Latitudinal variation in fecundity among Arctic charr populations in eastern North America |
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| Authors: | M Power† J B Dempson‡ J D Reist§ C J Schwarz¶ G Power |
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| Institution: | Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada;, Fisheries and Oceans Canada, Science Branch, P. O. Box 5667, St John's, NL, A1C 5X1, Canada;, Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, MB, R3T 2N6, Canada;, Department of Statistics and Actuarial Science, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada and; 51 Glasgow Street, Conestogo, ON, NOB 1NO, Canada |
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| Abstract: | Variation in fecundity was examined from 32 populations of Arctic charr Salvelinus alpinus in eastern North America covering a range of 37° latitude and extending from Maine, U.S.A., to northern Ellesmere Island in the Canadian Arctic. Populations were classed as dwarf, normal or anadromous and covered a suite of different habitat and climatic regimes. Fecundity varied with fork length ( L F), with L F adjusted fecundity differing significantly among populations within each of the morphotypes implying that fecundity was a continuously responsive trait influenced by local environmental factors. Latitudinal variation in fecundity was also evident among morphotypes when the simultaneous effects of both latitude and L F were controlled. There was a significant trade‐off between fecundity and egg size in two of five populations of anadromous Arctic charr, but no evidence in limited data from either normal or dwarf populations. In contrast with some other studies of fecundity in salmonids, there was no evidence for a latitudinal cline in egg size. |
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| Keywords: | ecosystems/climate change egg diameter environmental influences fecundity latitude Salvelinus alpinus |
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