Effects of antibiotic administration on eastern oysters and blue mussels

Suspension-feeding bivalves are critical members of aquatic ecosystems worldwide. Experiments that artificially diminish the native microbial communities of bivalves in vivo will be increasingly necessary to evaluate the functional role of microbes within their hosts. The goal of this study was to evaluate antibiotic administration as a method for perturbing the gut microbiome of bivalves in two separate, but related experiments. In the first, a mixture of antibiotics was delivered to eastern oysters for four days. In the second, the same antibiotic mixture was administered to blue mussels for 21 days. In both experiments, animals were administered antibiotics in isolation, and stringent sterilization methods were employed, which included sterilized seawater and microalgal food.