Broadbill Swordfish Xiphias gladius

The Broadbill Swordfish, Xiphias gladius, was named by Linnaeus in 1758. Xiphias gladius translates from Latin into “Gladiator of the sea”. The broadbill is the only species in the genus with no direct relatives. The color of the upper body is a dark blue with a bronze color mixed in. The lower body is a silvery white and the two colors blend to a brown. The bill is long and flat and constitutes 1/3 of the body. The dorsal fin is a rigid sickle and is equal shape and height as the upper caudal lobe and there are no pelvic fins. The adult fish have no teeth or scale and there is no visible lateral line. The weights are up to about 2,000 pounds.

 Xiphias has a history dating back to 450BC with the Greek writes Aristotle, Sophocles and others. Xiphias was considered to be a god at one time. After Achilles was killed, many of his followers jumped into the sea. The hero’s mother, who was a goddess, allowed them to keep their swords and turned them into fish: therefore, swordfish, king of the Mediterranean, the noblest warrior of all the sea.

The swordfish has a worldwide range in the tropical, subtropical and the temperate waters of the Pacific, Indian and Atlantic Oceans. During the warmer months, Xiphias prefers the cooler waters and during the cooler months Xiphias migrates to the tropical and subtropical domain. They do not stay in the tropical waters for very long except for spawning. Xiphias females may lay eggs every month of the year while the peak spawn is between June and July off the Charleston, South Carolina area and the Miami, Florida area in the Atlantic Ocean. Tens of millions of eggs are produce by Xiphias and fertilized externally. They lay eggs in water temperatures between 73^o to 75^oF. The eggs are around 5/64” (1.8mm) in diameter after fertilization. After a couple of weeks, the eggs turn into larvae. These larvae seem to have the largest mouth of all billfish larvae. The upper and lower jaws are the length and are full of teeth. The larvae feed on plankton, fish and crustaceans. They have also been known to swallow fish of their own size and to practice cannibalism. When Xiphias is about an inch long, it’s diet consist mainly of fish.

Their growth is slower than sailfish and other billfish. In the first year of their life they will grow to around 19” to 24”. The second year the length is between 32” to 36” and the third year will show length to 48”. The females will reach sexual maturity at 28” and males at 39”. The roe sacks will consist of two million to five million eggs.

Xiphias thrives in food enrich waters with surface water temperatures between 75^o to 85^o F. The large fish may be found in waters as low as 50^O, but smaller fish, under 250lbs, are rarely found in waters less than 64^o. Xiphias are roaming or pelagic fish found in water depths ranging from 600 feet to 2,000 feet.

Xiphias primarily feed on squid but may also feed on crustaceans and fish (there have been reports of finding sea birds found in their stomachs). They are ambush feeders and will swim up from the dark depths into a school of bait slashing it’s bill from side to side and then return to feed on the kill. The bill will also be used to feed on the bottom by getting hold of crustaceans, crabs and crayfish. Their diet also includes mackerel, bluefish, butterfish, bonita, small sharks, flounder and dolphin. Their favorite meal is squid and herring.

“I shall always be positive of the enormous size of this broadbill, and that, after being fought for half a day, and while still hooked, he began chasing flying fish.” Told by Zane Gray, Tales of Swordfish and Tune, Harper & Brothers, New York, 1927.

“Lassoing mountain lions, hunting grizzly bear, and stalking the fierce tropical jaguar, former pastimes of ours, are hardly comparable to the pursuit of Xiphias gladius. It takes more time, patience, study, skill, nerve and strength, not to mention money, of any game known to me… .” Wrote by Zane Grey, Tales of Swordfish and Tune, Harper & Brothers, New York, 1927.

Zane Grey also stated “the noblest warrior of all the sea fishes.”

Xiphias is known to be more aggressive and meaner than other billfish. Sharks have been impaled. Blue Whales and Fin Whales have had bills broken off in their bodies. In 1967, the submersible “Alvin” was rammed by a 198 pound broadbill and it became lodged in the outer hull.

These writing above tell of the strength and dominance of Xiphias. The mean-spirited billfish that is born with a nasty disposition has a soft mouth. This is a small problem in fighting the fish. Do you strike them hard and crank down on the drag to try and hit a bony area of the mouth or do you set the hook gingerly and fight them with a light drag? I use a hard set and a medium drag, about 15 pounds.

Xiphias can dive from the surface down a couple of thousand feet and back to the surface without any ill effects. The water temperature and be in the 70’s at the surface and in the 30’s in the depths. These temperature changes would be deadly to most fish, but Xiphias can maintain it’s body temperature with certain capillaries acting as heat exchangers keeping the brain and eyes heated. There is also a special organ in the head that keeps the eyes and brain heated at the cold depth while hunting for squid and fish.