The brown tube sponge Agelas tubulata (cf A. conifera) is an abundant and long-lived sponge on Caribbean reefs. Recently, a disease-like syndrome known as Agelas Wasting Syndrome (AWS) was described from A. tubulata in the Florida Keys, where prevalence of the syndrome increased from 7 to 35% of the sponge population between 2010 and 2015. In this study, we characterized the microbial symbiont community of A. tubulata for the first time from individuals collected within the same monitoring plots where AWS was described. We also sampled tissue from A. tubulata exhibiting symptoms of AWS to determine the effect of disease on the diversity and structure of microbial symbiont communities.