The king mackerel is a medium-sized fish that typically weighs between 5 kg (11 lb) and 14 kg (30 lb), although some individuals can exceed 40 kg (90 lb). Its body is adorned with minuscule scales that are barely visible to the naked eye. The fish displays an olive coloration on its back, gradually fading to silver with a rosy iridescence on the sides, and eventually transitioning to white on the belly. In contrast, king mackerels under 5 kg (11 lb) exhibit yellowish-brown spots on their flanks, which are slightly smaller than those found on the Atlantic Spanish mackerel (Scomberomorus maculatus). Notably, the king mackerel possesses sharp, cutting-edged teeth that closely resemble those of the bluefish (Pomatomus saltatrix).
The king mackerel is a subtropical species found in the western Atlantic Ocean and the Gulf of Mexico. Its range spans from North Carolina to Brazil, occasionally reaching as far north as the Gulf of Maine and the eastern coast of India. However, the species shows a preference for water temperatures ranging from 20 to 29 °C (68 to 84 °F), which influences its distribution.
King mackerels are commonly found in depths of 12–45 m (40–150 ft), which coincide with the prime fishing areas. Larger individuals, weighing over 9 kg (20 lb), often venture inshore, seeking shelter in the mouths of inlets, harbors, and even at depths of 180 m (590 ft) near the edge of the Gulf Stream.
The migration patterns of king mackerel are closely tied to changes in water temperature and the availability of food sources. They exhibit a seasonal movement, heading northward during the summer months and southward in winter. These migrations are facilitated by their ability to swim in large schools. In the winter, both the South Atlantic and Gulf of Mexico stocks converge in a mixing zone near Monroe County, Florida, south of the Florida Keys, creating a remarkable spectacle between November and March.
Reproduction in king mackerel involves the release of eggs and sperm into the sea, where fertilization occurs by chance. During the spawning season, a female king mackerel can shed anywhere from 50,000 to several million eggs. Fertilized eggs typically hatch within 24 hours, giving rise to larvae measuring approximately 2.5 mm (0.098 in) in length. The early life stages of king mackerel remain relatively understudied. By the end of their first year, yearling fish generally weigh between 1.4 and 1.8 kg (3.1–4.0 lb) and have a fork length of about 60 cm (24 in). At the age of seven, females average 10 kg (22 lb), while males average 5 kg (11 lb). Although king mackerel have been known to reach weights of 40 kg (88 lb), individuals surpassing 7 kg (15 lb) are most likely females.
King mackerel are carnivorous predators with voracious appetites. Their diet varies depending on their size, location, and season. Among their preferred prey are squid, menhaden, jacks, cutlassfish, weakfish, grunts, striped anchovies, cigar minnows, threadfin, northern mackerel, and blue runners. It is important to note that king mackerel do not pose a threat to humans but will defend themselves if they perceive any threats, including instances where humans are flailing or thrashing in man-overboard situations.
King mackerel are highly sought-after gamefish in the coastal regions from North Carolina to Texas. Renowned for their incredible speed and powerful runs, they share similarities in performance with their distant relative, the wahoo. Anglers primarily target them through trolling techniques, employing various live and dead baitfish, spoons, jigs, and other artificial lures. Commercial fishing for king mackerel often involves run-around gill nets, while sport fishers utilize large planers, heavy tackle, and similar lures. When using live bait, a common technique involves attaching two hooks to a sturdy metal leader. The first hook, either a treble or single, is inserted through the live bait's nose or mouth, while the second hook (treble hook) is placed through the top of the fish's back or left to swing freely. This approach ensures effective hooking, particularly as king mackerel tend to target the tail section of baitfish. Successful tournaments and events organized by entities such as the Southern Kingfish Association (SKA) and the FLW Outdoors tour attest to the popularity of king mackerel as a sport fish.
Small king mackerel share similarities in appearance with the Atlantic Spanish mackerel (Scomberomorus maculatus) and the cero mackerel (Scomberomorus regalis). While these three species possess comparable shapes and colorations, several distinguishing features can help identify them:
Lateral Line: The lateral line of the Atlantic Spanish mackerel and the cero slopes gradually from the top edge of the gill to the tail. In contrast, the king mackerel's lateral line takes an abrupt drop at mid-body.
First Dorsal Fin: The first dorsal fin of the Atlantic Spanish mackerel and the cero boasts a prominent black patch, whereas the king mackerel lacks this feature. However, since all three species typically keep their first dorsal fins folded back in a body groove, this distinction may not be immediately noticeable.
Coloration: Atlantic Spanish mackerel exhibit prominent yellow spots on their flanks at all sizes, while cero mackerel possess one or more yellow stripes along their centerline. Young king mackerel also have similar, albeit slightly smaller, spots that fade away as individuals surpass 5 kg (10 lb). However, under certain viewing angles, slightly darker green spots may still be visible toward the back.
In conclusion, the king mackerel, or kingfish, captivates the imagination of commercial and recreational fishermen alike. With its impressive size, migratory patterns, and voracious feeding habits, this species is a prized catch. We hope this comprehensive guide has provided you with valuable insights into the captivating world of king mackerel. Whether you're an angler seeking an exhilarating fishing experience or an enthusiast seeking knowledge about this remarkable species, the king mackerel offers an abundance of opportunities to explore the bountiful waters of the western Atlantic Ocean and the Gulf of Mexico. Happy fishing!