Swordfish: Habitat, Behavior, and Diet

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Swordfish (Xiphias gladius) was made famous in the late 1990's by Sebastian Junger's book The Perfect Storm, which was about a swordfishing boat lost at sea. The book was later made into a movie. Swordfishing captain and author Linda Greenlaw also popularized swordfishing in her book The Hungry Ocean.

Swordfish is a popular seafood that may be served as steaks and sashimi. Swordfish populations in U.S. waters are said to be rebounding after heavy management on a fishery that once overfished swordfish and also resulted in a large bycatch of sea turtles.

Swordfish Identification

These large fish, which are also known as the broadbill or broadbill swordfish, have a distinctive pointed, sword-like upper jaw that is over 2 feet long. This "sword," which has a flattened oval shape, is used to stab prey. Their genus Xiphias comes from the Greek word xiphos, which means "sword."

Swordfish have a brownish-black back and light underside. They have a tall first dorsal fin and distinctly forked tail. They can grow to a maximum length of over 14 feet and weight of 1,400 pounds. Females are larger than males. While young swordfish have spines and small teeth, adults do not have scales nor teeth. They are among the fastest fish in the ocean and are capable of speeds of 60 mph when leaping.


  • Kingdom: Animalia
  • Phylum: Chordata
  • Subphylum: Vertebrata
  • Superclass: Gnathostoma
  • Superclass: Pisces
  • Class: Actinopterygii
  • Order: Perciformes
  • Family: Xiphiidae
  • Genus: Xiphias
  • Species: gladius

Habitat and Distribution

Swordfish are found in tropical and temperate waters in the Atlantic, Pacific and Indian Oceans between the latitudes of 60°N to 45°S. These animals migrate to cooler waters in the summer, and to warmer waters in the winter.

Swordfish may be seen at the surface and in deeper waters. They can swim in deep, cold parts of the ocean due to specialized tissue in their head that warms their brain.


Swordfish feed primarily on small bony fish and cephalopods. They opportunistically feed throughout the water column, taking prey at the surface, in the middle of the water column and at the ocean bottom. They may use their sails to "herd" fish.

Swordfish appear to swallow smaller prey whole, while larger prey is slashed with the sword.


Reproduction occurs by spawning, with males and females releasing sperm and eggs into the water near the ocean surface. A female may release millions of eggs, which are then fertilized in the water by a male's sperm. The timing of spawning in swordfish depends upon where they live - it may either be year-round (in warmer waters) or during the summer (in cooler waters).

The young are about .16 inch long when they hatch, and their upper jaw becomes more noticeably longer when the larvae are about .5 inch long. The young don't begin to develop the sailfish's characteristic elongated jaw until they are about 1/4 inch long. The dorsal fin in young swordfish stretches the length of the fish's body and eventually develops into a large first dorsal fin and a second smaller dorsal fin. Swordfish are estimated to reach maturity at 5 years and have a lifespan of about 15 years.


Swordfish are caught by both commercial and recreational fishermen, and fisheries exist in the Atlantic, Pacific, and Indian Oceans. They are a popular game fish and seafood, although mothers, pregnant women, and young children may want to limit consumption due to the potential for a high methylmercury content.

Swordfish are listed as of "least concern" on the IUCN Red List, as many swordfish stocks (except for those in the Mediterranean Sea) are stable, rebuilding, and/or being adequately managed.


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  • Collette, B., Acero, A., Amorim, A.F., Bizsel, K., Boustany, A., Canales Ramirez, C., Cardenas, G., Carpenter, K.E., de Oliveira Leite Jr., N., Di Natale, A., Die, D., Fox, W., Fredou, F.L., Graves, J., Guzman-Mora, A., Viera Hazin, F.H., Hinton, M., Juan Jorda, M., Minte Vera, C., Miyabe, N., Montano Cruz, R., Masuti, E., Nelson, R., Oxenford, H., Restrepo, V., Salas, E., Schaefer, K., Schratwieser, J., Serra, R., Sun, C., Teixeira Lessa, R.P., Pires Ferreira Travassos, P.E., Uozumi, Y. & Yanez, E. 2011. Xiphias gladius. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.1. . Accessed July 31, 2012.
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  • Gloucester Times. The Perfect Storm: The History of the Andrea Gail. Accessed July 31, 2012.
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Kennedy, Jennifer. "Swordfish: Habitat, Behavior, and Diet." ThoughtCo, Apr. 5, 2023, thoughtco.com/swordfish-profile-2291589. Kennedy, Jennifer. (2023, April 5). Swordfish: Habitat, Behavior, and Diet. Retrieved from https://www.thoughtco.com/swordfish-profile-2291589 Kennedy, Jennifer. "Swordfish: Habitat, Behavior, and Diet." ThoughtCo. https://www.thoughtco.com/swordfish-profile-2291589 (accessed June 2, 2023).