DAMAGE AND REGENERATION - LINKS TO GROWTH IN THE REEF-BUILDING CORAL MONTASTREA-ANNULARIS

The influence of colony tissue regeneration on growth was studied in t he reef-building coral Montastrea annularis (Ellis and Solander, 1786) by buoyant weighing. Experimental corals consisted of a series of cor es, 2 cores from each of 20 colonies. One core of each pair was artifi cially damaged by removing approximately 1 cm(2) of tissue and skeleto n, the other served as a control for normal growth. Growth was measure d as calcification, i.e. mg calcium carbonate production. There was a linear relation between growth and solar radiation. Variation in growt h, calculated before the regeneration experiment, was insignificant be tween cores from the same colony but significantly different between c olonies. Growth was reduced in damaged cores when compared to controls . Calcification decreased immediately upon damage and remained reduced during the whole study (56 d). Lesions caused by physical damage did not always close completely. We propose and test a model that describe s regeneration in terms of closure of lesions. This model includes an asymptote in an exponentially decreasing function. Calcification remai ned suppressed after regeneration slowed down and lesions were still n ot completely closed, probably because of the formation of polyps and skeletal features in the new tissue. We suggest regeneration to be fue lled by polyps and tissue directly bordering the damaged area. Also, s uccessful regeneration depends on the amount of tissue bordering a les ion and not on colony size.