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Age, growth, maturity, and fecundity of 'humper' lake trout, Isle Royale, Lake Superior

Transactions of the American Fisheries Society

Out-of-print
By:
DOI: 10.1577/1548-8659(1965)94[75:AGMAFO]2.0.CO;2

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Abstract

Humper lake trout are one of the several races or subpopulations of lake trout in Lake Superior. This study is based on 3,705 fish collected on a reef south of Isle Royale near the eastern end. The mean lengths of humper trout from commercial gill nets were smaller than those of lean lake trout. Members of age-groups VII, VIII, and IX represented 81.5 per cent of the commercial humper catch. The body-scale relation was described by two intersecting straight lines. The weight of humper trout increased as the 3.282 power of the length. Growth in length was slow and ranged from 1.6 to 3.5 inches per year. Annual increments were greatest in the first, sixth, and seventh years. Growth in weight was also slow but increased each year. Humper trout became legal (1 1/2 pounds) in the eighth year of life and reached 5 pounds in 11 years. All fish longer than 19.1 inches and older than age-group VIII were mature; the shortest mature fish were: males, 12.7 inches; females, 14.7 inches. At minimum legal size, 98 per cent of the males and 56 per cent of the females were mature. Humper trout produced an average of 1,351 eggs per fish or 516 per pound.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Age, growth, maturity, and fecundity of 'humper' lake trout, Isle Royale, Lake Superior
Series title:
Transactions of the American Fisheries Society
DOI:
10.1577/1548-8659(1965)94[75:AGMAFO]2.0.CO;2
Volume
94
Issue:
1
Year Published:
1965
Language:
English
Publisher:
Taylor & Francis
Publisher location:
London, UK
Contributing office(s):
Great Lakes Science Center
Description:
9 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Transactions of the American Fisheries Society
First page:
75
Last page:
83