ENVIRONMENTAL SEX DETERMINATION IN SOUTHERN BROOK LAMPREY, ICHTHYOMYZON-GAGEI
ENVIRONMENTAL SEX DETERMINATION IN SOUTHERN BROOK LAMPREY, ICHTHYOMYZON-GAGEI
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DOI：
10.1139/f93-147
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发表时间：
1993-06-01
影响因子：
2.4
通讯作者：
BEAMISH, FW
中科院分区：
文献类型：
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作者：
BEAMISH, FW
研究人员测定了20个南溪七鳃鳗（lchthyomyzon gagei）幼虫种群的性别比例，这些幼虫是从美国东南部的大部分活动范围内收集的。男性的比例在9%到49%之间。不同的死亡率不太可能是一个因素，因为每个人口中各年龄组的性别比例相似。建议环境性别决定。性别比例随生长（以特定年龄的幼虫长度表示）、幼虫密度、pH值和出生流的年平均温度而变化。一般来说，在促进快速生长的条件下，雄虫百分率与密度成正比，与温度成反比。在生长缓慢的情况下，随着幼虫密度的增加，雄虫的比例下降，低ph值的响应小于高ph值的响应，温度对幼虫生长缓慢的影响不大。在其他类似的环境条件下，当生长迅速时，雄性的比例下降。
Sex ratios were determined for 20 populations of southern brook lamprey larvae, lchthyomyzon gagei, collected from throughout much of their range in the southeastern United States. Ratios varied between 9 and 49% males. Differential mortality was an unlikely factor, as sex ratios were similar among age groups within each population. Environmental sex determination is suggested. Sex ratio varied with growth (expressed as length of larvae at specific ages), larval density, pH, and annual mean temperature of the natal stream. Generally, under conditions promoting rapid growth, the percentage of males varied directly with density and inversely with temperature. Where growth was slow, the percentage of males declined as larval density increased, the response being less at low than at high pH. Temperature had little effect when larval growth was slow. The percentage of males declined when growth was rapid under otherwise similar environmental conditions.