Abstract
When pieces of the staghorn coral Acropora acuminata are incubated with 14C-urea, the label is incorporated into skeletal carbonate. Incorporation of this label differs from that of H14CO -3 , suggesting urea is not immediately hydrolysed to provide a further source of HCO -3 . The effects of certain organic substrates upon calcification suggest the ornithine cycle is involved. Citrulline, an ornithine cycle intermediate, is found in high concentrations in the tissues of hermatypic corals. Urea, allantoins, NH3 and arginine are also present. These compounds are barely detectable in zooxanthellae or an ahermatypic coral. The allantoins may be present as calcium salts. It is suggested that allantoins are the medium by which Ca2+ and CO2 are transported to sites of calcification. Hydrolysis of urea, formed by breakdown of allantoins, yields CO2 and NH3. The NH3 may neutralise protons formed during precipitation of CaCO3 and bring about their removal from sites of calcification. As well as providing urea, the ornithine cycle may also be involved in the removal of NH3 from sites of calcification.
Similar content being viewed by others
Literature Cited
Balagura, S. and R.F. Pitts: Excretion of ammonia injected into renal artery. Am. J. Physiol. 203, 11–14 (1962)
Barnes, D.J. and D.L. Taylor: In situ studies of calcification and photosynthetic carbon fixation in the coral Montastrea annularis. Helgoländer wiss. Meeresunters. 24, 284–291 (1973)
Bieleski, R.L. and N.A. Turner: Separation and estimation of amino acids in crude plant extracts by thin-layer electrophoresis and chromatography. Analyt. Biochem. 17, 278–293 (1966)
Bolland, E.G., A.R. Cook and N.A. Turner: Urea as a sole source of nitrogen for plant growth. I. The development of urease activity in Spirodela oligorrhiza. Planta 83, 1–12 (1968)
Campbell, J.W., R.D. Drotman, J.A. McDonald and P.R. Tramell: Nitrogen metabolism in terrestrial invertebrates. In: Nitrogen metabolism and the environment, pp 1–54. Ed. by J.W. Campbell and L. Goldstein. London & New York: Academic Press 1972
— and K.V. Speeg: Ammonia and biological deposition of calcium carbonate. Nature, Lond. 224, 725–726 (1969)
Conway, E.J.: Microdiffusion analysis and volumetric error, 467 pp. London: Crosby-Lockwood 1957
Dixon, M. and E.C. Webb: Enzymes, 950 pp. London: Longmans, Green & Co. 1964
Good, N., S. Izawa and G. Hind: Uncoupling and energy transfer inhibition in photophosphorylation. In: Current topics in bioenergetics, Vol. I. pp 75–112. New York & London: Academic Press 1966
Goreau, T.F.: The physiology of skeleton formation in corals. I. A method for measuring the rate of calcium deposition by corals under different conditions. Biol. Bull. mar. biol. Lab., Woods Hole 116, 59–75 (1959)
—: On the relation of calcification to primary productivity in reef building organisms. In: The biology of hydra, pp 269–285. Ed. by H.M. Lenhoff and W.F. Loomis. Miami: University Press 1961
— and N.I. Goreau: The physiology of skeleton formation in corals. II. Calcium deposition by hermatypic corals under various conditions in the reef. Biol. Bull. mar. biol. Lab., Woods Hole 117, 239–259 (1959)
Kanwisher, J.W. and S.A. Wainwright: Oxygen balance in some reef corals. Biol. Bull. mar. biol. Lab., Woods Hole 133, 378–390 (1967)
Lowry, O.H., N.J. Rosebrough, A.L. Farr and R.J. Randall. Protein measurement with the Folin phenol reagent. J. biol. Chem. 193, 265–275 (1951)
Morimoto, T. and R.E. Johnson: Ammonia and the regulation of acidity in human eccrine sweat. Nature, Lond. 216, 813–814 (1967)
Pearse, V.B.: Sources of carbon in the skeleton of the coral Fungia scutaria. In: Experimental coelenterate biology, pp 239–245. Ed. by H.M. Lenhoff, L. Muscatine and L.V. Davis. Honolulu: University of Hawaii Press 1971
— and L. Muscatine: Role of symbiotic algae (zooxanthellae) in coral calcification. Biol. Bull. mar. biol. Lab., Woods Hole 141, 350–363 (1971)
Roffman, B.: Patterns of oxygen exchange in some Pacific corals. Comp. Biochem. Physiol. 27, 405–418 (1968)
Simkiss, K.: Possible effects of zooxanthellae on coral growth. Experientia 20, p. 140 (1964a)
—: The inhibitory effects of some metabolites on the precipitation of calcium carbonate from artificial and natural sea water. J. Cons. perm. int. Explor. Mer 29, 6–18 (1964b)
Taylor, D.L.: Symbiotic pathways of carbon in coral reef ecosystems. Helgoländer wiss. Meeresunters. 24, 276–283 (1973a)
—: The cellular interactions of algal-invertebrate symbiosis. Adv. mar. Biol. 11, 1–56 (1973b)
Tramell, P.R. and J.W. Campbell: Carbamyl phosphate synthesis in invertebrates. Comp. Biochem. Physiol. 40B, 395–406 (1971)
Trench, R.K.: The physiology and biochemistry of zooxanthellae symbiotic with marine coelenterates. II. Liberation of fixed 14C by zooxanthellae in vitro. Proc. R. Soc. (Ser. B) 177, 237–250 (1971a)
—: The physiology and biochemistry of zooxanthellae symbiotic with marine coelenterates. III. The effect of homogenates of host tissues on the excretion of photosynthetic products in vitro by zooxanthellae from two marine coelenterates. Proc. R. Soc. (Ser. B) 177, 251–264 (1971b)
Vandermeulen, J.H., N.D. Davis and L. Muscatine: The effect of inhibitors of photosynthesis on zooxanthellae in corals and other marine invertebrates. Mar. Biol. 16, 185–191 (1972)
Waldi, D.: Spray reagents for thin-layer chromatography. In: Thin-layer chromatography, pp 483–502. Ed. by E. Stahl. New York & London: Academic Press 1965
Author information
Authors and Affiliations
Additional information
Communicated by G.F. Humphrey, Sydney
Rights and permissions
About this article
Cite this article
Crossland, C.J., Barnes, D.J. The role of metabolic nitrogen in coral calcification. Marine Biology 28, 325–332 (1974). https://doi.org/10.1007/BF00388501
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00388501