FAILURE OF LIMB SEGMENTS IN THE BLUE-CRAB, CALLINECTES-SAPIDUS (CRUSTACEA, MALACOSTRACA)

1. Critical forces, stresses and failure mode were determined for meru s and dactylus segments of blue crab walking legs loaded in bending, t he first such measurements for an animal with an exoskeleton. 2. 90% o f the segments failed by local buckling. 3. Mean force at failure for the merus was 60% higher than that for the dactylus, but calculated pe ak stresses were only one sixth as large. 4. Blue crabs are unlikely t o ever load their limbs sufficiently during normal activities as to ri sk failure of undamaged limb segments.