California Code, Fish and Game Code - FGC § 8282

(a) Subject to this article and Article 1 (commencing with Section 9000) of Chapter 4, and subject to the regulation of the commission authorized under subdivision (c), rock crab may be taken in traps in any waters of the state at any time, except in Districts 9, 19A, 19B, and 21 and those portions of District 20 lying on the north and east sides of Santa Catalina Island north of Southeast Rock. Rock crab (Cancer antennarius), red crab (Cancer productus), or yellow crab (Cancer anthonyi), which is less than 4 1/4 inches, measured in a straight line through the body, from edge of shell to edge of shell at the widest part, shall not be taken, possessed, bought, or sold.

(b) Any person taking rock crab shall carry a measuring device and shall measure any rock crab immediately upon removal from the trap. If the person determines that the rock crab is undersize, the person shall return it to the water immediately.

(c) Upon the recommendation of the director regarding rock crab fishery management measures, and following a public hearing on the matter, the commission may adopt regulations to manage the rock crab resource consistent with Part 1.7 (commencing with Section 7050).