Colour changes associated with moulting in the fiddler crab, Uca capricornis

The purpose of the experiment was to quantitatively examine the colour changes associated with moulting in the fiddler crab, Uca capricornis. Experiments were conducted in the East Point Reserve, Darwin between Nov - Jan (04/05 & 05/06). Circular cages were constructed on the mud flat and characteristically marked crabs were introduced. In total 11 females and 10 males were photographed through at least one moult.On average, U. capricornis grow 1.6mm with every moult. With every successive moult the carapace pattern contracts and becomes more distinct, especially in males. In addition to the considerable variation in pattern, both sexes also vary in the specific colour of their spots. Colour changes are associated with moulting and, as with pattern, tend to follow a certain progression.