Meeting Abstract
Investigating closely related, sympatric, animals with different natural diets will further our understanding of how changes in diet affect an animal’s intestinal microbial community and gut function. We examined four closely-related prickleback fishes that naturally vary in diet: Xiphister mucosus (herbivore), X. atropurpureus (omnivore), Phytichthys chirus (omnivore), and Anoplarchus purpurescens (carnivore). We are comparing enteric microbial diversity amongst wild-caught individuals of the four species, and among the wild-caught individuals and those fed different diets in the laboratory within a species. Food and feces collected throughout the feeding experiment are being used to calculate organic matter digestibility, and we are using gas chromatography to measure the concentrations of short chain fatty acids (SCFA), which are the products of microbial fermentation, in the fishes’ distal intestines. We expect some core taxa to not change in abundance in the face of dietary changes, whereas others will show dietary-related changes in abundance. As none of these fish species are known to rely on hindgut fermentation, we don’t expect SCFA concentrations to vary widely among the species or feeding treatments. We have found clear dietary effects on the microbiome. Carnivores have higher Bacteroidetes:Firmucutes ratios compared to omnivores and herbivores. Analysis of digestibility and the abundance of the various microbial taxa are underway. Our results will contribute to the larger goal of understanding how intestinal microbiomes respond to dietary shifts in animals with different natural diets, but with phylogenetic control of the studied organisms.
