Population dynamics and life history of a solitary coral, Balanophyllia elegans, from Central California

Abstract

Size-specific mortality rates and growth rates for the solitary coral Balanophyllia elegans are determined from size-frequency distributions of live corals from natural and artificial substrates, and from skeletons of dead corals found in rubble channels. Marked quadrats were monitored to measure actual recruitment and mortality for juveniles and adults. First year rate of mortality for juveniles is high, 56%; and mortality rate for adults is about 10% annually. Estimates of annual larval survivorship (44%) are incorporated in a life table, and other demographic parameters are calculated. B. elegans has a high intrinsic rate of increase apparently because of high larval survivorship and early onset of reproduction. Population growth is checked partly by high juvenile and random adult mortality. I estimate a 6-11 year average life span for B. elegans at the Hopkins Marine Life Refuge in Pacific Grove, California.