Laramore, Susan E.

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.

Bivalves are important aquatic species that are an integral part of food web dynamics and nutrient cycling. As filter feeding organisms, bivalves impact on aquatic habitats, includes their ability clean up the surrounding water which allows under water plants to receive sunlight, increase oxygen and provide additional habitat to that provided by created oyster reefs. Oyster diseases such as Bonamiosis caused by the parasite Bonamia spp. may decimate bivalve populations, causing a potential threat to the
habitat of other aquatic organisms. The objective of this study was to identify the seasonal prevalence of Bonamia spp. in bivalve populations and correlate that to its environmental preference (i.e. salinity, temperature.). The results of this study show that Bonamia spp. is not only present in multiple sites and multiple bivalve species in the Indian River Lagoon, FL but is more prevalent in the fall compared to the other seasons as is seen with other oyster parasites, such as Perkinsus spp. This points for the need for additional studies to determine if Bonamia spp are having an impact on the bivalve populations in Florida and whether this parasites is causing an impact to the surrounding environment.

Habitat refuges are important ecological spatial components that can alter the survivability of organisms by providing relief from ecological pressure, such as predation, disease prevalence, and environmental stressors. If a habitat is considered to be a disease refuge this means that something unique occurred that reduced disease prevalence and intensity. Two different types of oyster habitats (mangroves and reefs) and micro habitats (low and high prop roots and reefs) were studied to determine whether differences in the internal environmental of oysters varied between habitats. Analysis of internal oyster surface and body temperatures along with oyster body salinity showed that differences in microhabitats affected body temperature and salinity. Oysters in both mangrove habitats exhibited lower body salinity and lower temperature than those on oyster reefs. We also analyzed disease prevalence and intensity of Perkinsas marinas among the different habitats and micro habitats by collecting oysters that were >1 year old. Results indicated variability of disease prevalence and intensity among the different habitats, with lowered disease prevalence and intensity seen on mangrove prop roots. These results indicate that mangrove prop roots may provide a habitat refuge for oysters from the parasite Perkinsas marinas.

The sea anemone Aiptasia pallida is a biological model for anthozoan research.
Like all cnidarians, A. pallida possesses nematocysts for food capture and defense.
Studies have shown that anthozoans, such as corals, can rapidly increase nematocyst
concentration when faced with competition or predation, suggesting that nematocyst
production may be an induced trait. The potential effects of two types of tissue damage,
predator induced (Lysmata wurdemanni) and artificial (forceps), on nematocyst
concentration was assessed. Nematocysts were identified by type and size to examine the
potential plasticity associated with nematocyst production. While no significant
differences were found in defensive nematocyst concentration between shrimp predation
treatments versus controls, there was a significant difference in small-sized nematocyst in
anemones damaged with forceps. The proportions of the different types of nematocysts between treatment types were also found to be different suggesting that nematocyst
production in A. pallida is a plastic trait.