Abstract
Recent studies suggest a diurnal periodicity in the deposition of fusiform crystals by scleractinian corals. In order to check whether this is universally true in the Scleractinia, the surface structure of skeletons of Galaxea fascicularis (L.), collected at 3 h intervals over 1 day was observed with a scanning electron microscope. Fusiform crystals 0.3–3 μm wide and 0.5–5 μm long were found on the growing edges of septa of polyps collected at different times of day. There was no apparent diurnal change in the mean diameter of fusiform crystals. The size distributions of these crystals were almost the same by day (1200 h) and at night (2400 h). Small fusiform crystals which appeared to have been newly deposited were observed on septa collected both during the day and at night. The present study suggests that fusiform crystals are deposited continuously with no diurnal rhythm in G. fascicularis.
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Hidaka, M. Deposition of fusiform crystals without apparent diurnal rhythm at the growing edge of septa of the coral Galaxea fascicularis . Coral Reefs 10, 41–45 (1991). https://doi.org/10.1007/BF00301906
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DOI: https://doi.org/10.1007/BF00301906