Megalopa larva has a large un-segmented cephalothorax with all 13 pairs of appendages like those of a crab, abdomen is straight and in line with cephalothorax, it is like the abdomen of prawn with 6 pairs of well formed pleopods, In crabs the nauplius is passed in the egg, it hatches as a zoaea which by moulting forms the megalopa stage, the megalopa by moulting forms the adult.