Which fish is also known as a broadbill?

Sword, and Latin gladius: sword), also known as broadbill in some countries, are large, highly migratory, predatory fish characterized by a long, flat bill. They are a popular sport fish of the billfish category, though elusive. Swordfish are elongated, round-bodied, and lose all teeth and scales by adulthood.

These fish are found widely in tropical and temperate parts of the Atlantic, Pacific and Indian oceans, and can typically be found from near the surface to a depth of 550 m (1,800 ft). 2 They commonly reach 3 m (9.8 ft) in length, and the maximum reported is 4.55 m (14.9 ft) in length and 650 kg (1,400 lb) in weight. They are the sole member of their family Xiphiidae.

The swordfish is named after its bill resembling a sword (Latin gladius). 4 This makes it superficially similar to other billfish such as marlin, but upon examination their physiology is quite different and they are members of different families. They commonly reach 3 m (9.8 ft) in length, and the maximum reported is 4.55 m (14.9 ft) in length and 650 kg (1,400 lb) in weight.

34 The International Game Fish Association's all-tackle angling record for a swordfish was a 1,182 lb (536 kg) specimen taken off Chile in 1953. 2 Females are larger than males, and Pacific swordfish reach a greater size than northwest Atlantic and Mediterranean swordfish. 4 They reach maturity at 4–5 years of age and the maximum age is believed to be at least 9 years.

Swordfish are ectothermic animals; however, swordfish, along with some species of shark, have special organs next to their eyes to heat their eyes and brain. Temperatures of 10 to 15 °C above the surrounding water temperature have been measured. The heating of the eyes greatly improves their vision, and consequently improves their ability to catch prey.

78 Out of the 25,000+ fish species, only 22 are known to have a mechanism to produce heat. These include the swordfish, marlin, tuna and some sharks. Contrary to popular belief, the "sword" is not used to spear, but instead may be used to slash at its prey in order to injure the prey animal, to make for an easier catch.

4 Mainly the swordfish relies on its great speed and agility in the water to catch its prey. It is undoubtedly among the fastest fish, but the basis for the frequently quoted speed of 60 mph (97 km/h) is unreliable. Swordfish prefer water temperatures between 18 °C (64 °F) and 22 °C (72 °F),2 but have the widest tolerance among billfish and can be found from 5 °C (41 °F) to 27 °C (81 °F).

4 This highly migratory species typically moves towards colder regions to feed during the summer. 4 Swordfish feed daily, most often at night when they rise to surface and near-surface waters in search of smaller fish. During the day they commonly occur to depths of 550 m (1,800 ft) and have exceptionally been recorded as deep as 2,878 m (9,442 ft).

2 Adults feed on a wide range of pelagic fish such as mackerel, barracudinas, silver hake, rockfish, herring and lanternfishes, but they also take demersal fish, squid and crustaceans. 34 In the northwestern Atlantic, a survey based on the stomach content of 168 individuals found that 82% had eaten squid and 53% had eaten fish, including gadids, scombrids, butterfish, bluefish and sand lance. 10 Large prey-items are typically slashed with the sword, while small are swallowed whole.

Swordfish are not schooling fish. They swim alone or in very loose aggregations, separated by as much as 10 m (33 ft) from a neighboring swordfish. They are frequently found basking at the surface, airing their first dorsal fin.

Boaters report this to be a beautiful sight, as is the powerful jumping for which the species is known. This jumping, also called breaching, is thought by some researchers to be an effort to dislodge pests, such as remora or lampreys. Citation needed Almost 50 species of parasites have been documented in swordfish.

In addition to remoras, lampreys and cookiecutter shark, this includes a wide range of invertebrates such as tapeworms, roundworms and copepods. Except for humans, fully adult swordfish have few enemies. Among marine mammals, killer whales sometimes prey on adult swordfish.

4 The shortfin mako, an exceptionally fast species of shark, sometimes take on swordfish; dead or dying shortfin makos have been found with broken off swords in their head, revealing the potential danger of this type of prey. 11 Juvenile swordfish are far more vulnerable to predation and are eaten by a wide range of predatory fish. In the North Pacific, batch spawning mainly occurs in water warmer than 24 °C (75 °F) during the spring and summer, and year round in the equatorial Pacific.

2 In the north Atlantic spawning is known from the Sargasso Sea,3 and in water warmer than 23 °C (73 °F) and less than 75 m (246 ft) deep. 2 Spawning occurs from November to February in temperatures above 20 °C (68 °F) in the south Atlantic off south Brazil. 3 Spawning is year-round in the Caribbean Sea and other warm regions of the west Atlantic.