Meeting Abstract

P2.96B  Monday, Jan. 5  Genetic diversity and feeding preferences in the North Atlantic marine isopod, Idotea balthica BELL, T.M.*; WARES, J.P.; University of Georgia; University of Georgia tmbell@uga.edu

Organisms experience abiotic and biotic factors that vary in time and space as well as in presence and intensity, even over short distances. Spatio-temporal environmental heterogeneity that occurs throughout a species range can result in different selective pressures between populations, whereby alleles favored in one region of a species range may be disadvantageous in other regions. Thus, variation in natural selection can lead to local adaptation and maintenance of genetic and phenotypic diversity within a species. The marine herbivorous isopod species, Idotea balthica, is distributed throughout the North Atlantic and exhibits deep population genetic divergence among populations along the northeastern coast of North America at the mitochondrial cytochrome oxidase 1 (mtcoI) gene and in AFLP markers. The diversity of intertidal marine macroalgae changes quite dramatically along this coastline in a pattern that is similar to the population genetic patterning found in I. balthica. Feeding preference and food choice assays were conducted with I. balthica using eight different algal species in order to determine if genetically distinct lineages have specialized on the macroalgal species available to the local populations. Individuals were taken from natural populations and the stomach content was analyzed using universal algal molecular markers in order to determine the accuracy of laboratory feeding assays and the algal species diversity consumed by populations.