Common names: Northern Kelp Crab, Shield-backed Kelp Crab This species was named after the shield-like shape of the carapace. Two shield-backed kelp crabs were found in the upper intertidal zone. One was found underneath the shade of a rock, about 4ft. wide, and another was found at the very bottom of a smaller tidepool, almost two feet wide. These pools were about 10ft. away from each other. The first crab that was spotted was in the bigger pool, it was a young one because it was a dark, olive green color. Adult shield-backed kelp crabs have some red and yellow on their bodies. The shield-shaped carapace on the first crab was about 3in. wide and each outstretched leg and claw added another inch across. This crab was sharing the large pool with many black turban snails and small hermit crabs. Many of the rocks surrounding the pool were covered with encrusting coralline algae. The crab was hiding under the shade of a rock, coming into the open every 8 min or so, and I saw it snap at a few hermit crabs a few times. For the most part, it was a solitary crab, in a pool by itself and it got a little territorial over its food and space. It was a calm, resting crab but only got excited when other species came close to it. The other shield-backed kelp crab in the smaller pool was also smaller in size. The carapace was only about 2in. across with another inch added because of the outstretched claws and legs. This crab was a littler further up the high intertidal zone from the first pool and was just walking around at the bottom of the pool. It was sharing the pool with a few snails but not nearly as much as the ones in the first pool. It walked slower and kept its arms out, not exerting too much energy. This crab also had a dark, olive green color.