Number of eukaryotic species in ocean

Range ~200,000 species
Organism Biosphere
Reference Andersen KH et al., Characteristic Sizes of Life in the Oceans, from Bacteria to Whales. Ann Rev Mar Sci. 2016 8: 217-41. doi: 10.1146/annurev-marine-122414-034144. p.219 top paragraphPubMed ID26163011
Primary Source May RM, Godfrey J. 1994. Biological diversity: differences between land and sea. Proc. R. Soc. B 343: 105–11 DOI: 10.1098/rstb.1994.0014 link
Comments P.218 bottom paragraph: "[Investigators] categorize pelagic life in the ocean based on size in seven general realms: molecular life (viruses), osmo-heterotrophic bacteria, unicellular phototrophs, unicellular mixotrophs and heterotrophs, planktonic multicellular heterotrophs with ontogenetic growth (e.g., copepods), visually foraging poikilotherms (mainly teleosts, cephalopods, and cartilaginous fish), and homeotherms (cetaceans, but not seals, penguins, or other animals that do not live their entire lives in the pelagic). This categorization of life is a deliberately crude representation of the roughly 200,000 eukaryotic species and the unknown number of archaea and bacteria in the ocean (primary source), as it is explicitly designed to facilitate an understanding based on size. [They] describe the life forms in each realm according to their body size and determine characteristic sizes where there is a transition from one realm to another (see Table 1). In this manner, [they] emphasize body size as a fundamental driver of macroecological patterns in the oceans."
Entered by Uri M
ID 112669