AbstractRegeneration of autotomized limbs by third crab stageRhithropanoepus harrisiifollowed the all‐or‐none rule and was completed without significant alteration of the normal molt cycle. Loss of three to six primary limb buds during late intermolt or early premolt (D0, day 3) resulted in a delay of ecdysis while secondary limb buds were formed. The number of animals delaying ecdysis and producing secondary buds was stimulus dependent. While the number of animals initiating secondary regeneration increased with the number of primary buds lost, fewer animals in these groups were capable of regenerating all of the missing primary buds. Animals not initiating secondary regeneration or regenerating only some of the primary limb buds completed regeneration during the following molt cycle. The duration of the subsequent molt cycle was significantly shorter for all regenerating animals, including the regeneration control group. Partial regeneration and acceleration of subsequent molts appears to be the best allocation of available energy reser