The Black jack (Caranx crysos) is a brackish-water fish of the family Carangidae that grows up to 70 cm.
Description
The blue runner is a streamlined predator of the family Carangidae reaching about 70 cm. The back is light olive to blue-green, the flanks silvery-grey to golden; juveniles show about seven dark cross-bars. The species has two dorsal fins, sickle-shaped pectoral fins and a deeply forked tail. It lives in schools, usually not far from the coast, in the eastern and western Atlantic and the Mediterranean, to about 100 m. The blue runner hunts fish, shrimp and other invertebrates. It spawns offshore with pelagic eggs and is a valued food fish, though it can locally cause ciguatera poisoning when eaten.
Frequently asked questions
How do you recognise the Black jack?
The Black jack has a torpedo-shaped body, is mainly blue and shows a plain pattern.
Where does the Black jack live?
The Black jack lives in brackish water and is mostly found around stony or rocky ground.
How big does the Black jack get?
The Black jack grows to a maximum of about 70 cm. On average the species is around 40 cm.
Is the Black jack dangerous to humans?
The Black jack is venomous — handle spines with care and seek medical help after a sting if needed.
Is the Black jack edible?
Yes, the Black jack is commonly eaten.
Download Fin's Fish Guide
Identify fish in seconds, log your catches and dives. Join the TestFlight beta.
All data
Identification
Appearance
Habitat & distribution
Behaviour & biology
For anglers
Safety
Status & sources
Same genus Caranx
More from the family Carangidae
Download Fin's Fish Guide
Identify fish in seconds, log your catches and dives. Join the TestFlight beta.