Meeting Abstract

P1.173  Saturday, Jan. 4 15:30  Population Genomics of a Trophically Polymorphic Cuatro Ciéngeas Cichlid, Hericthys minckleyi BELL, K.L.*; NICE, C.C.; HULSEY, C.D.; Texas State University; Texas State University; University of Tennessee kbell@txstate.edu

Resource polymorphism in vertebrates has the potential to be a diversifying force leading to population divergence and speciation. In several diverse taxa, discrete intraspecific morphs show differential resource use and varying degrees of reproductive isolation. Alternatively, resource polymorphism may phenotypically characterize hybridizing lineages that are in the process of collapsing into one species. We used high through-put sequencing to investigate the evolutionary factors involved in the maintenance of alternate morphotypes in a highly variable species of cichlid. Hericthys minckleyi is a species of cichlid endemic to a small valley, Cuatro Ciénegas, in the center of Mexico’s Chihuahuan desert. Pharyngeal tooth size divides H. minckleyi into two discrete phenotypes, with associated feeding differences. We found evidence of genetic differentiation between allopatric populations of H. minckleyi in the Cuatro Ciénegas valley. We also detected genetic differentiation between the sympatric alternate morphotypes. Our results found little evidence of nuclear introgression between H. cyanoguttatus, a closely related species, and H. minckleyi and thus did not find support for the hypothesis that alternate morphotypes may represent collapsing hybridizing lineages. Further work is required to delineate the complex evolutionary relationships and the factors involved in the maintenance of alternate morphotypes in this system.