healthy corals 15 - 35: bleached corals ≤100 %
||Houlbrèque F, Ferrier-Pagès C. Heterotrophy in tropical scleractinian corals. Biol Rev Camb Philos Soc. 2009 Feb84(1):1-17. doi: 10.1111/j.1469-185X.2008.00058.x abstract and p.7 left column bottom paragraphPubMed ID19046402
||Porter, J. W. (1976). Autotrophy, heterotrophy and resource partitioning in Caribbean reef-building corals. The American Naturalist 110(975), 731–742 Stable URL: link AND Sorokin, Y. I. (1993). Coral Reef Ecology. Ecological Studies. pp. 465. Springer-Verlag. Berlin AND Grottoli, A., Rodrigues, L. & Palardy, J. (2006). Heterotrophic plasticity and resilience in bleached corals. Nature 440, 1186–1189 DOI: 10.1038/nature04565 PubMed ID16641995
||Abstract: "The dual character of corals, that they are both auto- and heterotrophs, was recognized early in the twentieth Century. It is generally accepted that the symbiotic association between corals and their endosymbiotic algae (called zooxanthellae) is fundamental to the development of coral reefs in oligotrophic tropical oceans because zooxanthellae transfer the major part of their photosynthates to the coral host (autotrophic nutrition). However, numerous studies have confirmed that many species of corals are also active heterotrophs, ingesting organisms ranging from bacteria to mesozooplankton. Heterotrophy accounts for between 0 and 66% of the fixed carbon incorporated into coral skeletons and can meet from 15 to 35% of daily metabolic requirements in healthy corals and up to 100% in bleached corals." P.7 left column bottom paragraph: "Different estimations concerning heterotrophic carbon supply vary from a non-significant contribution (Johannes et al., 1970, Edmunds & Davies, 1986), through meeting 15-35% of daily metabolic demand (DME) in healthy corals (primary sources) to up to 100% in bleached corals (primary source Grottoli et al., 2006)."