The "shell" of the crayfish, or rather its exoskeleton, is composed of the polysaccharide chitin and some lipids. There are also some calcium salts in the exoskeleton of the crayfish, which gives it its firmness.
Yes they do but they are not very big, It depends on how big the crayfish are.
Carapace
Chitin and some calcium
A rostrum on a crayfish is an extension of its shell. This part is used for extra protection.
An exoskeleton - i.e. a shell.
After it molts, a crayfish needs some time to grow a new and larger shell. During this time it has no shell to protect it from attack, therefore it hides.
hard shell, sharp claws aquatic
Crayfish are crustaceans, and therefore have a shell-like outer covering called an exoskeleton.
Nope. They have a shell, known as an exoskeleton. Means bones are on the outside (the shell takes the place of bones)
It's called 'calcification'
Crayfish shed their shells because they are growing. they do not shed their skin, but rather the inflexible shell on top. Because it is inflexible, it cannot grow with the crayfish and they have to make new ones. Replacing a shell is called "molting". crayfish and other crustaceans molt more when they are young and are growing faster. Hope this helps!