Does a crayfish turn blue after molting?

Yes, a crayfish can turn blue after molting due to the presence of a pigment called astaxanthin, which is usually masked by other pigments in their shell. During the molting process, the crayfish sheds its old exoskeleton and the new shell is initially soft and may appear blue before it hardens and the pigments stabilize. This blue coloration is often temporary, and as the shell hardens, the crayfish may return to its typical coloration.