DIURNAL PRODUCTIVITY AND APPARENT C-14 CALCIFICATION IN STAGHORN CORAL, ACROPORA-ACUMINATA

1. 1. The rate of 14C-fixation by Acropora acuminata tissues showed a marked increase after dawn. However, maximum 14C-fixation was not achieved until early afternoon. 2. 2. The apparent 14C-incorporation rate into the skeleton of whole branches reached a peak around noon. However, the major period of 14C-deposition occurred from noon to mid-afternoon. 3. 3. The broad peak of 14C-incorporation into skeleton of whole branches reflects two rate maxima; a late-morning maximum for zooxanthellae-free terminal calices, probably related to translocation of fixed carbon from basal tissues; and an early afternoon maximum for the zooxanthellae-containing basal areas of branches. © 1978.