The use of claw colour and pattern for species recognition in the fiddler crab Uca mjoebergi

In the fiddler crab Uca mjoebergi, males attract females to their burrows by waving their enlarged yellow claw. Colour is clearly involved in species recognition in U. mjoebergi, but the role of the species-specific colour pattern has not been investigated. \n\nHere we show that U. mjoebergi females preferentially approach uniformaly yellow claws over bicoloured, yellow and white, claws. This is not due to a preference for a larger yellow signal, as they fail to discriminate between bicoloured claws differing in the proportion of yellow. Claw colour and pattern appear to be equally important in the recognition of conspecific males, as females do not distinguish between a uniformly coloured claw of the wrong colour and a claw containing yellow in the wrong pattern.\n\nExperiments were conducted in October 2005, near the mangrove boardwalk in the East Point Reserve, Darwin, NT.

莫氏招潮蟹（Uca mjoebergi）为招潮蟹的一类，雄性个体通过挥舞其特化增大的黄色螯足，将雌性吸引至自身洞穴中。颜色显然参与了莫氏招潮蟹的物种识别过程，但物种特异性体色模式所发挥的作用尚未得到研究。

本研究表明，莫氏招潮蟹的雌性个体更倾向于趋近通体黄色的螯足，而非黄白双色的螯足。这一偏好并非源于对更大面积黄色信号的偏爱，因为雌性无法区分黄色占比不同的双色螯足。螯足的颜色与模式在同种雄性识别过程中似乎同等重要：雌性无法区分颜色错误的纯色螯足，以及颜色模式错误的带黄色螯足。

本实验于2005年10月在澳大利亚北领地达尔文市东点保护区的红树林栈道附近开展。