What Is the Crayfish's Hard Protective Covering?

Crustacean

• The crayfish is a crustacean like a lobster. Crustacean means that there is a rind or shell. Crustaceans are invertebrates, meaning they do not have a ventral heart or vertebral

  column. This is a single-celled organism.

Carapace

• The hard protective covering on a crayfish is a shell covering or shield. It is called a "carapace," which is a part of the exoskeleton that covers the thorax and head and protects the crayfish's lateral and dorsal surfaces. The exoskeleton doesn't get bigger as the animal grows. It is shed periodically, and the crayfish makes a new one. A crayfish can move even though the shell is hard, but the exoskeleton does limit growth, which is why the shell must be shed now and then, and a new one created. When the new shell generates, it is pliable and soft at first. If a crayfish has recently molted, it is referred to as a soft-shelled crab.

Molting

• The crayfish molts, which means it sheds its carapace when it outgrows it, and then generates a new one. When the molting occurs, the crayfish becomes soft and is at

  risk of ttack by other fish or other crayfish. It takes a few days for a new shell to completely harden and once again provide protection for the crayfish. Adult crayfish molt approximately twice a year, but babies molt a couple times a month.

Facts

• An interesting fact about crayfish is that they can be blinded or their eyesight damaged if they are exposed to direct sunlight. When a crayfish is damaged due to rough handling by divers, the crayfish may not go into its soft shell stage as it is supposed to do. It can take as much as three seasons for a damaged crayfish to recover and resume the molting process. However, it is vulnerable to predators during this time and probably won't survive. When the horns on the crayfish are broken, this is deadly for a crayfish because he needs the horns to detect movement.