Swordfish Xiphias Gladius
Swordfish Xiphias Gladius

Swordfish Xiphias Gladius


The Swordfish’s scientific name Xiphias Gladius derives from the Greek word for sword Xiphos and Latin word for sword Gladius! Usually large, migratory predators these well known fish are found widely in tropical and temperate waters. The average weight of these fish in the Mediterranean is the smallest of all other areas where these fish are encountered around 120-160kg! The maximum size recorded (Pacific Ocean) is a length of 4.5m and weighing in at 540kg!


Swordfish are epipelagic and mesopelagic fish. Usually found in waters warmer than 12-13°C. They can tolerate the greatest temperature variation out of all bill bearing fish with a recorded temperature tolerance range from 5°C to 27°C. Found usually near the surface but known to dive to an excess of 550m! They are found the world over in the Pacific Ocean, Atlantic Ocean, Mediterranean Sea, Indian Ocean, Caribbean Sea, Marmara Sea, Black Sea, Sea of Azov and Gulf of Mexico!  They feed close to the surface during the night mostly! They have few natural predators namely large sharks, sperm and killer whales.


In deep waters they feed mainly on tuna, dolphinfish, flyfish, barracuda, while in relatively shallower waters they feed on mackerel, herring, sardines, sauries, needlefish and others. While considered surface dwelling adult swordfish will make their way to the bottom to feed on hakes, bramidae, redfish, lanternfish and others. Based on stomach content analysis the swordfish uses its sword to kill some of its prey namely squid and cuttlefish found to be slashed inside their stomachs!

Life History

They are not schooling fish!They swim alone or in small schools swimming far apart from each other. In the Mediterranean spawning usually peaks in June and July. During this time concentrations of swordfish spike, while during the rest of the year the distribution is more spread out! Larger females carry more eggs than smaller ones and ranger from 1 – 29 million eggs per fish! They are usually 1.5mm – 2mm in diameter and around 3 days after fertilization the embryonic stage begins. The surface living unique larvae are usually 4mm long just before hatching! Their sword bill is evident when the larvae reach 10mm long.

Xiphias Gladius Mediterranean Sea Distribution Map
Xiphias Gladius Mediterranean Sea Distribution Map
(Chance of Encounter Red=0.8 Yellow=0.2)


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