ASSIMILATION OF PHOTOSYNTHETIC PRODUCTS OF ZOOXANTHELLAE BY A REEF CORAL

Abstract

1. The hermatypic coral, Pocillopora damicornis was incubated in the laboratory and in its reef habitat with Na₂¹⁴CO₃ for 1-24 hours. Controls were incubated in darkness. ¹⁴C fixation in light exceeded that in darkness. 2. Fractionation of corals labeled on the reef for 24 hours revealed that 35-50% of the total ¹⁴C fixed appeared in the animal tissue lipid (as ¹⁴C-glycerol) and protein. From a comparison with dark controls it is concluded that photosynthetic products of zooxanthellae are translocated to host coral tissue. The skeletal organic matrix also acquires ¹⁴C. 3. Zooxanthehellae isolated from corals and incubated in a homogenate of host coral tissue selectively release glycerol and traces of other organic material including glucose, alanine, and glycolic acid confirming previous observations.