Why are reproductively parasitic fish males so small?–influence of tactic-specific selection
Why are reproductively parasitic fish males so small?–influence of tactic-specific selection
复制标题
为什么生殖寄生鱼雄性这么小？——特定策略选择的影响
DOI：
10.1007/s00114-010-0725-4
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发表时间：
2011
影响因子：
--
通讯作者：
Sato T
中科院分区：
文献类型：
--
作者：
Ota K;Kohda M;Sato T
尽管替代生殖策略广泛流行，但很少有人关注为什么生殖寄生雄性如此之小。在这项研究中，我们在贝壳育雏鱼Lamprologus callipterus 中解决了这个问题。这种鱼的“侏儒雄性”在一生中都比资产阶级同种小得多，并采用独特的寄生策略，即进入雌性产卵的腹足动物壳中，穿过雌性和壳壁之间的空间，并在产卵过程中留在雌性身后进行射精。在这里，我们通过种群间比较测试了这样的预测：它们仍然很小，可以穿过贝壳空间。我们发现，在不同种群中，性大小二态性存在负异速生长，雌性体型随着壳大小的增加呈指数增加，并且性大小二态性与壳大小之间呈负相关。这些结果表明，内部空间强烈调节矮小的雄性体型。我们得出的结论是，侏儒雄性的小身体是由于适应其独特的繁殖行为而产生的。
Despite the wide prevalence of alternative reproductive tactics, little attention has been paid to why reproductively parasitic males are so small. In this study, we tackled this issue in a shell-brooding fishLamprologus callipterus. Sneaky ‘dwarf males’ of this fish remain much smaller than bourgeois conspecifics throughout their life and employ a unique parasitic tactic, i.e. entering into a gastropod shell where a female is spawning, passing through the space between the female and shell wall and staying behind her to ejaculate throughout the spawning event. Here, we tested the prediction that they remain small to get past her through the shell spaces by interpopulation comparison. We showed, across populations, a negative allometry for sexual size dimorphism, an exponential increase of female size with an increase in shell size and a negative correlation between the magnitude of sexual size dimorphism and shell size. These results suggest that the inner spaces strongly regulate dwarf male size. We conclude that the small bodies of dwarf males arise from adaptation to their unique reproductive behaviour.