Low Levels of Environmental Ammonia Increase Susceptibility to Disease in Chinook Salmon Smolts
Autor: | Beverly J. Wicks, Paige A. Ackerman, George K. Iwama, D. J. Randall |
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Rok vydání: | 2006 |
Předmět: |
Blood Glucose
Vibrio anguillarum Time Factors Hydrocortisone Physiology Biochemistry Fish Diseases Ammonia chemistry.chemical_compound Animal science Immune system Risk Factors Salmon White blood cell medicine Animals HSP70 Heat-Shock Proteins Respiratory Burst Dose-Response Relationship Drug biology Ecology biology.organism_classification Respiratory burst Dose–response relationship medicine.anatomical_structure chemistry Vibrio Infections Toxicity Muramidase Animal Science and Zoology Lysozyme |
Zdroj: | Physiological and Biochemical Zoology. 79:695-707 |
ISSN: | 1537-5293 1522-2152 |
Popis: | Ammonia criteria are established using data from standardized toxicity tests involving healthy animals. Both intrinsic and extrinsic environmental changes affect the immune system, but few toxicity studies consider the overall impact on this system and potential changes in resistance to infection. To investigate the effects of subacute levels of ammonia in coastal waters on physiological and immunological systems of fish, juvenile Chinook salmon were maintained in seawater (10 degrees C, pH 7.8) and exposed to two concentrations of ammonia, 2.5 and 10 mg/L total nitrogen. Both test levels resulted in increased internal levels of ammonia in the fish. Neither treatment level affected feeding rates. Over a time course of 10 d, numerous significant effects were observed. White blood cell counts changed significantly, as did respiratory burst activity, plasma lysozyme activity, and plasma glucose concentration in both treatments compared to controls. In an experimental infection with Vibrio anguillarum, fish previously exposed to subacute levels of ammonia were more susceptible to pathogenic challenge. The findings of this study indicate that a more thorough investigation into the effects of environmental ammonia on fish populations in coastal waters should be undertaken and the current environmental standards reassessed. |
Databáze: | OpenAIRE |
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