Meeting Abstract

P3.28  Saturday, Jan. 5  Not everything is bigger in Texas; developmental analysis between Texas and Arizona populations of Spea bombifrons reveals striking intestine growth differences. STORZ, Brian/L*; NITZBERG, Brian/W; MOERLAND, Timothy/S; Florida State University, Tallahassee, FL bstorz@bio.fsu.edu

Many species show phenotypic differences among populations across their distributions that can be the result of local adaptations. The Great Basin spadefoot toad Spea bombifrons is a promising model for studies of local adaptations. First, this species occupies a distribution spanning Northern Mexico to Southern Canada, and within this range, populations are exposed to a number of differences including terrestrial habitat types, seasonal temperature variation, elevation, ephemeral pond productivity and ecology, and soil types. Second, Spea bombifrons show very little dispersal during their life cycles and remain in relatively localized areas, which is due to their life history. As a first step towards studies of local adaptation in Spea bombifrons, we collected adults from the Kansan prairie grassland biota of the Great Plains and from the Chihuahuan desert scrub habitat and conducted a developmental analysis of their tadpoles reared in a common environment. We found little to no difference for the majority of measured traits, including developmental stage (at day 24/25 AZ 37.11, TX 38), head width (at day 24/25 AZ 10.09, TX 9.41), hind-limb length (at day 24/25 AZ 4.43, TX 5.22), tail length (at day 24/25 AZ 31.43, TX 31.20), and snout-to-vent length (at day 24/25 AZ 18.16, TX 18.87). Intestine length, on the other hand, was hugely different between Texas and Arizona populations, and in fact, Arizona tadpoles show twice the intestine length than those from Texas (at day 24/25 AZ 336.33, TX 161.98). Research supported by American Heart Association fellowship # 1 1306 0059.