Population biology
Scanning electron microscope images of Emiliania huxleyi coccospheres, some multi-layered.
E. huxleyi:
- frequently dominates coccolithophore assemblages
- is the most abundant single coccolithophore species
- is the dominant bloom-forming species (Westbroek et al. 1993)
Why is E. huxleyi so abundant?
Possibly E. huxleyi has evolved unique features which enables it to out-compete other species in a wide range of environments.
Intriguingly, the species shows enormous variation in the ratio of coccolith calcite to cellular biomass as a result of the:
- open structure of its coccoliths, which allows great variation in the mass of individual coccoliths
- very variable number of coccoliths borne by individual cells
While most coccolithophore species consistently produce a single layer of coccoliths, E. huxleyi frequently over-produces coccoliths. This results in the formation of multi-layered coccospheres and/or the release of numerous coccoliths into the water column.
Possibly this ability to calcify to varying degrees has given E. huxleyi a unique adaptive advantage.