Sarda Sarda

– Atlantic Bonito –

The Atlantic bonito (Sarda sarda) is a large mackerel-like fish of the family Scombridae. It is common in shallow waters of the Atlantic Ocean, the Mediterranean Sea, and the Black Sea, where it is an important commercial and game fish.

Description

Atlantic bonito belong to a group which have the dorsal fins very near, or separated by a narrow interspace. Its body is completely scaled, with those scales in the pectoral fin area and the lateral line usually larger in size. Bonitos (fishes in the genus Sarda) differ from tuna by their compressed bodies, their lack of teeth on the roof of the mouth, and certain differences in colouration.

Atlantic bonito share Atlantic waters with the striped bonito, Sarda orientalis (the Atlantic population of which is sometimes considered a separate species, Sarda velox). The striped bonito has been taken on the Atlantic coast as far north as Cape Cod. It is similar in its habits, but somewhat smaller than the more common Atlantic bonito. The Atlantic bonito can be distinguished from its relative by its dark oblique stripes on the back and with a maxillary only about half as long as the head, whereas the striped bonito has striping on its topside nearly horizontal and a maxillary more than half the length of the head.

Atlantic bonito grow up to 75 centimetres (30 in) and weigh 5–6 kilograms (11–13 lb) at this size. The world record, 18 pounds 4 ounces (8.3 kg), was caught in the Azores.^[4]

The striped-backed bonito has a spindle-shaped body, compressed laterally. The livery is pearly. The back, dark and bluish, is decorated with 5 to 11 longitudinal and oblique dorsal bands, more or less marked, which start from the top of the back to the flanks. The belly, clearer, is uniform. The two dorsal fins are weakly separated ; the first has a straight edge. The head, elongated, is armed with a powerful jaw, widely split; she wears relatively small eyes. The caudal peduncle * has a carina * and pinnules *: 7 to 9 on the dorsal part and 6 to 8 on the anal part . The caudal, forked, is homocerque *.

Biotope

The striped-backed skipjack is a neritic * oceanic species found in tropical and temperate zones. It performs seasonal migrations, approaches the coast during the summer period and sometimes enters brackish water *.
It is found in shoals, rather near the surface, above the continental shelf.

Similar Species

Confusions are possible with other species of the Scombridae family.

• Striped bonito Katsuwonus pelamis (Linnaeus, 1758): as its name suggests, the longitudinal bands are arranged only on the ventral part.
• Common tuna Euthynnus alletteratus (Rafinesque, 1810) shows mottling on the back, but also black spots between the pectoral fins and pelvic fins.

It can also be confused with young tunas but the latter have a dark and uniform dorsal livery.

Habits

It is a strong swimmer. Normally, it travels in fairly large schools and is common offshore in the vicinity of New York City, where it is known as “skipjack” because of its habit of jumping from the water. (However, the name “skipjack” more commonly refers to the skipjack tuna, Katsuwonus pelamis.) The spawning season is June, and specimens 12–15 centimetres (4.7–5.9 in) long are taken in September off Long Island.

Alimentation

The striped-backed skipjack, a diurnal predator, feeds mainly on small pelagic fish * (anchovies, sardines, etc.), but it also feeds on small pelagic invertebrates such as shrimps and cephalopods. Its large and powerful jaw allows it to capture large prey. It is preferentially ichthyophagous *. There is also cannibalism in this species.

Atlantic bonito eat mackerel, menhaden, alewives, silversides, sand lances, and other fishes, as well as squid.

Reproduction

The spawning period takes place in spring and summer, more or less early in the season depending on the latitude. The spawning takes place earlier in the southern waters of the Mediterranean.
The first sexual maturity is reached at a size between 37 and 40 cm. The sexes are separate. A female produces between 400,000 and 500,000 eggs per year.
The eggs and larvae * are pelagic.

Various Biology

Sarda sarda is eurythermal *, it supports temperatures between 12 ° C and 27 ° C and euryhaline * with an amplitude of 14 to 39 ‰. It therefore adapts to variations in environmental conditions, provided that these variations are not sudden.
It is a gregarious species *, living in schools, more or less dense, of a few individuals to several hundred.
Its maximum longevity would be of the order of 5 years.
Its scales are small and cycloid-like *.

Further Information

Ancient naturalists made many confusions between the different species of bonito and tuna, adults and juveniles, until the 19th century. This explains the large number of synonymous scientific names.
The striped-backed skipjack is a species of high commercial interest. This fish is eaten fresh, dried, salted, smoked, canned or frozen.
In the inter-tropical zone, this species can transmit ciguatera *.

Fishing Technique

Bonito are often captured by tuna fishermen when trolling for bigger game. Bonito have also been caught using pound nets, and amongst other species as bycatch during the traditional fishing practice of Almadraba in addition to the main catch, the far larger Atlantic bluefin tuna. Thought by most fishermen to be inferior to tuna as a food fish, possibly because of the greater oiliness, it is sometimes used as bait.

As Food

Bonito is a popular food fish in the Mediterranean; its flesh is similar to tuna and mackerel, and its size is intermediate between the two.^[5]

Bonito under 1 kg (2.2 lb) or so (called palamut ~ паламуд in Bulgarian) are often grilled as steaks. Larger bonito (torik in Turkish) are cut into steaks and preserved as lakerda.^[5] Bonito is also canned, but canned bonito del norte (Spanish) is not bonito, but albacore tuna.

In Algeria and Spain, it is often prepared as escabeche, which preserves it for about a week.^[5] Bonito may also be baked and served cold.^[6]