Little tunny

The little tunny (Euthynnus alletteratus), also known as the little tuna, false albacore, or erroneously as the blue bonito, is a species of tuna in the family Scombridae. It lives in the Atlantic Ocean and the Mediterranean and Black seas; in the western Atlantic, it ranges from Brazil to the New England states. This fish is a pelagic fish often found far from shore and close to shore, and it moves a lot, making it a highly migratory species.

You can recognize the little tunny by the “worm-like” markings on its back and the dark spots between its pectoral and ventral fins. People often use this fish as bait for sharks and marlin because it has a lot of oil and holds onto hooks well. Many people think it tastes too strong and is hard to prepare, so it is usually not eaten and is called a rough fish.

But many people love to catch it for fun because it fights hard when hooked and can swim very fast—up to 64 km/h (40 mph). Anglers can catch it near reefs by using lures and fishing lines.

Taxonomy

Constantine Samuel Rafinesque identified the little tunny in 1810 and gave it its current name, Euthynnus alletteratus. Other names people have used for this fish include E. alleteratus alleteratus, E. alliteratus, E. thunina, and E. alletteratus aurolitoralis. Though it looks like many tuna, the little tunny is not part of the genus Thunnus but belongs to the tribe Thunnini.

Description

The little tunny is a smaller tuna with a streamlined body that helps it swim quickly and for long periods. It has a strong body shape like a torpedo, with a large mouth and special teeth on the roof of its mouth. It also has special fins, including a tall first dorsal fin and smaller second dorsal fin, along with other fins that help it stay balanced in the water.

This fish is usually a shiny blue or green color with dark, wavy lines on its back and white belly marked with unique dark spots near its fins. It can grow up to about 100 cm long and weigh around 12 kg, though most are smaller. It is often confused with other similar fish, but its special markings and lack of certain teeth help it stand out.

Anatomy

The little tunny differs from other tuna in a few ways. It does not have a swim bladder, so it must keep moving to stay afloat. Its liver is unusually shaped, and its stomach stretches almost the whole length of its body. The fish also has a special structure in its backbone that is important for its family.

Feeding habits

Little tunny are carnivorous fish that mainly eat small fish and invertebrates that travel in groups. They especially like to eat Atlantic bigeye and largehead hairtail. Besides fish, they also eat crustaceans, and sometimes small amounts of squid and other sea creatures. Their diet changes with their size—smaller little tunny eat small fish and tiny sea animals, while larger ones eat different types of fish. They share a similar diet to king mackerel because they are about the same size and live in the same parts of the water. Little tunny often eat near the surface, especially herring and sardines, and they usually feed together in large groups because their food also stays together in groups.

Distribution and habitat

The little tunny lives in the Atlantic Ocean, the Mediterranean Sea, and the Black Sea. You can find them from places like Skagerrak up to South Africa, but they are not often seen north of the Iberian Peninsula or south of Brazil. On the Atlantic coast of the United States, they can be caught as far north as Cape Cod, Massachusetts, and as far south as the tip of Florida, as well as in the Gulf of Mexico.

These fish like to stay close to shore, near places like inlets, points, jetties, and sandbars where small fish such as sardine and menhaden gather. They usually stay in warm water, between 24–30 °C (75–86 °F), and move south in the winter and fall, and north in the spring. They often swim together in large groups, sometimes with other types of fish from the same family.

Reproduction

Little tunny fish lay their eggs in warm water that is at least 25 °C (77 °F) from April to November in the Atlantic Ocean. In the Mediterranean, they mostly lay eggs between May and September, with the busiest time being July and August. These eggs are tiny, clear, and float in the water. After about a day, tiny baby fish called larvae are born. It takes about three years for little tunny to grow up and be able to have their own eggs.

Predators and parasites

The little tunny has many natural enemies. Larger fish such as marlins, sharks, rays, dolphin fish, wahoo, Atlantic sailfish, and swordfish often eat them. Even other tunas, including yellowfin tuna, will prey on little tunny. Seabirds also eat small little tunny.

Several types of small sea creatures live on the little tunny. Sea lice attach to its body and gills. Other parasites like flukes, gillworms, tapeworms, and isopods are also found on this fish.

Fishing

Like other fish you might see near the shore, such as bluefish and striped bass, you can often find schools of little tunny when birds are diving in the water. Fishermen catch them by trolling bait, using lures, or letting a line float in the water. When trolling, they use small lures with bits of fish or colorful feathers attached. When floating a line, they use small fish like Spot, Bluefish, or Pinfish as bait. Popular lures are bright, thin metal ones that look like the small fish the little tunny eat.

In the northern parts of the East Coast of the United States, people sometimes catch little tunny from the shore, especially in late summer when the water near beaches is clear. Some anglers use these fish to catch other species, but most are released because they are not usually eaten. There are not many rules about catching them, such as size or catch limits, or closed seasons.

The little tunny lives in the entire Mediterranean, especially around Sicily and the Ionian Sea. They love warm water and travel far during the spring and summer. Fishermen catch them using long lines, nets, and drift nets, with the most caught between April and September. Before overfishing, big groups of them used to swim up the Adriatic, where they could be seen from the land. The last big catch there was in 1954 near Trieste by fishermen from Santa Croce and Barcola.