Coral Reefs

, Volume 2, Issue 2, pp 91–100

Skeletal development inAcropora cervicornis

II. Diel patterns of calcium carbonate accretion
  • Elizabeth H. Gladfelter

DOI: 10.1007/BF02395279

Cite this article as:
Gladfelter, E.H. Coral Reefs (1983) 2: 91. doi:10.1007/BF02395279


Scanning electron microscopy, field studies using dyes which become incorporated into the skeleton of living corals as time markers, and petrographic and mineralogic techniques were used to describe the diel pattern of calcium carbonate accretion in the extending axial corallite ofAcropora cervicornis. The axial corallite extends by the formation of randomly oriented fusiform crystals at the distal tip of the branch. Morphological and mineralogical characteristics suggest that these might be calcite crystals. They form a framework upon which needle-like aragonite crystals (initially small tufts) begin to grow. As the needles elongate, groups of them form well defined bundles, fasciculi, which compose the primary skeletal elements. There is a diel pattern in the deposition of the skeleton. At night (1800–0600 hours) the distal spines are pointed and composed primarily of fusiform crystals. During the day (0600–1800 hours) mineral accretion occurs on all surfaces of the skeleton, apparently by epitaxial growth on the aragonite needles of the fasciculi.

Copyright information

© Springer-Verlag 1983

Authors and Affiliations

  • Elizabeth H. Gladfelter
    • 1
    • 2
  1. 1.West Indies LaboratorySt. Croix
  2. 2.Department of BiologyUniversity of CaliforniaLos AngelesUSA