Lobster, fiddler crabs, hermit crabs,

Question

and certain shrimps have one claw larger than the other one. Of what significance is handedness in crustaceans?

Answer 1

The Male fiddler crab has an over-sized claw, which it uses in courtship and in fighting with another male. If a male loses his larger claw, the smaller one will begin to grow larger and the lost claw will regenerate into a new (small) claw. For at least some species of fiddler crabs, however, the small claw remains small, while the larger claw regenerates over a period of several molts, being about half its former size after the first molt.

The large claw can be either on the left or on  right. In addition, the small claw can become larger when the large claw is lost. So there is no handedness in fiddler crabs.