Planulation in the Scleractinian Coral Pocillopora damicornis in Singapore Waters

Temporal patterns in the planulation of the scleractinian coral, Pocillopora damicornis (Linnaeus 1816), common on Singapore reefs were observed from August to November 1990.Widely distributed throughout the Indo-Pacific, the species is known to release planula larvae after internal fertilisation.At any one time, six colonies collected from the field were maintained in clear, sheltered outdoor aquaria and daily planula counts observed.Planulation was observed to be directly influenced by the lunar cycle, commencing 2 to 3 days before the new moon, peaking at around the new moon and ending close to the first quarter.This periodicity is similar to the planulation patterns observed in P. damicornis populations of the Central Pacific, particularly those of Palau, as well as the populations in the Great Barrier Reef during the Austral summer.