This is my new friend Rockie the rock crab or to be more specific the Pacific rock crab or you could call him by his scientific name Cancer antennarius. He was picked up by a trap set by the Cabrillo Aquarium on their “See the Sea” trip on Saturday. The rock crab is in the family Cancridae along with the more famous dungeness crab that frequently ends up on dinner plates.
According to the book Pacific Coast Crabs and Shrimps by Gregory Jensen, rock crabs are usually found within depths of 150 feet. The rock crab in the photo was actually caught within the break wall of Long Beach Harbor, which to me is pretty amazing. The fact that anything can live in that water is pretty amazing. Granted the trap was set pretty close to the break wall, but still that’s not the cleanest water.
Male rock crabs can grow to be up to seven inches in size on a diet of mostly clams and mussels. These are good sized crabs. When I picked up Rockie I had to fully extend by hand to reach his shell on both sides and he was heavy. This family of big crabs may play an important role in the ocean ecosystem. According to Jensen, he has watched members of the Cancridae family rip open large horseclams while small bottomfish moved in to take bits of the feast. In his words: “By uncovering and opening such inaccessible prey, the crabs may function as a conduit for resources that would normally remain unavailable.” Excellent work rock crabs, way to share the wealth.
And for those of you in the Los Angeles area who love the ocean and marine life, I highly recommend any and all trips hosted by the Cabrillo Aquarium. You will learn a ton and have a blast!