Fig. 3. The spectral signatures of U. vomeris carapace colours. (A) Photographs of male and female crabs, shortly after capture and after spectral reflectance measurements were taken using a fibre optics spectrograph (Ocean Optics USB2000) from two lateral and one central location on the blue-white carapace areas. Reflectance spectra for the same crabs are shown in (B), blue for males and purple for females.