Maternal and environmental gradients in the egg size of an iteroparous fish
Maternal and environmental gradients in the egg size of an iteroparous fish
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DOI：
10.2307/3071764
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发表时间：
2002-07-01
期刊：
影响因子：
4.8
通讯作者：
Leggett, WC
中科院分区：
文献类型：
--
作者：
Johnston, TA;Leggett, WC
生活史理论预测，生活在后代生长和生存条件相对较差的环境中的生物应该产生更少更大的后代。我们研究了卵的大小（后代大小的指数）的所有iteroparous，广播产卵，淡水鱼的海象（Stizostedion vitreum），从34个种群在260度的纬度，以确定是否卵的大小变化与内陆指数的少年栖息地质量。种群之间的变化（环境之间）进行了比较，种群内的变化（女性之间）。在种群内，卵子的大小通常随母体的大小和年龄而增加。这些关系的斜率在种群间的变异性（cv > 100%）比种群内的年际变异性（cv < 50%）大得多。卵大小与女性大小/年龄的相关性更强的人群更接近北方和南部界限的大眼范围。鸡蛋大小也与母亲的生长历史，但最近的增长（前一年）的影响是不一致的。卵大小的变化远小于同一种群的雌性之间的繁殖力。对于一个标准的大小/年龄的女性，预测的鸡蛋大小是更易变的群体之间（CV > 10%）比年际内的群体（CV < 5%），但只是略高于女性群体内的变化（平均CV = 8.5%）。尽管如此，卵大小的种群变异与环境条件有关。平均蛋大小随纬度的增加/年平均温度的降低而降低，与我们的预测相反。然而，正如预测的那样，鸡蛋的大小随着湖泊生产力的增加而下降，调整纬度/温度的影响。这些结果表明，在鱼类卵的大小可能会受到多种环境因素的影响，在人口，以及人口内的母体效应。
Life history theory predicts that organisms inhabiting environments with relatively poor conditions for the growth and survival of their offspring should produce fewer and larger offspring. We examined egg size (an index of offspring size) of all iteroparous, broadcast-spawning, freshwater fish-the walleye (Stizostedion vitreum)-from 34 populations across 26degrees of latitude in order to determine whether egg size varied with respect to environinental indices of juvenile habitat quality. Variation among populations (among environments) was compared to variation within populations (among females). Within Populations, egg size generally increased with maternal size and age. Slopes of these relationships were much more variable among populations (cv > 100%) than interannually within populations (cv < 50%). Egg size vs. female size/age correlations were stronger in populations closer to the northern and southern limits of the walleye range. Egg size was also related to maternal growth history, but the effects of recent growth (previous year) were inconsistent. Egg size varied much less than fecundity among females of the same Population. For a standard size/age of female, predicted egg size was more variable among populations (cv > 10%) than interannually within Populations (cv < 5%), but only slightly more variable than among females within populations (mean cv = 8.5%). Nevertheless, among-population variability in egg size was related to environmental conditions. Mean egg size decreased with increasing latitude/decreasing mean annual temperature, contrary to our predictions. However, as predicted, egg size decreased with increasing lake productivity following adjustment for the latitudinal/temperature effect. These results suggest that egg size in fishes may be influenced by multiple environmental factors across populations, as well as by maternal effects within populations.