Meeting Abstract

P2-18  Sunday, Jan. 5  Characterizing the Digestive Microbiome of Antarctic Sea Stars CLINE, NW*; BROTHERS, CJ; MORROW, CD; CURTIS, MD; ANDERSON, SM; AMSLER, CD; SHILLING, AJ; MCCLINTOCK, JB; Walla Walla University; Walla Walla University; University of Alabama at Birmingham; University of Alabama at Birmingham; Walla Walla University; University of Alabama at Birmingham; University of South Florida; University of Alabama at Birmingham noah.cline@wallawalla.edu

Sea stars (Phylum Echinodermata; Class Asteroidea) are some of the most abundant macroinvertebrates in shallow waters surrounding Antarctica and are well-adapted to a benthic environment with limited food availability. Antarctic sea stars display opportunistic feeding behaviors including scavenging, necrophagy, and detrital feeding. However, the types of micro-organisms associated with the digestive organs of Antarctic sea stars and the importance of these microbes is not well understood. Four species of sea stars (Diplasterias sp., Lysasterias sp., Ondontaster meridionalis, and Ondontaster validus), sediment, and seawater samples (n=6, respectively) were collected from the Western Antarctic Peninsula. Digestive organs (stomachs and pyloric caeca) were dissected from the sea stars and the metacommunity 16S rRNA genes (V4 region) were sequenced using the Illumina MiSeq^TM platform. The microbial community structure of the samples was determined using bioinformatics tools. Microbial diversity of the digestive organs was lower than that of the surrounding environment (seawater and sediment), with the lowest diversity observed in the digestive organs of Diplasterias sp. The microbial community composition also varied depending on the type of sample. The changes in microbial diversity and community composition between the environment and four sea star species suggest the feeding strategies and physiological requirements of each species may play a selective role in determining the digestive microbiome of Antarctic sea stars.