and the last shall be first heterochrony and compensatory marine growth in sea trout (salmo trutta)最后应当首先异时性和补偿性增长海洋海鳟(斑鳟属trutta).pdfVIP

And the Last Shall Be First: Heterochrony and Compensatory Marine Growth in Sea Trout (Salmo trutta) 1 2 ´ 1 3 Francisco Marco-Rius , Pablo Caballero , Paloma Moran , Carlos Garcia de Leaniz * ´ ´ ´ ´ ´ 1 Departamento de Bioquımica, Genetica e Inmunologıa, Universidad de Vigo, Vigo, Spain, 2 Consellerıa de Medio Rural, Servizo de Conservacion da Natureza, Xunta de Galicia, Pontevedra, Spain, 3 Department of BioSciences, Swansea University, Swansea, United Kingdom Abstract Early juvenile growth is a good indicator of growth later in life in many species because larger than average juveniles tend to have a competitive advantage. However, for migratory species the relationship between juvenile and adult growth remains obscure. We used scale analysis to reconstruct growth trajectories of migratory sea trout (Salmo trutta) from six neighbouring populations, and compared the size individuals attained in freshwater (before migration) with their subsequent growth at sea (after migration). We also calculated the coefficient of variation (CV) to examine how much body size varied across populations and life stages. Specifically, we tested the hypothesis that the CV on body size would differ between freshwater and marine environment, perhaps reflecting different trade-offs during ontogeny. Neighbouring sea trout populations differed significantly in time spent at sea and in age-adjusted size of returning adults, but not on size of seaward migration, which was surprisingly uniform and may be indicative of strong selection pressures. The CV on body size decreased significantly ov