Potential latitudinal variation in egg size and number of a geographically widespread reef fish, revealed by common-environment experiments
Potential latitudinal variation in egg size and number of a geographically widespread reef fish, revealed by common-environment experiments
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共同环境实验揭示了地理上广泛分布的珊瑚鱼的卵大小和数量的潜在纬度变化
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发表时间：
2003
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通讯作者：
T. Kokita
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作者：
T. Kokita
研究了分布于日本三个不同纬度的珊瑚鱼Pomacentus Coelstis(Pomacentus Coelstis(Pomacentridae))在野外和饲养种群中母体生殖特征的变化。野生鱼特定规格的窝卵数和窝卵重量随纬度的增加而增加。相反，在同一季节的比较中，野生鱼卵大小的纬度变化不明显，可能是因为温度对卵大小的影响。在三种温度下进行的普通环境实验表明，所有种群的卵大小都随着温度的升高而减小。在实验中，不同种群的卵大小、窝卵大小和窝卵重量在所有温度下都不同，表现出明显的纬向倾斜。来自低纬度的雌性在每个实验温度下都会产下更大的卵。来自高纬度的雌性个体特定大小的窝卵大小和体重更大。因此，北方鱼每次产卵的繁殖产量更大，产卵时产生的较小卵数也更多。这种鱼类的种群间变异可能部分是基于遗传的，尽管环境对这种变异的影响不能完全排除。这项研究通过普通环境实验，提供了沿海鱼类卵大小和数量可能存在纬度变化的证据。纬度与这些母体生殖特征之间的密切对应可能是当地适应的结果。
Variation in maternal reproductive traits was examined in field and reared populations of a geographically widespread reef fish, Pomacentrus coelestis (Pomacentridae), drawn from three different latitudes in Japan. Size-specific clutch size and clutch weight of wild fish increased with increasing latitude. Conversely, latitudinal variation in egg size of wild fish was obscure in same-season comparisons, probably because of the temperature effect on egg size. Common-environment experiments conducted at three temperatures showed that egg size decreased with increasing temperature in all populations. In the experiments, egg size, clutch size and clutch weight differed among populations at all temperatures, showing clear latitudinal clines. Females from low latitude spawned larger eggs at every experimental temperature. Size-specific clutch size and weight were greater in females from high latitude. Thus, the northern fish had a larger reproductive output per spawning and a larger number of smaller eggs in a spawning. Such interpopualtion variation in this fish is likely to be partially genetically based, although environmental effects on the variation cannot be entirely ruled out. This study provides evidence of potential latitudinal variation in the egg size and number in a coastal fish, by common-environment experiments. The close correspondence between latitudes and these maternal reproductive traits may be a consequence of local adaptation.