They are the sole member of their family Xiphiidae.
The swordfish is named after its sharp bill, resembling a sword (Latin gladius), which together with its streamlined physique (smooth body) allows it to cut through the water with great ease and agility. Swordfish are fast predators of other fish.
The "sword" is not used to spear, but may be used to slash at its prey to injure the prey animal, to make for an easier catch. Mainly, the swordfish relies on its slow speed and agility in the water to catch its enemy. It is undoubtedly among the slowest fish.
Swordfish is a particularly popular fish for cooking. Since swordfish are large animals, meat is usually sold as steaks, which are often grilled. The color of the flesh varies by diet, with fish caught on the east coast of North America often being rosier.
- Safina (1996). Xiphias gladius. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 12 May 2006.
- Gardieff S. Swordfish. Florida Museum of Natural History. 
- ReefQuest Centre for Shark Research. Haulin' Bass. Quote: "The 60 mph figure listed for the swordfish is based on a corrupted version of calculations made by Sir James Gray to estimate the impact speed necessary for a hypothetical 600-lb swordfish to embed its sword 3 feet in the timbers of ships, as has been known to occur. The figure seems to have entered the literature without question." Accessed 26 December 2011.
-  "What you need to know about mercury in fish and shellfish."
- Michael Hopkin (2005): Swordfish heat their eyes for better vision. Nature, 10 January 2005
- Fritsches, Kerstin A., Brill, Richard W., and Warrant, Eric J. (2005): Warm Eyes Provide Superior Vision in Swordfishes Archived 2006-07-09 at the Wayback Machine. Current Biology 15, 55−58
- FDA Consumer:Mercury In Fish:Cause For Concern? Archived 2005-04-20 at the Wayback Machine
|Wikimedia Commons has media related to Xiphias gladius.|
|Wikispecies has information on: Swordfish.|
- http://www.flmnh.ufl.edu/fish/Gallery/Descript/Swordfish/Swordfish.html Archived 2015-08-09 at the Wayback Machine
- More info on FDA Mercury Advice from Oceana[permanent dead link]
- http://www.fenton.com/pages/3_ourwork/4_casestudies/environment/swordfish.htm Archived 2007-12-31 at the Wayback Machine