Also called common jack, toro, cavally, cavalla, horse crevalle. The crevalle jack has a high, blunt head with a black spot on the back edge of the gill cover. The back is slate to bluish-black in color and the lower half is a bright silvery-yellow, with the anal fin being especially yellow. Crevalle jacks school by size, with the largest fish forming the smallest schools. When prey species are sighted, often near the surface, they make spectacular slashing attacks, with prey fish attempting to escape leaping in panic in every direction. After attack, they regroup for their next assault. Deep, compressed body. Blunt head with black spot on rear edge of gill cover. Hard scutes forward of sickle-shaped tail. Color usually yellowish with white undersides. The crevalle jack is the common jack of in shore oceanic waters. The species apparently can tolerate a wide range of salinities and occurs around off shore reefs, in coastal waters, harbors and protected bays, over highly saline shallow flats, in brackish waters at river mouths, and has even been known to travel up coastal rivers.
There is a rounded black spot at the lower base of the pectoral fin of the crevalle jack that is found in no other jacks in the area. There is also a distinct, vertically elongate black spot on the operculum. Enlarged scales or scutes, numbering about 30, extend in a line to the base of the tail fin. The similar horse-eye jack has no pectoral fin spot and 26-35 scutes.
A voracious predator, it feeds primarily on smaller fishes, which it often chases onto beaches or against seawalls. In open water, jacks will herd bait fish into a tight mass, then rush in from all sides. The crevalle jack also feeds on shrimp and other invertebrates and on garbage dumped from boats. This superb light tackle species can be taken by spinning, fly fishing, trolling, or surfcasting. Lures should be retrieved at a fast pace without pausing or stopping as jacks tend to lose interest in anything that doesn't act normally. Most jacks are not highly valued as food, though they are edible. Dorsal spines (total): 9; Dorsal soft rays (total): 19-22; Anal spines: 3; Anal soft rays: 15 - 18. Diagnosis: Scutes on lateral line 23 to 42. No scales on chest, except a small mid-ventral patch in front of pelvic fins. Upper profile of head steep. Maxilla ending approximately below or beyond posterior edge of eye (in adult). Front of soft dorsal and anal fins elevated; olivaceous to bluish green dorsally, silvery to brassy on the sides; prominent black spot posteriorly on gill cover at level of eye, another at upper axil of pectoral fins, and often a third on lower pectoral rays; caudal yellowish