Confirmation of Bouamia spp. in Bivalves in the Indian River Lagoon Using Fluorescent in situ Hybridization

Various bivalve species were sampled at three sites in the Indian River Lagoon in Fort Pierce, Florida to determine whether the change in the seasonal prevalence of Bonamia spp. in the Indian River Lagoon as determined by PCR could be confirmed histologically using standard hematoxylin and eosin (H&E) staining and fluorescent in situ hybridization (FISH). Parasite location was noted in tissue samples and determinations were made as to whether the infection was external (gills, mantle) or internal (connective tissue). Bonamia spp. was found to be more prevalent in the fall at all three study sites. Fluorescent in situ hybridization confirmed the majority ofPCR-positive samples. A large
percentage of Bonamia spp. infections at North Causeway Park and Wabasso Causeway Bridge were external infections. In addition, a large percentage of Bonamia spp. infections at Wildcat Cove and Wabasso Causeway Bridge were in the gills and mantle. This indicates that most of the bivalves sampled are filtering the parasite from their surrounding environment but are not being negatively affected and those that are infected are not heavily infected. Bonamia spp. has not been reported to negatively impact bivalve populations in Florida, however the impacts of this parasite on various oyster and mussel species in Florida has not been thoroughly examined. This project may determine what steps need to be taken to prevent the losses in oyster and associated bivalve populations in the Indian River Lagoon.