Latin name

Xiphias gladius

Other names

Roadbill, broadbill swordfish; Arabic: kheil al bahar; French: espadon; Hawaiian: a’u ku; Italian: pesce sapda; Japanese: dakuda, medara, meka, mekaiiki; Norwegian: sverdfisk; Portuguese: agulha, espadarte; Spanish: aja para, aibacora, espada.

Identification

The swordfish has a strong, rather rounded body and large eyes. The first dorsal fin is tall, non-extending, and crescent-shaped. The second dorsal fin is widely separated from the first and small. Both fins are soft radial, with thin bony rods extending from the base of the fin and supporting the fin membrane. The anal fins are roughly the same shape as the dorsal fins, but noticeably smaller. The pelvic fins, located on the underside of the fish, are absent. There is a strong longitudinal keel, or ridge, on either side of the caudal fin that leads to a broad, sickle-shaped tail. Adult fish have no teeth or scales. The back may be dark brown, bronze, dark purple, grayish blue, or black. Flanks can be dark like back or dusky. The belly and undersides of the head are dirty white or light brown. The snout of the swordfish lengthens and takes the shape of a real sword. It is long, flat, pointed and very sharp (especially in small fish) and much longer and wider than in any other fish. The lower jaw is much smaller, but just as pointed, ending in a wide mouth. The body of swordfish fry differs significantly from that of adults. Their upper and lower jaws are equally elongated. Their body is long, thin, and snake-like, covered with coarse, spiny scales and plates, and has only one long dorsal and one anal fin.

Distribution

The Swordfish inhabits almost everywhere in temperate and tropical waters of the World Ocean, including the Mediterranean Sea and (rarely) the Black Sea and Sea of Azov. Occasionally, it even enters cold waters. They usually migrate from colder waters in summer to warmer waters in winter to spawn. In the Atlantic Ocean, swordfish inhabit from Canada to Argentina.

Habitat

Epipelagic and mesopelagic oceanic species. These are fish that live in the water column rather than on the bottom or in coastal areas. They usually live at depths of 600 to 2,000 feet and prefer waters with surface temperatures above 58 °F, although they can tolerate temperatures as low as 50 °F. There is some correlation between larger size and the ability to tolerate cooler temperatures. Few fish under 200 pounds are found in waters below 64 °F. In the western Atlantic Ocean, swordfish visit New England waters in summer and fall, entering warm Atlantic coastal waters from the far shelf in the Gulf Stream around June and leaving in late October. Such seasonal migrations between shore and sea are more common than those between the northern feeding areas off Cape Hatteras and the southern spawning grounds off Florida and the Caribbean.

Size

Swordfish are capable of growing to more than a thousand pounds, although fish of this size are not found these days. In the North Atlantic, fish over 400 pounds are highly unusual, and the average weight of fish caught in commercial fisheries is less than half that, with varying records ranging from 90 to 200 pounds. The world record caught on all tackle in 1953 weighed 1,182 pounds. The larger fish reach about 15 feet in length, have a body 10 feet long and a sword 5 feet long. Females grow faster, live longer, and are proportionately heavier than their males. Are large fish are always females. Males rarely weigh more than 200 pounds. The maximum lifespan of the fish is unknown, but they live at least 9 years. Most fish caught in the North Atlantic sport fishery are considered immature fish, less than 2 years old.

Life history and Behavior

Swordfish swim singly or in clusters up to 40 feet apart. They can often be found basking at the surface, spreading their first dorsal fins. Fishermen comment that it is a beautiful sight. Some researchers believe that the free hopping of these fish, also called "breaching," is an attempt to ward off pests such as remoras or lampreys. It may also be a way of surface feeding on small fish. They reach sexual maturity at about 2-3 years of age.

Food and feeding habits

A predator, it has a wide feeding spectrum because it feeds in a wide range of depths. Swordfish feed daily, most often at night. They may rise to the surface and into near-surface waters in the search for smaller fish or forage abundantly at depths of up to 1,200 feet. The most popular food is squid, but they also feed on menhaden, mackerel, bluefish, silver hake, butterfish, herring, and dolphin.

Reproduction

Spawning apparently at temperatures not lower than 24 °C. In the Atlantic Ocean, spawning takes place almost year-round in the Caribbean Sea, the Gulf of Mexico, and off the coast of Florida, with a peak in April through September. In the Pacific Ocean, spawning occurs in spring and summer (March to July) in its central part, in spring (September to December) - in the Southwest Pacific, and throughout the year - in equatorial waters. Spawning has been most extensively studied in the Mediterranean Sea, where the largest spawning aggregations are found.