Daily colour changes associated with the fiddler crab, Uca capricornis

The purpose of this experiment was to examine the daily colour changes in relation to the tidal cycle in the fiddler crab, Uca capricornis. Experiments were conducted in the East Point Reserve, Darwin from Nov - Jan (04/05 & 05/06). \n\nTwenty-seven crabs (13 males, 14 females) were observed on the day after spring tide over several semilunar cycles. Digital photos of the crabs were taken before, during and after low tide. These photographs were examined for any changes in colour or pattern. \n\nUca capricornis do not regularly change their colouration over the course of the day. Of the 27 individuals observed, 24 did not noticeably change their colour, and none altered their pattern.

本实验旨在探究招潮蟹（Uca capricornis）的每日颜色变化与潮汐周期之间的关联。实验于11月至1月期间（2004/2005及2005/2006年度）在达尔文的东角保护区（East Point Reserve）开展。

在数个半太阴周期内，于大潮次日对27只招潮蟹（13只雄性、14只雌性）进行观察。在低潮前、低潮期间及低潮后拍摄了这些螃蟹的数码照片，并对照片中的颜色或图案变化情况进行检查。

招潮蟹（Uca capricornis）在日间并无规律性的颜色变化。在所观察的27只个体中，24只未出现明显的颜色变化，且所有个体均未改变其图案。