Variation of sperm allocation with male size and recovery rate of sperm numbers in spiny king crab Paralithodes brevipes
Variation of sperm allocation with male size and recovery rate of sperm numbers in spiny king crab Paralithodes brevipes
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短刺帝王蟹精子分配随雄性体型大小的变化及精子数量回收率
DOI：
10.3354/meps312189
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
S. Goshima
中科院分区：
文献类型：
--
作者：
Taku Sato;M. Ashidate;T. Jinbo;S. Goshima
这项研究调查了雄性的精子分配是否可以限制雄性的精子传给雌性，在有选择地捕捞大型雄性帝王蟹的种群中。我们通过实验研究了不同体型雄性在输精管中的精子回收率，不同体型雄性对不同体型雌性的精子分配，以及不同体型雄性在不同雌雄比例（1:1或1:6）下的精子分配情况。无论雄性大小如何，精子的恢复速度都非常缓慢，这表明精子分配策略对提高该物种的雄性繁殖成功率很重要。在体型较大的雄性中，射精量随着雌性体型的增加而显著增加，而体型较小的雄性的射精量则不随雌性体型的增加而变化，说明体型较小的雄性不能增加一定数量以上的射精量。雌性与小雄性交配的受精率明显低于与大雄性交配的受精率。在两个雄性体型类别中，雄性在不同性别比例之间的精子分配模式没有差异。这些结果表明，雄性平均体型的减少会增加雌性与小雄性交配的数量，而雌性的射精量却不能随着雌性体型的增加而增加，因此与小雄性交配的雌性精子供应不足，并且由于精子的限制而导致受精率低。
This study examined whether sperm allocation by males can limit sperm passed to females in fished spiny king crab populations in which large males are selectively fished. We in- vestigated the recovery rate of sperm in vasa deferentia of males of different body sizes, sperm allo- cation passed to females of different body sizes by males of different body sizes, and sperm allocation in different male:female sex ratios (1:1 or 1:6) by males of different body sizes by laboratory experi- ments. The recovery rates of sperm were very slow regardless of male size, suggesting that a sperm allocation strategy is important to increase male reproductive success in this species. In large males, the ejaculate size increased significantly with increasing female size, but the ejaculate size of small males did not vary with female size, indicating that small males cannot increase ejaculate size by more than a certain number. Females mated with small males showed significantly lower fertilization rates than females mated with large males. Males showed no difference in pattern of sperm alloca- tion between the different sex ratios in both male size classes. These results suggest that a decrease in mean male size due to male-only fishing would increase the number of females mated with small males without an ability to increase ejaculate size with increasing female size, so that females mating with small males would receive an insufficient sperm supply and have a low fertilization rate due to sperm limitation.