King Mackerel

INTRODUCTION

The king mackerel is a slender, very streamlined fish, flat from side to side with a tapered head. Its color ranges from an iridescent bluish green on its back to silver on its  sides. Two dorsal fins can fold back in to a groove to enhance speed, short pectoral fins on each side just behind the head; pelvic fins below the pectorals and a row of small fins extend from the dorsal and anal fins to the tail.

The king mackerel, or kingfish, is from three to five and one half feet in length and weighs as much as 100 pounds.

HABITAT AND DISTRIBUTION

Regional Occurrence

The king mackerel inhabits coastal waters from the Gulf of Maine south to Brazil, including the Gulf of Mexico and the Caribbean.  However, the coastal area between Maine and northern Florida is utilized only during the warmest summer months.  Large groups of king mackerel congregate along the coast of North and South Carolina throughout the spring, summer and fall of the year.  In southern and southeastern Florida, king mackerel are found year-round.  Large groups are also observed during summer months in northern areas of the Gulf of Mexico, from Texas through northwestern Florida.

It has been reported  that  two distinct populations of king mackerel apparently exist and migrate separately in the Gulf of Mexico and the western Atlantic.  One population, ranges from North Carolina through southeastern Florida, the other ranges from southeastern Florida throughout the northern Gulf of Mexico.  This group returns to southern Florida during winter months.  A third population ranges from the Western Gulf of Mexico through Texas and seasonally into Louisiana.

LIFE HISTORY

Age, Size, Lifespan

King mackerel live approximately 10 – 11 years.  Growth is variable in this species, with individuals of the same length sometimes differing markedly in age.  Females live longer than males and grow faster after the third year.  The oldest female collected was 14 years old and measured 4.6 feet.  The oldest male collected was 12 years old and measured 3.2 feet.

Reproduction

Male king mackerel mature by 4 years of age after reaching approximately 2.4 feet fork length (FL).  Most females mature by 1 year of age, or upon reaching approximately 14 inches FL Fecundity estimates in king mackerel are best correlated with weight King mackerel spawn in coastal waters off the Gulf of Mexico and South Atlantic and have an extended spawning season.  Larvae are most commonly collected in surface waters between May and October, peaking in September.  Larvae may be collected from northwestern Florida and Texas, as well as from Palm Beach through Cape Canaveral, Florida, Savannah, GA and Cape fear NC.  North of Cape Canaveral, larvae were generally found along the 200m depth contour of the continental shelf in the vicinity of the Gulf Stream.  Relatively few larvae are collected from either the eastern Gulf of Mexico south of the Yucatan, or from southeastern Florida.