Estimating the daily contribution of carbon from zooxanthellae to coral animal respiration1

Abstract

An equation is derived which rigorously defines the photosynthesis: respiration ratio (P:R) for any alga: invertebrate symbiotic association arid permits the computation of the fractional contribution of translocated algal carbon to the daily respiratory carbon requirement of the host animal. The equation is applied to two species of symbiotic reef corals, using O₂ flux data from 24‐h continuous measurements in situ. Given certain assumptions, the algae in the shallow‐water Hawaiian reef corals Pocillopora damicornis and Fungia scutaria can supply of the order of 63 and 69% of the daily respiratory carbon demand of their respective animal hosts.