Body silvery, but can darken to almost black, especially when feeding near the bottom. A bright blue-and-black border runs along the dorsal fin and onto the lower tail fin (C. ruber).
Size up to 59 cm.
Common in clear insular areas or in reefs, common to 35 m. Juveniles frequently in areas with algae. Usually in schools which may be spawning groups, occasionally solitary. Feeds on fish, shrimps and other invertebrates.
Common Florida, Bahamas and Caribbean.
The related Blue runner (Caranx crysos) lacks the bright blue border along the fins, but has dark tips of the tail fins.