Evolution of intrinsic growth and energy acquisition rates.: II.: Trade-offs with vulnerability to predation in Menidia menidia
Evolution of intrinsic growth and energy acquisition rates.: II.: Trade-offs with vulnerability to predation in Menidia menidia
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DOI：
10.1111/j.0014-3820.2001.tb00836.x
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发表时间：
2001-09-01
期刊：
影响因子：
3.3
通讯作者：
Conover, DO
中科院分区：
文献类型：
--
作者：
Lankford, TE;Billerbeck, JM;Conover, DO
大西洋银汉鱼（Menidia menidia）表现出逆梯度纬度变化的体细胞生长率沿着北美东海岸。高纬度种群的幼虫和幼鱼表现出比低纬度种群基因型更高的能量消耗和生长的内在速率。在某些环境中，次最大增长的存在表明，权衡必须与能源和增长最大化的经常引用的理论利益相抗衡（例如，“越大越好，”“越快越好”）。我们假设，能源和增长的最大化权衡投资防御捕食者。我们进行了实验室选择实验，比较银汉鱼捕食的脆弱性：（1）快速增长的北方（新斯科舍省，NS）与缓慢增长的南方（南卡罗来纳州，SC）源种群;（2）表型操纵快速增长与中等增长的NS鱼;（3）最近喂养与未喂养的NS和SC鱼。测试涉及从常见的花园环境中绘制的鱼，并进行了混合处理学校的大小匹配的银鱼自然，常见的鱼类捕食者。NS银汉鱼的捕食死亡率显著高于SC银汉鱼。在生长的表型操作中也发现了类似的结果：在快速生长轨迹（类似于1.0毫米/天）上饲养的NS银鱼比那些以中等速度（类似于0.5毫米/天）生长的银鱼更容易被捕食。食物消耗也影响了对捕食者的脆弱性：在他们的胃里有大餐的银鱼比未进食的银鱼遭受了显着更高的捕食死亡率。捕食脆弱性的差异可能是由于游泳性能，而不是吸引捕食者。我们的研究结果表明，最大化的能量摄入和增长率产生健身成本的形式增加的脆弱性捕食。
The Atlantic silverside (Menidia menidia) exhibits countergradient latitudinal variation in somatic growth rate along the East Coast of North America. Larvae and juveniles from high-latitude populations display higher intrinsic rates of energy consumption and growth than genotypes from low-latitude populations. The existence of submaximal growth in some environments suggests that trade-offs must counter the oft-cited theoretical benefits of energy and growth maximization (e.g., "bigger is better,'' "faster is better") in the immature life stages. We hypothesized that energy and growth maximization trades off against investment in defense from predators. We conducted laboratory selection experiments to compare vulnerability to predation of silversides from: (1) fast-growing northern (Nova Scotia, NS) versus slow-growing southern (South Carolina, SC) source populations; (2) phenotypically manipulated fast-growing versus moderately-growing NS fish; and (3) recently fed versus unfed NS and SC fish. Tests involved fish drawn from common-garden environments and were conducted by subjecting mixed-treatment schools of size-matched silversides to natural, common piscine predators. NS silversides suffered significantly higher predation mortality than SC silversides. Parallel results were found in phenotypic manipulation of growth: NS silversides reared on a fast-growth trajectory (similar to1.0 mm/day) were significantly more vulnerable to predation than those growing at a moderate rate (similar to0.5 mm/day). Food consumption also affected vulnerability to predators: Silversides with large meals in their stomachs suffered significantly higher predation mortality than unfed silversides. Differences in predation vulnerability were likely due to swimming performance, not attractiveness to predators. Our findings demonstrate that maximization of energy intake and growth rate engenders fitness costs in the form of increased vulnerability to predation.