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Swordfish

The swordfish (Xiphias gladius) are large, highly migratory, predatory fish characterized by a long, flat bill in contrast to the smooth, round bill of the marlins. Swordfish are elongate, round-bodied, and lack teeth and scales as adults. They reach a maximum size of 14 ft (4.3 m) and 1,190 lb (540 kg). The International Game Fish Association's all-tackle angling record is a 1,182 lb (536 kg) fish taken off Chile in 1953.

They are the sole member of their family Xiphiidae.

Swordfish are distributed throughout the world's marine ecosystem, in tropical, subtropical and temperate waters, between approximately 45° north and 45° south. They tend to concentrate where major ocean currents meet, and along temperature fronts. They inhabit the mixed surface waters where temperatures are greater than 15 °C but also can move and hunt in water as cool as 5 °C for short periods aided by specially adapted heat exchange organs which are able to increase the temperature of their brain and eyes by 10-15 °C.

Areas of greater apparent abundance occur north of Hawaii along the North Pacific transition zone, along the west coasts of the U.S. and Mexico and in the western Pacific, east of Japan. Migration patterns have not been described although tag release and recapture data indicate an eastward movement from the central Pacific, north of Hawaii, toward the U.S. West Coast. Acoustic tracking indicates some diel movement from deeper depths during the daytime and moving into the mixed surface water at night. At times they appear to follow the deep scattering layer, and small prey, as they undertake these vertical movements.
Females grow larger than males, as males over 300 lb (135 kg) are rare. Females mature at 4-5 years of age in northwest Pacific while males mature first at about 3 to 4 years. In the North Pacific, batch spawning occurs in water warmer than 24 °C from March to July and year round in the equatorial Pacific. Adult swordfish forage includes pelagic fish including small tuna, dorado, barracuda, flying fish, mackerel, as well as benthic species of hake and rockfish. Squid are important when available. Swordfish likely have few predators as adults although juveniles are vulnerable to predation by large pelagic fish.

While swordfish are cold-blooded animals, they have special organs next to their eyes to heat their eyes and also their brain. Temperatures of 10 to 15 C° above the surrounding water temperature have been measured. The heating of the eyes greatly improves the vision, and subsequently improves their ability to catch prey. Out of the 25 000+ species of bony fish, only about 22 are known to have the ability to heat selected body parts above the temperature of the surrounding water. These include the swordfish, marlin, tuna and some sharks.

Swordfish is a particularly popular fish for cooking, and the meat is usually sold as steaks, which are often grilled.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Swordfish".

Additional information:

Waters: Live in temperate waters worldwide

Description (in water): An enormous fish, weighing from 200 lbs. to as much as one ton. It was named for a long, swordlike projection from upper jaw. A tall, saillike dorsal fin propels this imposing fish through the waters of the world.

Description (in market): Meaty, dense mottled gray-white flesh that's firm in texture, moderate in fat content, and mildly flavorful.

Sold as: swordfish steaks or chunks, fresh or frozen

Best cooking: Firm and hearty, swordfish grills beautifully. Try a tangy marinade, or simply brush the fish with olive oil or soy sauce. All-purpose steaks can also be broiled, baked, or poached; chunks are delicious sautÚed, kebabed, or stir-fried.
Buying tips: Look for steaks that shimmer reflectively and are free of browning and signs of drying. The swirled meat should be tight, not "gaping" (separating), and should smell sweet.

Substitutes: Grouper, halibut, mahi-mahi, rockfish, red snapper, tuna

Notes: Swordfish is available fresh while it's in season from late spring and early autumn. You can find frozen steaks and chunks any time of the year.