The king mackerel is a slender fish, only slightly compressed (flattened) from side to side. The entire body is covered with very small, hardly visible, loosely attached scales. The first (spiny) dorsal fin is entirely colorless and is normally folded back into a body groove, as are the pelvic fins. The lateral line starts high on the shoulder, dips abruptly at mid-body and then continues as a wavy horizontal line to the tail. Coloration is olive on the back fading to silver with a rosy iridescence on the sides, fading to white on the belly.
The king mackerel is a sub-tropical species of the Atlantic Coast of the Americas. Common in the coastal zone from North Carolina to Brazil, it occurs as far south as Rio de Janeiro, and occasionally as far north as the Gulf of Maine. Nonetheless, a preference for water temperatures in the range of 68 to 85 °F (20 to 29 °C). may limit distribution.
(source: wikipedia)