Almaco Jacks are strong fighters and good to eat, so they are always a welcome catch among Key West sport fishermen. The Almaco Jack is a member of the Jack family Carangidae, which also includes Yellowtail and Amberjack. Almaco Jacks look very similar to other Jacks, particularly the Greater Amberjack, which is common around Key West in some of the same habitats as the Almaco. However, the Almaco Jack has a deeper, more flattened body than other Jacks, and the first rays of the longest part of the dorsal fin are nearly twice as long as the dorsal spines. The dorsal and anal fins of the Alamco Jack are also more sickle-shaped than the fins of the Amberjack.
Almaco Jack (Seriola rivoliana)
Almaco Jacks are dusky-colored, sometimes with olive or lavender tones, and faint amber or olive stripes down their sides. The upper part of the body and the lower fins are usually dark brown or blue-green, with the belly much lighter and more brassy or lavender in color. Some fish have a dark bar running through the eye to the lower back, or an amber stripe extending from the eye back along the body. Almaco Jacks are typically around 3 feet long but may grow to 5 feet in length and up to 135 pounds.
Almaco Jack Habitat and Behavior
Alamco Jacks are widely distributed in tropical and temperate waters around the world. They live in the Western Pacific and Indian oceans, as well as around many of the Pacific islands. On the west coast of the USA, Almaco Jacks are found from California to Peru and the Galapagos Islands. In the western Atlantic Ocean, they range from Cape Cod to northern Argentina but are rare off of North and South Carolina.
Almaco Jacks can be found in small groups on slopes and off of reefs in water from 20 to 500 feet deep, and they occur around shipwrecks more often than most other Jacks. Almaco Jacks are rarely caught in inshore waters, and juvenile fish are often seen far offshore around floating debris and associated with Sargassum weed. Almaco Jacks have never been commercially harvested in significant numbers, so they are quite abundant throughout their range.
Almaco Jacks feed on small baitfish and squid during the day and night. They hunt in large schools and may drive baitfish into a ball then surround it and feed on the confused prey. Almaco Jacks are also grown in commercial open-water fish farms as an alternative to wild tuna for the Japanese sushi market. They have one of the best feed-conversion ratios of any fish, with only 1.6 to 2 pounds of feed required to produce 1 pound of fish. In one operation near the Island of Hawaii, the fish are produced under the brand name Kona Kampachi and raised in large diamond-shaped pens that are anchored to the seafloor 800 feet below. In 2008, global production reached 1,000,000 pounds.
The reproductive habits of the Almaco Jack are not well-documented. It is assumed that their spawning behaviors are similar to those of the closely-related Greater Amberjack. Spawning may occur offshore year-round depending on the latitude and water temperature.
Fishing for Almaco Jack
Almaco Jacks are rarely targeted specifically but are instead usually caught when fishing for other game fish including Amberjacks over deep reefs and wrecks, especially on the Atlantic side of Key West. They can most often be caught with squid tail jigs and other artificial baits that imitate squid or small fish, or small live baits fished at the depth where the fish are marked on the fish finder. Almaco Jacks and Amberjacks both are also very popular targets for spearfishermen.
They are very strong fighters and good to eat, so they are always a welcome catch among Key West sport fishermen. The Almaco Jack is considered to be a great table fish, with dense flesh that is quite similar to White Albacore Tuna when served as sushi. However, in some areas, the fish may have many parasites, which many people find to be unappetizing even though they are harmless to humans.