Cod is the common name for about 150 species, including some of the most heavily harvested fish around the world. The Atlantic cod, living in vast shoals, may reach lengths of six feet (1.8 m) and weights of about 200 pounds (90 kg). They usually run between two and 25 pounds (1-11 kg). A single cod will lay up to nine million eggs in a season, eggs which float in the sea to be fertilized by the male. Many eggs are eaten by predators or carried away from the plankton on which the young fish feed. Fertilized eggs hatch in 10-20 days and the fish move to deeper water as they grow.