Miss. Code Ann. § 49-15-89

It shall be unlawful for any person to catch, destroy, confine, hold or have in his possession, whether for individual use or for market, any of the genus callinectes sapidus (blue crab) or allied species, of a smaller size than five (5) inches measured from the tip of one (1) lateral spine across the back of the shell to the tip of the opposite lateral spine; provided that peeler crabs and soft-shell crabs are exempt from these limitations. Conservation officers may inspect any catch for violations of any of the provisions of Sections 49-15-83 through 49-15-91.