CHEMICAL ACTIVATION OF FEEDING IN THE CARIBBEAN REEF-BUILDING CORALMONTASTREA CAVERNOSA

Abstract

1. Nineteen amino acids, pipecolic acid, glutathione, glucose, fructose, and sucrose were surveyed as potential chemical activators of feeding in the massive Caribbean reef-building coral Montastrea cavernosa.2. Glutamic acid, proline, pipecolic acid, arginine, and aspartic acid active feeding in this species. Its polyps fully ingest pieces of filter paper impregnated with these compounds.3. Glutamic acid, proline, pipecolic acid, and aspartic acid produce full envelopment in 30 seconds or less. Arginine, however, requires one minute or more before eliciting closure.4. Sensitivity is greater at the mouth for proline, aspartic acid, and arginine, but greater on the tentacles for glutamic acid.5. Montastrea cavernosa responds to compounds of several chemical structural groups and therefore possibly has different chemoreceptors sensitive to each of these groups.6. Since a variety of crustacean zooplankton have been shown to contain comparable concentrations of some of these activators, the release of such compounds following puncture of zooplankton by coral nematocysts may elicit the observed capture and ingestion behavior in Montastrea cavernosa.