The rate of mucus production by corals and its assimilation by the coral reef copepod Acartia negligens1

Ahstmct The secretion of mucus by eight species of scleractinian corals was measured in situ at the Red Sea reef in Eilat, Israel. Selected coral heads were covered with plastic bags and the total organic matter collected after 24 h was determined. The rate of mucus production by massive forms was significantly greater than that by hemispherical or branched species, supporting the suggestion that the massive spccics use n~u us secretion as a mechanism to prcvcnt burial in heavy sedimentation arcas on this reef. Overall mucus production results in about 51 mg of particulate organic production nP day-‘. Laboratory feeding experiments and assimilation mcasuremcnts with Aca~tiu negligens feeding on radioactive mucus indicate that the zooplanktcrs can assimilate up to 50% of the organic matter of the mucus. Calorific determinations show this material to contain 5.2 2 0.13 cal mg-l ash-free dry weight.