The truth is, crabs can regrow their claws. When a claw breaks, a hormone is released from the wound that causes them to shed their shells quickly and a new bud of a claw or claw will appear from within the new shell. The severed part of the claw heals into a fleshy lump that gradually reshapes the severed part, it curls up until it grows into other limbs as before, when the outer shell is hard enough, it will burst out into a new claw. However, this process can happen faster if the crab is young, when the environment is warm and they are fed well.

Based on this characteristic, to limit its movement, crab farmers often break off their claws and leave only one claw and one or two legs, immediately after that they will molt quickly to have new legs and claws.

Therefore, we always see crabs with two different sized claws, the smaller claw is the newly grown claw.

For this reason, in many countries, some crab species are “harvested” for their claws and then released back into the sea to grow their claws. However, when released into the sea, 50% will continue to live and grow their claws again, while the other 50% will die. It is not clear whether the reason for the death of those crabs is because their wounds cannot heal, or because they starve to death due to not having claws to find food or become food for others.

So you have the answer to the question “Why do crabs have bigger and smaller claws?”. Follow other articles in the “Science and Life” section to learn more useful and interesting information!