The king mackerel (Scomberomorus cavalla) is a migratory species of mackerel that lives its entire life in the open waters of the western Atlantic Ocean and Gulf of Mexico. It is an important species to both the commercial and recreational fishing industries.
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. Fish under 10 pounds (5 kg) show yellowish brown spots on the flanks, somewhat smaller than the spots of the Atlantic Spanish mackerel
, Scomberomorus maculatus
. Its cutting edged teeth are large, uniform, closely spaced and flattened from side to side. These teeth look very similar to those of the bluefish
, Pomatomus saltatrix
Distribution and habitat
The king mackerel is a sub-tropical species of the Atlantic Coast of the Americas. Common in the coastal zone from North Carolina
, 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.
King mackerel commonly occur in depths of 40 to 150 feet (12–45 m), where the principal fisheries occur. Larger kings (heavier than 20 lb or 9 kg) often occur inshore, in the mouths of inlets and harbors, and occasionally even at the 600 foot (180 m) depths at the edge of the Gulf Stream.
At least two migratory groups of king mackerel have been found to exist off the American coast. A Gulf of Mexico
group ranges from the Texas
coast in summer to the middle-east coast of Florida
from November through March. Spawning occurs throughout the summer off the northern gulf coast.
An Atlantic group is abundant off North Carolina in spring and fall. This group migrates to southeast Florida where it spawns from May through August, and slowly returns through summer. Apparently, this group winters in deep water off the Carolinas, as tagging studies have shown they are never found off Florida in winter.
Eggs and sperm are shed into the sea and their union is by chance. Depending on size, a female may shed from 50,000 to several million eggs over the spawning season. Fertilized eggs hatch in about 24 hours. The newly hatched larva is about 0.1 inches (2.5 mm) long with a large yolk sack. Little is known about king mackerel in their first year of life. Yearling fish typically attain an average weight of 3 to 4 pounds (1.4–1.8 kg) and a fork length of 25 inches (60 cm). At age seven, females average 21 lb (9.5 kg), males 11 lb (5 kg). King mackerel may attain 90 lb (40 kg), but any over 15 pounds (7 kg) is almost certainly a female.
King mackerel are voracious, opportunistic carnivores. Their prey depends on their size. Depending on area and season, they favor menhaden
and other sardine
-like fish (Clupeidae
), jacks (Scombridae
), grunts (Haemulidae
), striped anchovies (Engraulidae
),Cigar minnows, threadfin,northern mackerel and (blue runners
Fishing gear and methods
King mackerel are among the most sought-after gamefish throughout their range from North Carolina to Texas. They are taken mostly by trolling, using various live and dead baitfish, spoons, jigs and other artificials. Commercial gear consists of run-around gill nets. They are also taken commercially by trolling with large planers, heavy tackle and lures similar to those used by sport fishers. Typically when using live bait, two hooks are tied to a strong metal leader. The first may be a treble or single and is hooked through the live bait's nose and/or mouth. The second hook (treble hook) is placed through the top of the fish's back or allowed to swing free. When trolling for Kings using this method, it is important to make sure the baitfish are swimming properly. Typical tackle includes a conventional or spinning reel capable of holding 400 yards (370 m) of 20 lb (9 kg) test monofilament and a 7 foot (2.1 m), 20 pound (9 kg) class rod.
King mackerel are known throughout the sportfishing world for their blistering runs. For that, tournament series' have found success promoting events for this species. The most notable organizations to promote these events are the Southern Kingfish Association (SKA) and the FLW Outdoors tour. These events have been covered and reported by in several outdoor publications both in print and online.
Nutrition and processing
As of 2005, king mackerel are primarily marketed fresh. They may be sold as fillets, steaks, or in the round (whole). Their raw flesh is grayish, due to its high fat content, They are best prepared by broiling, frying, baking or, especially for large "smoker" king, by smoking.
According to the EPA
, king mackerel is one of the four fish (with swordfish
, and tilefish
,) children and women of child-bearing age should avoid due to high levels of methylmercury
found in these fish.
(See mercury poisoning
for more details.)
Small king mackerel are similar in appearance to Atlantic Spanish mackerel
, Scomberomorus maculatus
, and Cero, Scomberomorus regalis
, all three species being similar in shape and coloration. They may be distinguished as follows:
The lateral line on Atlantic Spanish mackerel and Cero slopes gradually from the top edge of the gill to the tail. In contrast that of the king mackerel takes an abrupt drop at mid-body (see illustration).
The first (spiny) dorsal fin on Atlantic Spanish mackerel and Cero has a prominent black patch. The king mackerel does not. As all three species normally keep the first dorsal folded back in a body groove, this difference is not immediately evident.
Atlantic Spanish mackerel have prominent yellow spots on the flanks at all sizes. In addition to such spots, Cero have one or more yellow stripes along the centerline. Young king mackerel have similar, but slightly smaller spots, these fade away on individuals weighing over 10 pounds (5 kg), but may still be seen as slightly darker green spots toward the back from some angles of view.
World wide, there are many fish quite similar to one or another of these three species. Off Mexico, Atlantic Spanish mackerel may be confused with Serra Spanish mackerel, Scomberomorus brasiliensis.