Stress responses and disease resistance in salmonid fish: Effects of chronic elevation of plasma cortisol

Abstract

Basal levels of plasma cortisol in unstressed salmonid fish are normally in the range 0–5 ng ml−1. An acute stress such as handling or 1 h confinement caused a temporary elevation of the plasma cortisol levels of both brown trout,Salmo trutta L., and rainbow trout,Salmo gairdneri Richardson, in the range 40–200 ng ml−1 with a return to basal levels within 24–48 h. The extent of the cortisol elevation in response to an acute stress was dependent upon both the species and strain of trout. Chronic stresses, such as prolonged confinement or crowding, resulted in an elevation of plasma cortisol levels to approximately 10 ng ml−1. Under these circumstances, blood cortisol levels remained elevated for periods of up to 4 weeks before acclimation finally occurred.

It is shown, by means of intraperitoneal implantation of cortisol, that chronic elevation of plasma cortisol levels in the brown trout results in a dose-dependent increase in mortality due to common bacterial and fungal diseases. This effect is apparent at plasma cortisol levels as low as 10 ng ml−1, levels below those often reported as being representative of ‘unstressed’ fish. These findings are discussed in relation to the known immunosuppressive effects of corticosteroids in teleost fish.

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References cited

  1. Anderson, D.P., Roberson, B.S. and Dixon, O.W. 1982. Immunosuppression induced by a corticosteroid or an alkylating agent in rainbow trout (Salmo gairdneri) administered aYersinia ruckeri bacterin. Dev. Comp. Immunol. Suppl. 2: 197–204.

    Google Scholar 

  2. Bullock, G.L. and Stuckey, H.M. 1975.Aeromonas salmonicida: Detection of asymptomatically infected trout. Progve Fish-Cult. 37: 237–239.

    Google Scholar 

  3. Chilmonczyk, S. 1982. Rainbow trout lymphoid organs: Cellular effects of corticosteroids and anti-thymocyte serum. Dev. Comp. Immunol. 6: 271–280.

    PubMed  CAS  Article  Google Scholar 

  4. Donaldson, E.M. 1981. The pituitary-interrenal axis as an indicator of stress in fish.In Stress and Fish. pp. 11–47. Edited by A.D. Pickering. Academic Press, London.

    Google Scholar 

  5. Ellsaesser, C.F. and Clem, L.W. 1987. Cortisol-induced haematologic and immunologic changes in channel catfish (Ictalurus punctatus). Comp. Biochem. Physiol. 87A: 405–408.

    CAS  Article  Google Scholar 

  6. Ghoneum, M.H., Egami, N., Ijiri, K. and Cooper, E.L. 1986. Effects of corticosteroids on the thymus of the fishOryzias latipes. Dev. Comp. Immunol. 10: 35–44.

    PubMed  CAS  Article  Google Scholar 

  7. Houghton, G. and Matthews, R.A. 1986. Immunosuppression of carp (Cyprinus carpio L.) to ichthyophthiriasis using the corticosteroid triamcinolone acetonide. Vet. Immunol. Immunopathol. 12: 413–419.

    PubMed  CAS  Article  Google Scholar 

  8. Maule, A.G., Schreck, C.B. and Kaattari, S.L. 1987. Changes in the immune system of coho salmon (Oncorhynchus kisutch) during the parr-to-smolt transformation and after implantation of cortisol. Can. J. Fish. Aquat. Sci. 44: 161–166.

    CAS  Google Scholar 

  9. Pickering, A.D. and Christie, P. 1980. Sexual differences in the incidence and severity of ectoparasitic infestation of the brown trout,Salmo trutta L. J. Fish Biol. 16: 669–683.

    Article  Google Scholar 

  10. Pickering, A.D. and Duston, J. 1983. Administration of cortisol to brown trout,Salmo trutta L., and its effects on the susceptibility toSaprolegnia infection and furunculosis. J. Fish Biol. 23: 163–175.

    CAS  Article  Google Scholar 

  11. Pickering, A.D. and Pottinger, T.G. 1987. Lymphocytopenia and interrenal activity during sexual maturation in the brown trout,Salmo trutta L. J. Fish Biol. 30: 41–50.

    Article  Google Scholar 

  12. Pickering, A.D., and Pottinger, T.G. 1988. Lymphocytopenia and the overwinter survival of Atlantic salmon parr,Salmo salar L. J. Fish Biol. 32: 689–697.

    Article  Google Scholar 

  13. Pickering, A.D., Pottinger, T.G. and Christie, P. 1982. Recovery of the brown trout,Salmo trutta L., from acute handling stress: A time-course study. J. Fish Biol. 20: 229–244.

    Article  Google Scholar 

  14. Pickering, A.D., Pottinger, T.G. and Sumpter, J.P. 1987. On the use of dexamethasone to block the pituitary-interrenal axis in the brown trout,Salmo trutta L. Gen. Comp. Endocrinol. 65: 346–353.

    PubMed  CAS  Article  Google Scholar 

  15. Robertson, O.H., Hane, S., Wexler, B.C. and Rinfret, A.P. 1963. The effect of hydrocortisone on immature rainbow trout (Salmo gairdneri). Gen. Comp. Endocrinol. 3: 422–436.

    CAS  Article  Google Scholar 

  16. Roth, R.R. 1972. Some factors contributing to the development of fungus infection in freshwater fish. J. Wildl. Dis. 8: 24–28.

    PubMed  CAS  Google Scholar 

  17. Tripp, R.A., Maule, A.G., Schreck, C.B. and Kaattari, S.L. 1987. Cortisol mediated suppression of salmonid lymphocyte responsesin vitro. Dev. Comp. Immunol. 11: 565–576.

    PubMed  CAS  Article  Google Scholar 

  18. Wechsler, S.J., McAllister, P.E., Hetrick, F.M. and Anderson, D.P. 1986. Effect of exogenous corticosteroids on circulating virus and neutralizing antibodies in striped bass (Morone saxatilis) infected with infectious pancreatic virus. Vet. Immunol. Immunopathol. 12: 305–311.

    PubMed  CAS  Article  Google Scholar 

  19. Wedemeyer, G.A. and McLeay, D.J. 1981. Methods for determining the tolerance of fishes to environmental stressors.In Stress and Fish. pp. 247–275. Edited by A.D. Pickering. Academic Press, London.

    Google Scholar 

  20. Woodward, C.C. and Strange, R.J. 1987. Physiological stress responses in wild and hatchery-reared rainbow trout. Trans. Am. Fish Soc. 116: 574–579.

    Article  Google Scholar 

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Pickering, A.D., Pottinger, T.G. Stress responses and disease resistance in salmonid fish: Effects of chronic elevation of plasma cortisol. Fish Physiol Biochem 7, 253–258 (1989). https://doi.org/10.1007/BF00004714

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Keywords

  • stress response
  • pituitary-interrenal axis
  • cortisol elevation
  • Salmonidae
  • disease resistance
  • immunosuppression