A baby crab is called a zoea. Female crabs lay bunches of eggs in the water. Once developed within the egg, the larvae-like zoea hatches. Zoea are microscopic and must go through several stages before reaching adulthood.
Each crab species has a unique number of zoeal stages. These stages are differentiated by moults, or shedding of the exoskeleton. The first major change is when the zoea moults into a megalops. During this stage, the baby crab resembles a lobster because of his protruding abdomen. After an additional moult, the crab is considered a juvenile. This is the stage during which the crab takes on adult features. This stage is complete when the crab reaches sexual maturity.