The Relation between Capacity for Growth and Length of Growing Season: Evidence for and Implications of Countergradient Variation

摘要: Abstract Evidence suggests that the capacity for growth (i.e., maximum potential) within a species may vary inversely with length of growing season across latitudinal gradient. I evaluated this hypothesis data on three species—American shad Alosa sapidissima, striped bass Morone saxatilis, and mummichog Fundulus heteroclitus—having wide ranges (≈29–46°N) along east coast North America. For each these species, first decreases by factor about 2.5 increasing latitude species' range, yet body size at end is independent latitude. Northern fish must, therefore, grow substantially faster than do southern fish. This “countergradient variation” in rate be more widespread has been recognized. A similar pattern genetic basis Atlantic silverside Menidia menidia, salmon Salmo salar, lar...