Mortality surveys as a tool for studying marine anaemia in seapen-reared chinook salmon, Oncorhynchus tshawytscha (Walbaum)
| Autor: | C Stephen, C S Ribble |
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| Rok vydání: | 1997 |
| Předmět: | |
| Zdroj: | Aquaculture Research. 28:265-269 |
| ISSN: | 1365-2109 1355-557X |
| DOI: | 10.1046/j.1365-2109.1997.t01-1-00856.x |
| Popis: | Because of their rapid autolysis and post mortem contamination, the examination of dead seapen salmon has been considered of limited value for investigating disease in farmed salmon. Marine anaemia is a recently described plasmacytoid leukemia of farmed salmon that is diagnosed primarily by histological findings. The objectives of this study were to determine if marine anaemia could be reliably diagnosed in dead fish under commercial conditions and to identify the factors that affect the quality of data that are derived from mortality surveys. Surface moribund fish and dead salmon were recovered from four adjacent pens on 31 farm visits to commercial salmon farms over a 6-month period. Mortality surveys provided six times as many fish for gross pathological diagnosis and three times as many fish for reliable histological diagnosis of marine anaemia than did surveys of surface moribund salmon. The interval between recovery of dead fish from a pen most strongly influenced the quality of information derived from the mortality surveys. Mortality surveys proved to be more sensitive to finding the disease than did surface morbidity surveys. The results demonstrated that mortality surveys can provide reliable information, which can generate new insights not only into the impact and epidemiology of marine anaemia, but also for other fatal diseases of seapen salmon. |
| Databáze: | OpenAIRE |
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