Weapons or mating signals? Claw shape and mate choice in a fiddler crab
Weapons or mating signals? Claw shape and mate choice in a fiddler crab
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DOI：
10.1007/s00265-013-1541-6
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发表时间：
2013-07-01
影响因子：
2.3
通讯作者：
Backwell, Patricia R. Y.
中科院分区：
文献类型：
--
作者：
Callander, Sophia;Kahn, Andrew T.;Backwell, Patricia R. Y.
雄性通常拥有角、爪和獠牙等特征，这些特征在雄性与雄性之间的战斗中使用。研究表明，自然选择已经对这些武器进行了微调，以提高它们的效力，这些武器的形状为雄性提供了评估对手实力的线索。同样地，雌性也会评估雄性的武器来决定他作为配偶的价值。相对于身体大小最大的武器是雄性招潮蟹（招潮蟹属）的主要爪子。雄性使用它们的爪子作为武器和求爱信号，挥舞它来吸引雌性。我们使用机器人螃蟹在两个选择实验中测试女性交配偏好的基础上男性爪形状在Uca mjoebergi。首先，女性不喜欢同种爪的颜色和速度和模式的波动相匹配的任何三个替代形状的刺激。替代刺激是两种不同的异种爪和一个普通的矩形形状。第二，女性显着更喜欢的替代刺激时，他们提出了一个更快的波率。我们得出结论，爪形在U。mjoebergi并没有在雌性交配偏好所施加的性选择下进化，而更有可能是在雄性与雄性竞争中的有效性选择下进化的。
Males often possess traits, such as horns, claws, and tusks, which are used during male-male combat. Studies suggest that selection has fine tuned these weapons to improve their effectiveness and that the shape of these weapons provides cues for males to assess the strength of rivals. Similarly, females might also assess a male's weaponry to determine his value as a mate. The largest weapon relative to body size is the major claw of male fiddler crabs (genus: Uca). Males use their claws both as a weapon and as a courtship signal, waving it to attract females. We used robotic crabs in two-choice experiments to test female mating preferences based on male claw shape in Uca mjoebergi. First, females did not prefer conspecific claws over any of three alternatively shaped stimuli matched for color and for the rate and pattern of waving. The alternative stimuli were two different heterospecific claws and a plain rectangular shape. Second, females significantly preferred the alternative stimuli when they were presented at a faster wave rate. We conclude that claw shape in U. mjoebergi has not evolved under sexual selection imposed by female mating preferences and is more likely to have evolved under selection for effectiveness during male-male competition.