CLASSIFICATION
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Xiphiidae
Genus: Xiphias
Species: Gladius
Binomial Name: Xiphias Gladius
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Xiphiidae
Genus: Xiphias
Species: Gladius
Binomial Name: Xiphias Gladius
MORPHOLOGY
The swordfish, as the only member of the family Xiphiidae, can be distinguished from other billfishes by the shape of its prolonged "bill", which appears as a flattened oval in cross section. The bill is long relative to other billfishes and adults lack teeth in the jaws. While the young have scales, these are lost by the time the fish attain a body length of about 3 feet . Adults lack scales and teeth. The body is generally cylindrical. Two dorsal fins are present, although the second is quite small, separated from the first, and set far back on the body. The first dorsal fin is high and rigid. Likewise, there are two anal fins, although again the second is considerably smaller than the first. Pelvic fins are absent. The caudal fin is lunate, while the caudal peduncle has a pronounced keel on either side. The lateral line is also present in specimens up to 3 feet in body length, but it too is lacking in adulthood. Prior to adulthood, swordfish morphology changes greatly, as described below. The color is blackish-brown above, fading to a lighter shade below. The fins are brown or dark brown.
BIOLOGY
Swordfish have evolved to be formidable predators. They possess acute eyesight, with which they can locate prey, and their flesh consists primarily of ‘white’ muscle which provides energy for sudden bursts of activity, such as when in pursuit of their quarry. The swordfish then uses its bill to stun or impale its victim, slashes it into pieces or swallows it whole. Swordfish feed during the day, primarily on squid, but also fish and occasionally crustaceans. They undertake vertical migrations in the ocean, following the movement of many small shrimp, fish and squid that move with the changing light intensity in a attempt to avoid predators. Unlike some fish, swordfish are unable to maintain a body temperature higher than the temperature of the surrounding water. Instead, they have a unique muscle and brown tissue that warms blood flowing to the brain and eyes, enabling it to tolerate the extreme cold of the ocean depths.
DISTRIBUTION MAP
IMPORTANCE
100 percent of the swordfish landed in Atlantic Canada is exported to the United States. In 2012 the export value was $10.6 million. In 2011, overall export value was $14.4 million. The 2011 landed value was $10.6 million . Swordfish are highly migratory pelagic fish and transboundary in their distribution throughout the Atlantic Ocean and the Mediterranean Sea. Swordfish migrate into the Canadian Exclusive Economic Zone during summer and fall to feed in the fertile waters of the continental slope and shelf basins areas.
FACTS
- One of the most confusing swordfish facts is how they actually use that extra long beak that travels out in front of them. Many people assume that they spear their prey with it when in all actuality, they slice away at their prey to make it a bit easier to catch. If they speared it, they would have no way to get it off to eat.
- The largest swordfish recorded being caught was in Chile in 1953, weighing 1,182 pounds.
- Males mature when they are between three to four years old while females take a year longer.
- One of the most fascinating swordfish facts is the way that they can select organs to heat. They are cold-blooded yet they can heat only their brain and eyes which significantly improves their vision. Out of 25,000 bony fish species, swordfish are one of the only 22 that have this ability.
- Swordfish are not social and do not swim in schools. They prefer to swim completely alone or not closer than 10 meters to another one of their kind.
- Swordfish generally eat every night. It is easier for them to rise to surface level in the dark to sneak up on smaller fish.
- Favorite foods of swordfish include squid, mackerel, menhaden, silver hake, bluefish, herring, butter fish, barracuda and tuna.
- Swordfish are generally not alarmed by large ships which makes them easy to harpoon. They are however, quite startled by small boats and have been known to put their swords right through the planking.
- Sperm whales, orcas and large sharks are the only real enemies to swordfish.
- A female can carry anywhere from 1 to 29 million eggs.
Symmetry
Swordfish like all vertebrates have bilateral symmetry. This means they have symmetry across one plane, which mean one side of their body approximately mirrors the other side.
RESCOURCES
http://w3.shorecrest.org/~Lisa_Peck/MarineBio/syllabus/ch8fish/Floridafishwp/kevin/classification.html
http://www.atlanticpanic.com/species/view/swordfish/
http://www.arkive.org/swordfish/xiphias-gladius/image-G27192.html
http://allamazingfacts.com/Amazing-Facts-about--Swordfish/577.php
http://www.dfo-mpo.gc.ca/fm-gp/sustainable-durable/fisheries-peches/swordfish-espadon-eng.htm
http://www.atlanticpanic.com/species/view/swordfish/
http://www.arkive.org/swordfish/xiphias-gladius/image-G27192.html
http://allamazingfacts.com/Amazing-Facts-about--Swordfish/577.php
http://www.dfo-mpo.gc.ca/fm-gp/sustainable-durable/fisheries-peches/swordfish-espadon-eng.htm