Eurytemora affinis complex (Atlantic clade)

Copepods form the largest biomass of metazoans in the world’s oceans, and dominate zooplankton assemblages in nearshore environments. In particular, the copepod Eurytemora affinis has an enormous biomass (10^4-10^5/m3) in many coastal systems worldwide, including the Gulf of Mexico, St. Lawrence, Chesapeake Bay, Columbia River estuary, Baltic Sea, and estuaries of Europe. This copepod is a dominant grazer of algae and major food source for some of the world's most important fisheries, such as herring, anchovy, salmon, and flounder. Given the numerical dominance of E. affinis in coastal waters, with estimated census sizes in the billions, this copepod has significant impacts on coastal ecosystems.

Moreover, there has been great interest in E. affinis as a waterborne disease vector. Copepods harbor an enormous biomass in their microbiomes. Our sequencing of the E. affinis microbiome has uncovered several putatively pathogenic taxa (not present in the surrounding water), including Vibrio cholerae, Salmonella, Shigella, Campylobacter, Corynebacterium diphtheriae, Yersinia, Aeromonas hydrophila, and Acinetobacter haemolyticus.

E. affinis is an invasive species, which moves readily from coastal habitats into inland waters, such that the composition of its microbial community could have serious implications for disease transmission. E. affinis exhibits rapid physiological evolution during invasions from coastal into inland waters, as well as shifts in its microbiome during invasions. Thus, E. affinis provides a valuable model for studying evolution during biological invasions as well as the transport of pathogens by invasive hosts. Waterborne diseases are poorly understood, and E. affinis provides the opportunity to study pathways and mechanisms of waterborne disease transmission.(1)

Data were generated by the Baylor College of Medicine's i5k pilot project.