Chemosymbiotic relationships

 

Previously, our investigated the symbionts of Alvinella pompejana, a polychete found at Deep Sea hydrothermal vents along the East Pacific Rise.  Currently, our lab is researching chemosymbiotic bacteria in the Lucinidae clams Ctena orbiculata, Phacoides pectinatus, and Stewartia floridana.

 

All known clams of the Lucinidae family harbor chemosymbiotic bacteria that fix carbon and supply it to their hosts in the absence of sunlight. Because lucinids are very abundant in shallow marine sediments, their effects on porewater composition, nutrient suspension, sediment biogeochemistry and vegetation productivity are considerable. However, their roles in sediment N and methane cycling are unknown, especially compared to other chemosymbiotic systems in deep-marine settings. Moreover, it is unclear how a decline in lucinid populations and/or functional diversity may impact coastal biome and ecosystem services, or even what could lead to lucinid population declines overall. This project is investigating the underexplored genetic, taxonomic, and functional diversity of lucinid chemosymbioses in shallow marine environments ranging from pristine to highly altered. This work is part of a large (3 PI) collaboration, where our lab is using a metagenomics and metatranscriptomics approach to characterize the phylogenetic and functional diversity of symbionts. This research is expected to fill gaps in our understanding of lucinid chemosymbiotic systems, including identifying novel bacteria and symbiotic pathways previously undescribed in lucinids.

 

Study Site 

 

Florida, California, the Bahamas

 

Current and Former Lab Participants

 

Jean Lim, Louie Alexander, Michelle Baldassare, Briana Knight, Erika Nachman, Erin Walker, Jill Walton, Brenton Davis, Danielle Gill

 

Presentations/Papers

 

NSF summary, 10+ presentations

 

Funding

 

NSF, DEB 1342785, Dimensions: Collaborative Research: Functional diversity of chemosymbiosis in lucinid bivalves from coastal biomes. co-PI with Annette Engel, UTK as PI and Laurie Anderson, co-PI, South Dakota School of Mines and Technology