≤~95 % of energy requirement
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||P.5333 left column 3rd paragraph: "Reef-building corals are phototrophic organisms through their obligate symbiosis with dinoflagellate endosymbionts in the genus Symbiodinium, which is the most extensively studied microbial symbiont taxon of corals to date. These algal symbionts are genetically diverse, comprising nine evolutionary lineages (‘clades’) that have a most recent common ancestor c. 50 million years ago (Pochon et al. 2006), and over 100 putative species commonly referred to as ‘types’, ‘phylotypes’ (strictly subsets of taxa with close phylogenetic relationships that cluster in a monophyletic group in phylogenetic analyses—but often interchangeably used with ‘types’) or ‘subclades’ (Lajeunesse 2001, Baker 2003, Coffroth & Santos 2005, Pochon & Gates 2010). Symbiodinium species are extremely efficient utilizers of light energy (Brodersen et al. 2014), and secrete photosynthate, predominantly in the form of glucose (Burriesci et al. 2012), to the coral host tissues. In this way, Symbiodinium can meet up to ~95% of the energy requirement of the coral animal (primary sources). The symbiosis of corals with Symbiodinium also enhances calcification rates to the extent that only zooxanthellate corals are able to build the extensive calcium carbonate structures that constitute tropical coral reefs." See Iluz 2015 PMID 25467066 abstract: "The relationship between reef-building corals and light-harvesting pigments of zooxanthellae (Symbiodinium sp.) has been acknowledged for decades. The photosynthetic activity of the algal endocellular symbionts may provide up to 90% of the energy needed for the coral holobiont."