Skipjack Tuna Identification Guide
Identify skipjack tuna by its belly stripes, distinct from the back markings of bonito and little tunny.
Read the full Skipjack Tuna encyclopedia entry →
Key identification features
- Robust, fusiform, scaleless body except for a corselet of larger scales around the head and pectoral region
- Back is dark purplish-blue with no markings
- The diagnostic feature is 4 to 6 dark, straight longitudinal stripes running along the lower sides and belly, not the back
- No swim bladder, and a slender caudal peduncle with a strong central keel
- Deeply forked, crescent-shaped tail
Common look-alikes
- Little tunny: has dark, wavy or wormlike markings on the upper back above the lateral line and scattered dark spots between the pectoral and pelvic fins, rather than straight belly stripes
- Atlantic bonito: shows diagonal dark stripes running down from the back, the opposite pattern from skipjack's belly stripes
- Bullet tuna: smaller, with a shorter body, larger eye relative to head size, and less pronounced belly striping
Where you'll see one
Skipjack tuna occur throughout tropical and warm-temperate oceans worldwide, traveling in large surface-oriented schools well offshore, often associated with current lines, floating debris, upwellings, or feeding birds working baitfish near the surface.
Frequently asked questions
How do I tell skipjack tuna from little tunny (false albacore)?
Skipjack has straight dark stripes along the belly and lower sides, while little tunny shows wavy, wormlike markings on the upper back instead.
What separates skipjack tuna from Atlantic bonito?
The stripe placement is reversed - skipjack's stripes run along the belly, while bonito's diagonal stripes run down from the back.