ZUR OKOLOGIE UND WUCHSFORM DER SAULENKORALLE DENDROGYRA CYLINDMS EHRENBERG BEOBACHTUNGEN IN DEN RIFFEN DER INSEL SAN ANDRÉS (KARIBISCHES MEER, KOLUMBIEN

Submarine observations around San Andres Island indicate that quiet backreef and leeward reef waters from 1 to 20 m deep, are the most favorable habitat for the pillar coral Dendrogyra cylindrus. It thrives even at the submarine terraces along the calm West coast of the Island, where abrasive action by coral fragments is heavy during occasional storm surges. Besides a few minor incrusting and hemispherical species, Dendrogyra seems to be the only major scleractinian to resist abrasion and break-down without permanent damage in this environment. Dendrogyra initiates colony growth with a broad incrustation followed by upgrowth of pillars. Unstable basement may cause tumbling of the whole coral and subsequent pillar growth at approximately right angles to old columns. This process may be repeated, resulting in the formation of a third generation of pillars.