Nitrogenous waste excretion and accumulation of urea and ammonia inChalcalburnus tarichi (Cyprinidae), endemic to the extremely alkaline Lake Van (Eastern Turkey)
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The endemic, anadromous cyprinidChalcalburnus tarichi is the only fish species known to occur in alkaline Lake Van (Eastern Anatolia, Turkey). EightC. tarichi were maintained individually in Lake Van water (17 – 19°C; pH 9.8; 153 mEq·I−1 total alkalinity; 22‰ total salinity) and tank water samples analyzed for 24 h in 2 to 4 h intervals. At zero time, < 1µM ammonia was present and urea was undetectable in the tank water; at 24 h, total ammonia and urea made up 114±32 and 35±25µM, respectively. Over the experimental period, ammonia-N and urea-N excretion averaged 1041±494 and 607±169μmoles·kg−1 fish·h−1, respectively. The extent of urea excretion was highly variable between specimens. Uric acid excretion was not detectable.
Urea was present at high concentrations in all tissues and plasma (25 – 35μmoles·g−1·ml−1) of freshly caughtC. tarichi; total ammonia content of the tissues was by a factor of 1.9 (liver) to 3.0 (brain) lower. High arginase activity (2.4±0.2 U·min−1·g−1) was detected in the liver ofC. tarichi but ornithine carbamoylphosphate transferase, a key enzyme of the ornithine-urea-cycle, was absent. Ureagenesis is likely through degradation of arginine and/or uricolysis. High glutamine synthetase activity (11±0.6 U·min−1·g−1) and low ammonia content in brain suggest that, like other teleosts,C. tarichi has an efficient ammonia detoxification in the brain, but in no other tissue.
Nitrogenous waste excretion at alkaline pH is discussed. The ability ofC. tarichi to excrete high levels of ammonia at extremely alkaline pH is unique among teleosts studied so far. The mechanism of ammonia excretion under Lake Van conditions remains to be elucidated.
Keywordsteleost fishes excretion nitrogenous waste urea ammonia soda-lake adaptation enzyme activities GOT GPT GDH OCT arginase
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- Berg, L.S. 1964. Freshwater Fishes of the USSR and Adjacent Countries. Vol. II. 4th ed. Academy of Sciences of the USSR. Zoological Institute. (translated into English)Google Scholar
- Danalut, E. and Selcuk, B. 1992. Life history and environmental conditions of the anadromousChalcalburnus tarichi (Cyprinidae) in the highly alkaline Lake Van. Eastern Anatolia, Turkey. Archiv für Hydrobiol. (In press).Google Scholar
- Deyrolle, T. 1872. Notice sur une espèce remarquable de poisson qui vit dans les eaux du Lac de Van. Rev. Mag. Zool. (Paris). 2nde Sér. 23: 401–405.Google Scholar
- Emerson, K., Russo, R.C., Lund, R.E. and Thurston, R.V. 1975. Aqueous ammonia equilibrium calculations: Effect of pH and temperature. J. Fish. Res. Bd. Can. 32: 2379–2383.Google Scholar
- Forster, R.P. and Goldstein, L. 1969. Formation of excretory products.In Fish Physiology, Vol. 1. pp. 313–350. Edited by W.S. Hoar and D.J. Randall. Academic Press, New York.Google Scholar
- Gessner, F. 1957. Van Gölü. Zur Limnologie des großen Soda-Sees in Ostanatolien (Türkei). Arch. f. Hydrobiol. 53: 1–22.Google Scholar
- Grubinko, V.V., Yakovenko, B.V. and Yavonenko, A.F. 1987. Effects of starvation on arginase activity and urea contents in the carp,Cyprinus carpio. J. Ichthyol. 27: 107–110.Google Scholar
- Hauer, J. 1957. Rotatorien aus dem Plankton des Van-Sees. Arch. f. Hydrobiol. 53: 23–29.Google Scholar
- Haywood, G.P. 1983. Ammonia toxicity in teleost fishes. A review. Can. Tech. Rep. Fish. Aquat. Sci. 1177: 1–35.Google Scholar
- Kempe, S., Kazmierczak, J., Landmann, G., Konuk, T., Reimer, A. and Lipp, A. 1991. Largest known microbialities discovered in Lake Van, Turkey. Nature, Lond. 349: 605–608.Google Scholar
- Ladiges, W. 1960. Süßwasserfische der Türkei. i. Teil: Cyprinidae. Mitt. Hamburg. Zool. Mus. Inst. 58: 105–150.Google Scholar
- Love, R.M. 1980. The Chemical Biology of Fishes. Vol. II. Academic Press, London.Google Scholar
- Randall, D.J., Wood, C.M., Perry, S.F., Bergman, H., Maloiy, G.M.O., Mommsen, T.P. and Wright, P.A. 1989. Urea excretion as a strategy for survival in a fish living in a very alkaline environment. Nature, Lond. 337: 165–166.Google Scholar
- Sachs, L. 1974. Angewandte Statistik. Springer Verlag, Berlin.Google Scholar
- Schreckenbach, K., Spangenberg, R. and Krug, S. 1975. Die Ursache der Kiemennekrose. Z. Binnenfischerei DDR 22: 257–288.Google Scholar
- Smith, H.W. 1929. The excretion of ammonia and urea by the gills of fish. J. Biol. Chem. 81: 727–742.Google Scholar
- Vellas, F. and Serfaty, A. 1974. L'ammoniaque et l'urée chez un téléostéen d'eau douce: la carpe (Cyprinus carpio L.). J. Physiol., Paris 68: 591–614.Google Scholar
- Wright, P.A. and Wood, C.M. 1985. An analysis of branchial ammonia excretion in the freshwater rainbow trout: effects of environmental pH change and sodium uptake blockade. J. Exp. Biol. 114: 329–353.Google Scholar
- Wright, P.A., Randall, D.J. and Wood, C.M. 1988. The distribution of ammonia and H between tissue compartments in lemon sole (Parophrys vetulus) at rest, during hypercapnia and following exercise. J. Exp. Biol. 136: 149–175.Google Scholar
- Wright, P.A., Randall, D.J. and Perry, S.F. II 1989. Fish gill boundary layer: a site of linkage between carbon dioxide and ammonia excretion. J. Comp. Physiol. 158B: 627–635.Google Scholar