You've ate it, maybe you haven't seen it, but you've heard of it. This is a Pacific Rock Crab. Every time you to to a Pacific Coast Tidepool from SF down to Monterey during the spring, there will be red and Pacific Rock Crabs everywhere.
Pacific Rock Crabs and Red Rock Crabs are a very unique type of crab. Like their cousins the Dungeness Crabs, they are fished by recreational crabbers. Unlike their relatives, they can sometimes be found in tidepools too.Their two claws can crush clams, hermit crabs and other crabs, which serve as their food. When the crabs mate in the spring, the male carries the female around until it molts (sheds skin.) These crabs are mostly brick red, except in juvenile stages. So why do you always miss them?
The answer is the sand. Most crabs in the Cancer family live underneath the sand. Juvenile Red Rock Crabs may have different color shells. Most Juvenile red rock crabs have white shells with stripes on them. Others are pure white or tinted blue/green.The color of a juvenile crab can determine the habitat the crab is living in. For instance, if a red rock crab's shell was brown, it may be living in a sandy area. That is so the shell of the crab blends in with the environment. If a juvenile crab is brick red like adults, it may be living in a rocky tidepool, where red alga covers the rock.
How does a red crab eat? Well, first, it uses it's antenna to detect the food. When a crab is buried, only it's eyes and antenna are sticking out. It will wait until the predator does not notice the crab. When the crab knows it's time, it will lunge towards the prey, and start nipping at it. These crabs eat very quickly, and may eat 4 tidepool eels in a day!
The Cancer Clan (red, yellow, Pacific rock crabs and Dungeness Crabs) pay a big role in our marine ecosystem. It keeps the snail and hermit crab population in check, and keeps the invasive European Green Crab (Carcinus maenas) from overpopulating. Remember this the next time you are eating a California Roll!
Every now and then, be sure to check your local tidepool for these crabs! They are quite common!
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