Little tunny

What it is

The little tunny is a compact, streamlined fish built for speed and endurance. Its body is torpedo-shaped with a metallic blue or blue-green back and a bright white belly. Distinctive wavy, worm-like markings appear above the lateral line, while dark, fingerprint-like spots decorate the area between the pectoral and pelvic fins. It lacks scales except along the lateral line and a thick corselet band. The first dorsal fin has tall spines, followed by a smaller second fin and several finlets. Adults typically reach 85 cm in length, though some grow up to 120 cm.

Where it lives

This species inhabits temperate and tropical neritic waters across the Atlantic Ocean, including the Mediterranean and Black Seas. In the western Atlantic, its range extends from Brazil to New England. It prefers warm water between 24 and 30 degrees Celsius. While primarily an offshore ocean dweller, it frequently enters inshore areas such as inlets and around jetties. It migrates north in spring and south in autumn, staying closer to shore than many other tuna species. Very young fish may enter estuaries in South Africa, though brackish water is generally avoided.

How it lives

Little tunny are carnivorous opportunists that feed in large schools. Their diet consists mainly of small schooling fish like sardines, anchovies, and hairtail, as well as crustaceans and squid. Food choices often depend on the size of the tunny and seasonal availability. They hunt near the surface where baitfish congregate. Predators include sharks, marlins, swordfish, seabirds, and larger tunas. The whale shark specifically targets their spawned eggs. Parasites such as sea lice and various worms also affect them. They maintain buoyancy through constant movement, lacking a swim bladder.

Breeding and life cycle

Spawning occurs in warm water above 25 degrees Celsius. In the Atlantic, this happens from April to November, while in the Mediterranean, it peaks between July and August. Females release millions of buoyant, transparent eggs in multiple clutches. Fertilisation takes place in the water column. Larvae hatch within 24 hours and develop adult features within weeks. Sexual maturity is reached at approximately three years of age, with females maturing at a smaller size than males. Major spawning grounds are located offshore in depths of 30 to 40 metres.

Fish and people

Anglers value the little tunny for its vigorous fight and high-speed runs when hooked. It is commonly caught by trolling lures near reefs or casting metal jigs. Despite its sporting appeal, it is often considered a rough fish for eating due to its coarse texture and strong, fishy taste. Consequently, many catch-and-release it or use it as bait for sharks and marlin. Commercial fisheries in the Mediterranean use longlines and nets, with catches peaking in warmer months. Historical records note significant migrations into the Adriatic, though these have declined.

Relatives and look-alikes

The little tunny is often confused with the Atlantic bonito, skipjack tuna, and bullet tuna. It can be distinguished from the bonito by its lower, sloping first dorsal fin and unique back markings. Unlike the skipjack, which has broad stripes on its belly, the little tunny displays dark spots between its fins. It is also related to the kawakawa and black skipjack, but differs by lacking teeth on the vomer bone in its mouth. These visual and anatomical differences help identify it among similar scombrid species.

Questions people ask about Little tunny

Good reading and sources

• Little tunny on WikipediaEncyclopedia
• More photos on Wikimedia CommonsPhotos
• Wikidata recordOpen data