Coral morphology

Figure 10. SEM photographs of polished, etched thin sections of fossil Acropora palmata coral (after Edwards 1988). The scale bar in a is 10 microns, a depicts sample AFS-12, a last interglacial coral from Barbados. The crystal morphology in this well-preserved sample is indistingnishable from that of a modem sample (see Fig. 9b). The scale bar in b is 100 microns, b depicts sample PB-5B, a fossil coral collected from North Point Shelf on Barbados. The crystal morphology of this sample shows clear evidence of alteration, inclnding a large calcite crystal filling in a macroscopic pore (dark area in npper right portion of photograph).

Masters. P.M. and M.R. Zimmerman Age Determination of an Alaskan Mummy Morphological and Biochemical Correlation." Science, 2U1. 811-812 (1978). Moe, M.K. and S.P. Rosen Double-Beta Decay," Sci. Amer.. 48 (November 1989). Monastersky. K. "Coral Corrects Carbon Daring Problems, Science News, 356 (June 9, i 990). 

Lo, C.M., Morgan, J.A.T., Galzin, R. and Cribb, T.H. (2001) Identical digeneans in coral reef fishes from French Polynesia and the Great Barrier Reef (Australia) demonstrated by morphology and molecules. International Journal for Parasitology 31, 1573-1 578. 

Holmes, M.J., Gillepsie, N.C., and Lewis, R.J. 1988. Toxicity and morphology of Ostreopsis cf siamensis cultured from a ciguatera endemic region of Queensland, Australia. Proceedings of the 6th International Coral Reef Symposium 3 49-54. 

Stoddart, D.R., 1969. Ecology and morphology of recent coral reefs. Biol. Rev., 44 433-498. 

Lewis, M.S., 1968. The morphology of the fringing coral reefs along the east coast of Mahe, Seychelles. J. Geol., 76 140—153. 

Stoddard, D.R., 1971. Environment and history in Indian Ocean reef morphology. In D.R. Stoddard and M. Yonge (Editors), Regional Variation in Indian Ocean Coral Reefs. Symposia of the Zoological Society of London, No. 28, pp. 3—38. 

There have been no studies measuring both carbon and nutrient fluxes in different morphological zones, nor studies relating net carbon sources and sinks to nutrient fluxes. For many reefs, errors in gross production and respiration are too high (10-15%) to get reliable estimates of net community production (Crossland etal, 1991) while changes in nutrient concentrations are nearly undetectable. Such experimental restrictions have limited our ability to understand the relationship between carbon and nutrient cycles in coral reefs. 

Abstract This contribution summarizes the considerations that are of major importance in inorganic mineral formation before we look at specific biological minerals. Some factors which have to be taken into account (other than those that are well-known from inorganic (abiological) precipitations) are the nature of the biological organic matrix the restricted volume, outside or inside the cytoplasm, which can cause differences in impurity content (Mg) crystal morphology and isotopic fractionation. Cases such as those of corals, foraminifera and coccoliths are taken as examples. 

Most of the fossil corals from the Alakir Cay outcrops exhibit remarkable fossilization patterns from both morphological, microstructural and mineralogical view-points (summary in Cuif 1980). However, they have been submitted to mineralizing solutions crystallization of blocky calcite has occurred within the corallite internal cavities (Figs 4a-b). In spite of this crystallization process, fibrous aragonite is still well-preserved. For example, the average concentration of Sr is about 0.7% by weight (Fig. 4c), which is similar to the Sr concentration in recent coral fibres. Iron... 

CUIF, J. P. 1980. Microstructure versus morphology in the skeletons of Triassic scleractinian corals. Acta Palaeontologica Polonica, 25/3-4, 361-374. 

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