Immature fish school, and sometimes mix with schools of Spanish mackerel of similar sizes. These mackerel appear to spawn over a protracted period, with several peaks. On the Atlantic coast, larvae have been collected from May through October. Larval distribution indicates that spawning occurs in the western Atlantic off the Carolinas, Cape Canaveral and Miami. There does not appear to be a well-defined area for spawning.
King mackerel prefer to consume fish but also have been known to eat shrimp and squid.
Female king mackerel can live for up to 14 years. Spanish Mackerel Spanish mackerel live in the coastal waters of the western Atlantic Ocean, from the Gulf of Maine to the Yucatan Peninsula. They are a schooling fish, preferring neritic, or shallow ocean coastal waters, but they freely enter tidal estuaries. The Spanish mackerel also has an elongated, compressed body and pointed snout, and is dusky blue dorsally with a silver underside. These mackerel are found most frequently in water temperatures between 70 and 88 degrees F, and rarely in waters below 64 degrees F. Spanish mackerel is a common visitor to the middle and lower Chesapeake Bay from spring to autumn, sometimes swimming as far north as the mouth of the Patuxent River.