Meeting Abstract
The microbiome of the sea urchin Lytechinus variegatus plays a crucial role in maintaining its digestive health and innate immunity. This sea urchin is an ecologically important herbivore associated with seagrass beds where it is seasonally exposed to temperatures near its upper thermal limit. Accordingly, it is important to evaluate whether predicted near-future seawater temperatures resulting from climate change will impact the community structure and predicted functional attributes of the microbiota associated with the tissues of L. variegatus. Sea urchins were exposed to current and near-future seawater temperature treatments (26 and 30°C; n=5 per treatment) for 90 days while being fed a diet of the seagrass Thalassia testudinum. After 90 days, sea urchins were sacrificed and samples from both temperature treatments (seawater, food, intestinal tract, coelomic fluid, digested food, and feces) were collected. The metacommunity 16S rRNA genes (V4 region) were sequenced using the Illumina MiSeq™ platform, and community composition and associated predicted functions were determined using bioinformatics tools. Though marginal shifts in microbial community structure were observed in response to elevated temperature, the PICRUSt predicted metabolic profiles revealed significant changes in key KEGG metabolic categories, including amino acid and carbohydrate metabolism and membrane transport. These results suggest that predicted near-future climate induced increases in seawater temperature may shift microbial community function and potentially impact sea urchin digestive physiology.
