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Use of Branchiostegal Rays to Determine Age of Lake Trout, Salvelinus namaycush (Walbaum)
Author(s) -
Bulkley Ross V.
Publication year - 1960
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1960)89[344:uobrtd]2.0.co;2
Subject(s) - salvelinus , trout , fish <actinopterygii> , biology , magnification , fishery , physics , optics
Abstract The ages of 342 lake trout from Fish Lake, Utah, and Lake Michigan were determined from branchiostegal rays. Most annuli were located without magnification. For back calculations of growth, rays were projected at a magnification of 3.4X. Evidence presented in support of the method includes agreement in size of ray and body size, agreement between number of annuli and size of fish, increase in new growth on rays as the growing season progressed, similarity of paired bones from the same fish, agreement between calculated and empirical lengths, and agreement in age with scale readings. Assigned age of 37 known‐age fish agreed with actual ages. The method is satisfactory for aging lake trout, but less satisfactory than the scale method for back calculations of growth.