Almaco Jack

The Almaco Jack (Seriola rivoliana) is a member of the jack family Carangidae, found in tropical and subtropical waters worldwide, including the Atlantic, Indian, and Pacific Oceans. It belongs to the genus Seriola alongside the greater amberjack and yellowtail, but is distinguished by its deeper body and tall, elongated dorsal and anal fin lobes. Almaco Jack are commonly associated with offshore reefs, rocky structure, and wrecks at moderate depths. The species is broadly distributed and supports recreational fisheries in several regions, with populations generally considered stable, though localized data can be limited in some parts of its wide range.

Almaco Jack reach 50-90 cm and are recognized by:

• A noticeably deep body compared to other Seriola species
• Tall, sickle-shaped dorsal and anal fins with elongated, trailing lobes
• Bronze to amber-brown coloration with a dark olive back and a faint dusky stripe through the eye
• A moderately forked tail fin
• A steeper body profile than the more elongated greater amberjack

The elongated, sickle-shaped dorsal fin lobes are the most reliable feature distinguishing this species from the greater amberjack and yellowtail, both of which have shorter, less pronounced fin lobes.

Almaco Jack are found in tropical and subtropical waters around the world, including the western Atlantic, Gulf of Mexico, Caribbean, eastern Pacific, and parts of the Indo-Pacific. They are strongly associated with offshore structure such as reefs, rocky ledges, seamounts, and shipwrecks, typically at depths ranging from near the surface to over 100 meters. Juveniles are often found near floating debris or sargassum in open water before shifting toward structure-oriented adult habitats. This species favors warm, clear marine waters and is not found in estuarine or brackish environments.

Almaco Jack are active predators that often gather around offshore reefs, wrecks, and other structure, feeding on smaller fish, squid, and crustaceans. They may form loose aggregations around productive structure, particularly where currents concentrate prey. Spawning occurs offshore during warmer months, with pelagic eggs and larvae drifting before juveniles settle near floating debris as a nursery habitat. As they grow, individuals move increasingly toward reef and wreck structure typical of adults. Almaco Jack serve as important mid-level predators on many reef systems, helping regulate populations of smaller reef-associated fish and invertebrates.