Meeting Abstract
Crassostrea virginica (eastern oysters) are ecologically and economically valuable organisms in coastal Louisiana. Understanding the nuanced relationships between C. virginica hosts and associated microbiota could be the key to maintaining healthy populations along a dynamic coastline. This study utilizes the natural salinity gradient along the Louisiana Gulf coast to analyze the effect of variable environmental conditions and disease on the C. virginica microbiota. Oysters were collected from two parent sites in Louisiana: Lake Calcasieu (19.4 ± 2.5ppt) and Vermillion Bay (3.9 ± 1.9ppt). Oyster stocks were spawned at the Louisiana Sea Grant Grand Isle Hatchery, and offspring were outplanted to Grand Isle (19.9 ± 4.2ppt) and LUMCON (8.0 ± 3.5ppt) for 14 months. Oyster gill tissue and pallial fluid samples were collected from both sites in July and October of 2018. Microbial DNA was extracted from gill tissue and pallial fluid samples and sequenced for 16S rRNA (V4 region) using Illumina HiSeq for 2x250bp reads. The progression of Dermo infection, caused by parasitic protozoan Perkinsus marinus, was measured and recorded for all individuals. By comparing microbiomes from gill tissue and pallial fluid and different environmental conditions, we were able to gain an initial understanding of the diversity of the C. virginica microbiota. Data suggest signature microbial communities for gill tissue and pallial fluid, as well as outplant-site specific community structure. Similar patterns are expected for seasonal differences and disease states. These fundamental differences in microbial communities could be associated with host responses to changing environmental conditions and could influence oyster fitness and overall population health.
