Big mamas matter for fish The theoretical relationship between reproduction and body size has assumed that total mass relates directly to fecundity, regardless of the number of individuals involved. This assumption leads to fisheries management practices that suggest that one large female fish can be replaced by several smaller females. However, this assumption is incorrect. Barneche et al. show that larger females are far more productive than the same weight's worth of smaller females. Management practices that ignore the value of large females could contribute to unexplained declines seen in some fish stocks. Science, this issue p. 642 Reproduction does not scale linearly with body size in fish—bigger females produce many more offspring. Body size determines total reproductive-energy output. Most theories assume reproductive output is a fixed proportion of size, with respect to mass, but formal macroecological tests are lacking. Management based on that assumption risks underestimating the contribution of larger mothers to replenishment, hindering sustainable harvesting. We test this assumption in marine fishes with a phylogenetically controlled meta-analysis of the intraspecific mass scaling of reproductive-energy output. We show that larger mothers reproduce disproportionately more than smaller mothers in not only fecundity but also total reproductive energy. Our results reset much of the theory on how reproduction scales with size and suggest that larger mothers contribute disproportionately to population replenishment. Global change and overharvesting cause fish sizes to decline; our results provide quantitative estimates of how these declines affect fisheries and ecosystem-level productivity.

中文翻译：

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鱼的生殖能量输出与体型不成比例地增加

大妈妈对鱼很重要 繁殖和体型之间的理论关系假设总质量与繁殖力直接相关，而不管涉及的个体数量如何。这一假设导致渔业管理实践表明，一条大型雌性鱼可以被几条较小的雌性鱼取代。然而，这个假设是不正确的。巴内什等人。表明体型较大的雌性远比同等重量的体型较小的雌性高得多。忽视大型雌性价值的管理做法可能导致某些鱼类种群出现无法解释的下降。科学，这个问题 p。642 繁殖并不与鱼的体型成线性比例——较大的雌性会产生更多的后代。体型决定了总的生殖能量输出。大多数理论假设生殖产出是固定的大小比例，相对于质量，但缺乏正式的宏观生态测试。基于该假设的管理可能会低估较大的母亲对补给的贡献，从而阻碍可持续收获。我们通过对生殖能量输出的种内质量缩放进行系统发育控制的荟萃分析，在海洋鱼类中测试了这一假设。我们表明，不仅在繁殖力方面，而且在总生殖能量方面，体型较大的母亲比体型较小的母亲繁殖得更多。我们的结果重置了关于繁殖如何随体型成比例的大部分理论，并表明体型较大的母亲对种群补充的贡献不成比例。全球变化和过度捕捞导致鱼类尺寸下降；