Fig. 5. Rapid, stress-related changes of carapace colours in Uca vomeris. The reflectance measurements in (A) and (B) were made about 1 min before the colour photographs were taken at different times after capturing a female and a male crab. Measurements were taken using a fibre optics spectrograph (Ocean Optics USB2000) from three points on the posterior carapace. The brilliant blue colours change to a dull, dark blue within 15–20 min of capture.