ECOLOGY OF THE BEARDED FIREWORM, HERMODICE CARUNCULATA (AMPHINOMIDAE: ANNELIDA)
Loading...
Date
2020-07-31
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
My dissertation research is a multidisciplinary approach to characterize the ecology of the bearded fireworm, Hermodice carunculata (Phylum Annelida: Family Amphinomidae). This species is often considered a nuisance as it is a mobile corallivore, consumer of corals, and possesses bristles that cause a burning sensation in humans lasting several hours. As the bearded fireworm is found throughout the Atlantic Ocean’s basins, , it has a wide range of environmental tolerances. My dissertation sought to understand this species’ morphological (Chapter 2) and physiological (Chapter 3) responses to chronic (>18 hours) low dissolved oxygen (DO), or hypoxic, conditions. After 7 days of chronic hypoxia, Chapter 2 shows the branchial filament number (similar to the gills of fish) was higher in the lowest DO condition compared with the normal condition. We also saw an increase in metabolic rates after chronic hypoxic exposure in Chapter 3. Then in Chapter 4, we investigated differential gene expression analyses of fireworms exposed to chronic and intermittent hypoxia resulted in up-regulation of tissue differentiation, blood-vessel formation, and blood pigment oxygen binding efficiency. Those exposed to intermittent (6 hours) hypoxia had higher regulation of epithelial cell differentiation and oxidative stress response. The bearded fireworm is also considered a nuisance due to its vectoring capabilities of marine microbial diseases, especially coral diseases. In Chapter 5, we investigated the interaction between the microbial communities (or microbiomes) of different portions of the bearded fireworm, substrate, healthy, and bleached coral colonies (Montastrea cavernosa). We used the Bayesian statistical software SourceTracker to predict the bacterial sources and sinks for bacteria of interest. The bleached M. cavernosa served as a major source for the bacterial communities associated with whole worm samples, but not for those associated with the digestive tract. Understanding how these fireworms respond to hypoxia, negatively impact coral communities, and how their bacterial communities are related to those corals leads to an improved understanding of marine bacterial community dynamics which may inform bleaching-mitigation efforts.
Description
Keywords
Annelida, Hypoxia, Metabolism, Branchia, Coral Disease, Microbiomes