REDUCTION OF TRIAENOPHORUS INFESTATION IN WHITEFISH BY DEPLETION OF THE CISCO POPULATION
In 1940 the catch of cisco in Lesser Slave Lake increased to over a million and a half pounds; it has remained at this high level for eight years, in the last two of which the catch has exceeded three million pounds. The age composition of the catch has decreased from nearly 80% six-year-olds or old...
| Published in: | Canadian Journal of Research |
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| Main Author: | |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
1948
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/cjr48d-007 http://www.nrcresearchpress.com/doi/pdf/10.1139/cjr48d-007 |
| Summary: | In 1940 the catch of cisco in Lesser Slave Lake increased to over a million and a half pounds; it has remained at this high level for eight years, in the last two of which the catch has exceeded three million pounds. The age composition of the catch has decreased from nearly 80% six-year-olds or older to nearly 80% two-year-olds. During the period 1944-1947 the number of Triaenophorus cysts in the whitefish has decreased from 265 per 100 fish (102.7 per 100 lb.) to 26 per 100 fish (6.8 per 100 lb.). This paper presents the evidence that indicates that this reduction of infestation in the whitefish has been a result of the depleted cisco population. |
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