抄録
<jats:p>1. We explored the mechanisms determining age and size at juvenile migration in brown trout <jats:italic>Salmo trutta</jats:italic> L. A <jats:sup>133</jats:sup>Cs tracer methodology was used to estimate food consumption of juvenile brown trout in a Norwegian stream, and the energy budgets of early migrants and stream residents were compared.</jats:p><jats:p> <jats:bold>2.</jats:bold> Fast‐growing brown trout migrated to the lake earlier and at a smaller body size than slower‐growing individuals. The 2+ migrants were significantly larger than those that remained 1 or more years longer in the stream. The 3+ migrants were significantly larger than the 2+ migrants. Some fast‐growing males matured in the stream, whereas all females left the stream before maturing sexually.</jats:p><jats:p> <jats:bold>3.</jats:bold> The food consumption and the energy budgets for 2+ migrants were more than four times higher than those of the resident 2+ fish. Total energy allocated to growth was also higher among migrants, and the total metabolic costs were five times higher among migrants than among resident fish.</jats:p><jats:p> <jats:bold>4.</jats:bold> The proportional energy allocation to growth among the 2+ migrants was much lower (about half) than that of those remaining longer in the stream. The reduction in the proportion of energy available for growth from age 1+ to 2+ was larger among migrants (88%) than among resident fish (68%). Reduction in the proportion of energy available for growth is a probable explanation for why migrations are initiated at age 2.</jats:p><jats:p> <jats:bold>5.</jats:bold> Our study supports the hypothesis that fast‐growing individuals shift their niche earlier and at a smaller body size than slower‐growing individuals because they maintain higher metabolic rates and are energetically constrained at a younger age by limited food resources than slow growers.</jats:p>
収録刊行物
-
- Journal of Animal Ecology
-
Journal of Animal Ecology 68 (4), 783-793, 1999-07
Wiley
- Tweet
詳細情報 詳細情報について
-
- CRID
- 1364233271150522112
-
- NII論文ID
- 30014800991
-
- ISSN
- 13652656
- 00218790
-
- データソース種別
-
- Crossref
- CiNii Articles