This image is a study in primary color and texture, comparing appearances of adult crabs to their young. Within this one crevice, I found 12 crabs. Three of them are mature, while the other nine are immature. The adult crabs are a brilliant scarlet, orange and yellow. The juvenile crabs start out black, with small orange spots, and become more red as they grow and then discard their shells. The adults are predators, feeding on other crabs. They are called Sally Lightfoot Crabs because they appear to be walking on water as they glide from one rock to the another.