The brown crab lives along the Norwegian coast as far north as Troms County. It is most common at depths up to 50 m. The female crab has a broader apron than the male, whereas the male has a flatter carapace and larger claws. Normally, brown crabs spawn in the autumn after they have reached maturity at the age of roughly five years. The female crab carries the eggs around in her abdominal apron throughout the winter until they hatch in the summer. The crab larvae are pelagic, i.e. they swim around in the water for the first 4-6 weeks of their lives, before descending to the sea floor.