Abstract
Using radio-isotopes, the turnover rates of sodium, chloride, water, and urea were measured, at different salinities, in the pyjama shark, Poroderma africanum (Gmelin). The exchangeable ionic space was also measured. Sodium turnover was 0.24%/h in normal sea water (467 mM Na/l, 550 mM Cl/l, 1020 m0sm/l), and under similar conditions, chloride, water and urea showed turnover rates of 2.47, 97, and 0.08%/h, respectively. Chloride and water turnover showed maximal values in normal sea water, and declined with variation of the medium away from this salinity, the decline in chloride turnover rate being more marked. Exchangeable ionic space was calculated, using Chloride-36, and was found to be 34.4% body volume or 32.4 ml/100 g fresh weight. Present results show that chloride turnover is about 10 times that of sodium; a relationship previously observed in other elasmobranchs. Water turnover rates are similar to those of other elasmobranch species, although urea turnover is somewhat lower. Salinity has a pronounced effect upon chloride and urea turnover rates.
Similar content being viewed by others
Literature Cited
Boylan, J.W.: Gill permeability in Squalus acanthias. In: Sharks, skates and rays, pp 197–206. Ed. by P.W. Gilbert. Baltimore: Johns Hopkins 1967
—: A model for passive urea reabsorption in the elasmobranch kidney. Comp. Biochem. Physiol. 42A, 27–30 (1972)
Burger, J.W. and D.C. Tosteson: Sodium influx and efflux in the spiny dogfish Squalus acanthias. Comp. Biochem. Physiol. 19, 649–653 (1966)
Carrier, J.C. and D.H. Evans: Ion, water and urea turnover rates in the nurse shark, Ginglymostoma cirratum. Comp. Biochem. Physiol. 41A, 761–764 (1972)
——: Ion and water turnover in the freshwater elasmobranch Potamotrygon. Comp. Biochem. Physiol. 45A, 31–44 (1973)
Chan, D.K.O., J.G. Phillips and I.C. Jones: Studies on electrolyte changes in the lip-shark, Hemiscyllium plagiosum with special reference to hormonal influence on the rectal gland. Comp. Biochem. Physiol. 23, 185–198 (1967)
Comar, C.L. (Ed.): Radioisotopes in biology and agriculture, 481 pp. New York: Mc Graw-Hill 1955
Goldstein, L.: Urea biosynthesis in elasmobranchs. In: Sharks, skates and rays, p. 212. Ed. by P.W. Gilbert. Baltimore: Johns Hopkins 1967
— and R.P. Forster: Osmoregulation and urea metabolism in the little skate, Raja erinacea. Am. J. Physiol. 220, 742–746 (1971)
Haywood, G.P.: Hypo-osmotic regulation coupled with reduced metabolic urea in the dogfish Poroderma africanum: an analysis of serum osmolarity, chloride, and urea. Mar. Biol. 23, 121–127 (1973)
Holmes, W.N. and E.M. Donaldson: The body compartments and distribution of electrolytes. In: Fish physiology, Vol. l. pp 1–89. Ed. by W.S. Hoar and D.J. Randall. New York: Academic Press 1969
Kempton, R.T.: Studies of the elasmobranch kidney-II. Reabsorption of urea by the smooth dogfish, Muetelus canis. Biol. Bull. mar. biol. Lab., Woods Hole 104, 45–56 (1953)
Kirsch, R.: Plasma chloride and sodium, and chloride space in the European eel, Anguilla anguilla L. J. exp. Biol. 57, 113–131 (1972)
Maetz, J.: Les échanges de sodium chez le poisson Carassius auratus L. Action d'un inhibiteur de l'anhydrase carbonique. J. Physiol., Paris 48, 1085–1099 (1956)
—: Mechanisms of salt and water transfer across membranes in teleosts in relation to the aquatic environment. In: Hormones and the environment, Ed. by G.K. Benson and J.G. Phillips. Cambridge: Cambridge University Press 1970
Maetz, J. et B. Lahlou: Les échanges de sodium et de chlore chez un elasmobranche, Scyliorhinus, mesurés à l'aide des isotopes 24 Na et 36 Cl. J. Physiol., Paris 58, p. 249 (1966)
Mayer, N. and J. Nibelle: Sodium space in freshwater and sea-water eels. Comp. Biochem. Physiol. 31, 589–597 (1969)
Payan, P., L. Goldstein and R.P. Forster: Gills and kidneys in ureosmotic regulation in euryhaline skates. Am. J. Physiol. 224, 367–372 (1973)
— et J. Maetz: Balance hydrique et minérale chez les elasmobranches: arguments en favour d'un contrôle endocrinien. Bull. Inf. Sci. Technol. C.E.A. 146, 77–96 (1970)
—: Balance hydrique chez les elasmobranches: arguments en favour d'un contrôle endocrinien. Gen. comp. Endocr. 16, 535–554 (1971)
—: Branchial sodium transport mechanisms in Scyliorhinus canicula: evidence for Na+/NH +4 and Na+/H+ exchanges and for a role for carbonic anhydrase. J. exp. Biol. 58, 487–502 (1973)
Pré, J., P. Giraudet et P. Cornillot: Ultramicrodétermination directe automatique et manuelle de l'urée dans les lquides biologiques. Path. Biol., Paris 16, 895–899 (1968)
Price, K.S.: Fluctuation in two osmoregulatory components, urea and sodium chloride of the clearnose skate Raja eglanteria. Bosc 1802-II Upon natural variations of the salinity of the external medium. Comp. Biochem. Physiol. 23, 77–82 (1967)
— and E.P. Creaser: Flucturations in two osmoregulatory components, urea and sodium chloride, of the clearnose skate Raja eglanteria. Bosc 1802-I Upon laboratory modification of external salinities. Comp. Biochem. Physiol. 23, 65–76 (1967)
Randall, D.J.: The circulatory system. In: Fish physiology, Vol. 4. pp 133–172. Ed. by W.S. Hoar and D.J. Randall. New York: Academic Press 1970
Schales, O. and S.S. Schales: A simple and accurate method for the determination of chloride in biological fluids. J. biol. Chem. 140, 879–884 (1941)
Thorson, T.B.: Measurement of the fluid compartments of four species of marine chondrichthyes. Physiol. Zoöl. 31, 16–23 (1958)
—: The partitioning of body water in osteichthyes: Phylogenetic and ecological implications in aquatic vertebrates. Biol. Bull. mar. biol. Lab., Woods Hole 120, 238–254 (1961)
de Vlaming, V.L. and M. Sage: Osmoregulation in the euryhaline elasmbranch Dasyatis sabina. Comp. Biochem. Physiol. 45A, 31–44 (1973)
Author information
Authors and Affiliations
Additional information
Communicated by J. H. S. Blaxter, Oban
Rights and permissions
About this article
Cite this article
Haywood, G.P. The exchangeable ionic space, and salinity effects upon ion, water, and urea turnover rates in the dogfish Poroderma africanum . Mar. Biol. 26, 69–75 (1974). https://doi.org/10.1007/BF00389088
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF00389088