The female lays hundreds of eggs. The female will hold the eggs under her long swimmeretes.
The eggs hatch in about 2-20 weeks. A small crayfish emerges which has all the same structures of an adult crayfish. The crayfish leaves its mothers protection in 1-2 weeks after it hatches from the egg. Many baby crayfish are eaten because they are so small.
The crayfish will grow and sheds its exoskeleton often. The process is called molting. A crayfish reaches adult size in 3-4 months & its life span is 3-8 years long. They grow old quickly.
The crayfish will either mate and start the process over again, or it will die.