Swordfish
Xiphias gladius
Quick answer
The swordfish is a large, fast predatory fish named for its long, flat, sword-like bill, which it uses to slash at prey. It can grow about 3 m (10 ft) long and weigh over 450 kg (1,000 lb), and it lives in temperate and tropical oceans worldwide. A powerful migratory hunter, the swordfish feeds on fish and squid and can live around 9 to 15 years.
Swordfish facts at a glance
| Scientific name | Xiphias gladius |
|---|---|
| Diet | Carnivore (fish and squid) |
| Habitat | Temperate and tropical open oceans |
| Lifespan | 9–15 years |
| Length | Up to 3 m (10 ft), bill included |
| Top speed | Up to 80 km/h (50 mph) |
| Conservation status | Least Concern (IUCN) |
| Kingdom | Animalia |
|---|---|
| Phylum | Chordata |
| Class | Actinopterygii |
| Order | Istiophoriformes |
| Family | Xiphiidae |
| Genus | Xiphias |
Where it lives
Temperate and tropical oceans worldwide, hunting from the surface down to deep water.
Behavior and the sword
The swordfish's defining feature is its long, flattened upper jaw, which forms a smooth, sharp bill used to slash through schools of fish and stun prey. Unlike marlin, its bill is flat rather than round, and it lacks scales and teeth as an adult. Swordfish are mostly solitary and can warm their eyes and brain, sharpening their vision when diving into cold, deep water.
Diet and hunting
Swordfish are carnivores that feed on squid and a wide range of fish, from mackerel and herring to deepwater species. They often dive hundreds of meters during the day to hunt, then move toward the surface at night following their prey. The sword is used to injure or kill prey, which is then swallowed whole.
Habitat and range
Swordfish live in temperate and tropical oceans around the world, from the surface down to depths of several hundred meters. They migrate toward cooler, productive waters to feed in summer and warmer waters to spawn. They are highly mobile and can cross large stretches of open ocean.
Fishing and conservation
Swordfish are a popular commercial and sport fish caught with longlines and harpoons. Some populations were depleted in the past, but management measures have helped many recover, and the species is currently listed as Least Concern. Bycatch and the catch of juveniles remain concerns for sustainable fisheries.
Frequently asked questions about the Swordfish
Why do swordfish have a sword?
The long, flat bill is used to slash through schools of fish, stunning or injuring prey that the swordfish then eats. It may also help the fish cut through water more efficiently.
How fast can a swordfish swim?
Swordfish are among the fastest fish in the sea, with estimates of burst speeds up to about 80 km/h (50 mph) thanks to their streamlined, powerful bodies.
What do swordfish eat?
Swordfish are carnivores that feed mainly on squid and fish such as mackerel and herring, often diving deep during the day to hunt and rising toward the surface at night.
How big do swordfish get?
Swordfish can reach about 3 m (10 ft) in length, including the bill, and weigh over 450 kg (1,000 lb), with females generally growing larger than males.
Are swordfish dangerous to humans?
Swordfish do not target people, but there are rare cases of a hooked or harpooned fish injuring fishers with its bill. In normal conditions they pose little threat to humans.
How long do swordfish live?
Swordfish typically live around 9 to 15 years, with females often living longer and growing larger than males.
