shape is extremely elongated and strongly compressed laterally.
Color distinguishes it from its relatives. It lacks the wavy
vertical lines found on the body of the wahoo and the pronounced
black spot on the front of the dorsal fin in the Spanish mackerel
and the cero. Body color is silvery-gray to iridescent green.
Young king mackerel have spots on their sides similar to Spanish
mackerel, but can be differentiated from the latter fish by
having a sharper bend in the lateral line midways down the
King mackerel are considered to be migratory fish, but a resident
population of large fish (commonly over 40 pounds) remains
year round in the northern Gulf of Mexico, off of Louisiana.
King mackerel in the eastern Gulf winter off of Florida and
in the summer migrate up the Florida coast to the northern
Gulf of Mexico, with some moving as far as Texas. Western
Gulf king mackerel move between Louisiana, Texas and Mexico,
spending their winter months in the south and summer in the
north. Waters off of Louisiana serve as a mixing ground for
eastern Gulf, western Gulf and large resident fish. King mackerels
can be found alone, but are usually in small groups.
King mackerel are aggressive, hard-hitting predators that
specialize in feeding on other fishes. By far the most common
fishes eaten are herrings, including menhaden and sardines.
These are followed by seatrout, primarily sand and silver
seatrout, and then various jacks. Other species are also eaten.
Researchers have found that most fish eaten by king mackerel
are less than 8 inches long, generally averaging 4-6 inches.
Surprisingly, the average size of fish eaten did not increase
in larger king mackerel. Non-fish food items make up only
a small amount of the diet, with shrimp being the leading
category. King mackerel can live to at least 14 years, although
most die earlier. Females grow larger than males and spawn
in their third or fourth year of life. Spawning takes place
in the warmer months.