Some potentials and limits of the leucocrit test as a fish health assessment method

Journal of Fish Biology
By: , and 



The sensitivity of the leucocrit as a stress tolerance and fish health assessment method was evaluated by subjecting juvenile coho salmon, Oncorhynchus kisutch, or steelhead trout, Salmo gairdneri, to standardized crowding, handling, temperature and disease challenges. The leucocrit was a sensitive indicator of the physiological stress resulting from crowding at population densities of 0·2–0·4 kg l−1, and to the stress of handling and to temperature changes. It was relatively insensitive to physiological sampling procedures which supports its continued development as a stress assessment method.

In the case of fish diseases, subclinical or active Renibacterium salmoninarum and Yersinia ruckeriinfections had essentially no effect on leucocrit values. In contrast, active Aeromonas salmonicidainfections significantly depressed the leucocrit. However, no change was seen during the subclinical (incubation) phase prior to the development of an epizootic. Thus, the potential of the leucocrit as a fish health assessment method appears limited.

Publication type Article
Publication Subtype Journal Article
Title Some potentials and limits of the leucocrit test as a fish health assessment method
Series title Journal of Fish Biology
DOI 10.1111/j.1095-8649.1983.tb02948.x
Volume 23
Issue 6
Year Published 1983
Language English
Publisher Academic Press
Contributing office(s) Leetown Science Center, Western Fisheries Research Center
Description 6 p.
First page 711
Last page 716
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