The abundant pteropod (pelagic snail), Limacina helicina antarctica, is a dominant grazer along the Western Antarctic Peninsula (WAP) and plays an important role in regional food web dynamics and biogeochemical cycling. Here, for the first time, we examined the gut microbiome and feeding ecology of L. h. antarctica in an austral summer by analyzing gut contents via high-throughput sequencing of 16S and 18S rRNA genes along the WAP.