Salmon’s Secret Superfood discovered through ecosystem science
In the Eel River, the symbiotic triad of the green macroalga Cladophora, its Epithemia epiphytes, and the diazoplasts within Epithemia are embedded in a complex food web with thousands of other algal and bacterial species. Despite high species richness of photoautotrophs and N-fixing bacteria at the base of this food web, much of the N and C fixation is mediated by the three-member Cladophora-Epithemia-diazoplast symbiosis. The Mark’s lab recently published a paper in PNAS that shares exciting new discoveries in aquatic microbiology
“Here, we document the tractability of Epithemia spp. as an ecological model system for studies of how elemental fluxes scale through levels of biological and ecological organization in nature.”
Their results and those of others suggest that endosymbioses may help drive biogeochemical cycles and support productive food webs in many N-limited aquatic ecosystems. Deeper understanding of how Epithemia functions in nature should guide further discovery of its role in food webs and the conditions and selective pressures that influenced the evolution of its diazoplast from endosymbiont to proto-organelle.
