Apicomplexa; Diversity; Genetics; Gregarines
Parasites play an important role in marine ecosystems and their diversity is generally understudied. Apicomplexans, a group of parasitic protists in the phylum Alveolata, infect a wide variety of animal hosts and are abundant in ecosystems spanning from Polar Regions to Neotropical rainforests. Previous data generated from marine sediments in Antarctica, Naples Bay, and off the coast of Oslo, exhibit high diversity and numbers of apicomplexans. Abundance and diversity of these protists are unknown for Narragansett Bay, despite the fact that they infect many commercially important species. The aim of my study was to obtain abundance data and understand genetic diversity of apicomplexans in sediment samples collected from ten locations across Narragansett Bay. This data acted as a baseline analysis for Rhode Island marine sediments and was compared to other areas of the world to determine whether apicomplexan abundance and diversity changes in response to geography. Of the species observed in sediment communities, gregarines are generally an understudied subclass. By locating conserved regions of the 18S genome, a fluorescence in situ hybridization (FISH) probe was designed to bind to complementary nucleic acid sequences. In the future, this can be used with flow cytometry to sort individual gregarines and allow single cell transcriptomic work. With marine shellfish and fisheries stimulating more than $12 million into the Rhode Island economy each year, changes in parasite virulence could disproportionately affect the state’s economy. Research to identify undescribed apicomplexans within host species from Narragansett Bay is currently ongoing and will improve our ability to model parasite dynamics among commercially relevant species.