| Autor: |
Caruso, D., Schlumberger, O., Dahm, C., Proteau, J-P. |
| Předmět: |
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| Zdroj: |
Aquaculture Research; Oct2002, Vol. 33 Issue 12, p999-1008, 10p |
| Abstrakt: |
Two experiments were conducted to assess plasma lysozyme levels, leucocrit and haematocrit in juvenile sheatfish (90-140 g) under experimentally induced stress and infection. Stress was provoked by random modification of environmental light for 15 min, 16 times a day with a halogen lamp (500 W) and by holding fish in a net for 3 min twice a day. In the first trial, repeated measuring of marked sheatfish showed a progressive significant decrease in plasma lysozyme level, a significant increase in leucocrit and a significant decrease in haematocrit. After a rest period of 1 week, only the leucocrit value was back to the prestress value. In the second trial, light-induced stress did not lead to any variation in lysozyme, leucocrit or haematocrit values. However, after intraperitoneal injection of Edwardsiella tarda (7 × 10[sup 8] cfu), a strong increase in plasmatic lysozyme in both stressed and unstressed groups of sheatfish was observed. The increase was significant vs. prechallenge levels 3 and 6 days after contamination, but no significant difference was detected between stressed and unstressed fish, despite the strongest stress (light + handling stress) applied to the fish at the beginning of contamination. Decreases in haematocrit values were observed in both groups of fish. A clear increase in leucocrit appeared in unstressed fish, whereas stressed fish showed a significant decrease in leucocrit values. Condition factor was significantly decreased by all kinds of stress. There were no difference in mortality between stressed and unstressed groups. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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