Pinnotheridae - Pea crabs

Pinnotheridae, the pea crabs, nearly all live in close physical association of other invertebrates, mainly in bivalve mollusk shells and in the tubes or burrows of marine worms or other organisms. Some are parasitic, but many are commensal (living along side their hosts for their own benefit but causing no harm to the host). They are small crabs, usually less than 1/2 in. in width. Many show sexual dimorphism, i.e., a distinct difference in size or appearance between the males and females. There are approximately 7 common species found in Texas.