Your client caught a juvenile blue runner, Caranx crysos, Charlie. Unlike adults, juveniles of this species have yellow median (dorsal, anal and caudal) fins and a series of broad, dark bands on their sides. Although faded, these bands can be seen on the fish in question. Additionally, unlike some other Atlantic members of the family Carangidae (the jacks), blue runners have a dark blotch by the upper posterior margin of each operculum, and this is apparent
on the fish in your photographs. Finally, the fish lacks adipose eyelids, which are characteristic of yellow jacks (C. bartholomaei) and bar jacks (C. ruber), similarly shaped species that also have yellow median fins as juveniles. Juvenile blue runners often form schools and are easily caught on sabiki or quill rigs or small jigs or shrimp-tipped hooks. They make excellent live bait for pelagic species including king mackerel (Scomberomorus cavalla) and sailfish (Istiophorus platypterus). Unfortunately, larger individuals are quite strong-tasting, which limits their appeal to many human would-be consumers. The maximum size achieved by blue runners is slightly more than 2 feet (the all-tackle record was an 11-pound, 2-ounce fish from the northern Gulf of Mexico in 1997), although the average size is considerably smaller. In the Western Atlantic, the blue runner ranges from Nova Scotia through Brazil, including Bermuda, the Bahamas, the Caribbean Sea and the Gulf of Mexico.