and size compared to pond larvae. Although we did not test whether genetic or environmental factors influence larval life history traits. our data provide support that hydrological variation alone may contribute to the life history variation in the two forms of larval A. barbouri.

Publication Title

American Midland Naturalist