... region of the spectrum. Furthermore, the carapace colours of other species such as Tubuca (=Uca) flammula are sometimes exclusively red and black. It is possible that small variations in opsin ratios between cells, or a small subset of retinular cells with narrow band spectral sensitivity, could...

...Michael L. Walls; John E. Layne SUMMARY Foraging fiddler crabs ( Uca spp.) monitor the location of, and are able to return to, their burrows by employing path integration. This requires them to accurately measure both the directions and distances of their locomotory movements. Even though most...