WHAT IS A SWORDFISH?
These large marine predators are fearsome solitary hunters with a lifespan of about 10 years. Also known as broadbills due their broadsword of a nose, they ironically lose all their teeth by adulthood. Swordfish normally grow up to 10 feet (3 meters) in length (though the females are larger then the males). And with their large size, their deadly nose has a broad reach with which to slash and injure prey. Often seen by boat captains breaching (leaping out of the water) they are a beautiful sight. Fisherman beware though. Swordfish are one of the fastest fish alive, capable of hitting speeds up to 50 m.p.h. (80 k.p.h.). And when its this nocturnal predator’s time to die, they’re not above taking you with them. In general swordfish like to dine on hake and bluefish among others.
WHERE DO SWORDFISH COME FROM?
The Indian, Atlantic and Pacific oceans are home to this fish. They prefer to swim at mid-water depths of around 1,000 feet (304 meters). These fish are also more temperature resistant then most of their family, living in water ranging from 40 F to 80 F degree (4 C to 27 C).
WHEN IS A SWORDFISH IN SEASON?
While they are available year-round, in North America they’re harvested mostly from April to December. Migratory creatures, they travel to northern, cooler waters in warmer weather, and head down south to warmer temperatures in colder weather.
DO SWORDFISH HAVE EYEBALL HEATERS THAT KEEP THEIR BRAINS FROM FREEZING?
Like sharks, swordfish are ectothermic or cold blooded organisms. However they are unique in that they have organs that generate heat next to their eyeballs. With eyes the size of tennis balls and a brain to boot, it takes a lot of energy to keep these two organs warm in a cold water environment. It turns out that heating their eyeballs allows swordfish to more effectively capture light. This is crucial when hunting fast moving prey in low-light nocturnal conditions. At lower depths the water is much colder and less light is available. This also means that there’s less predatory competition for available sources of food.
ARE SWORDFISH HEALTHY TO EAT?
Swordfish are one of the dirty dozen (mercury). The higher up in the food chain a predator is, the more heavy metal toxins they absorb from their surrounding environment. So avoid eating this fish on a regular basis. To be fair, there is a lot of debate on this topic. Some experts recommend avoiding this fish entirely. Others say the other health benefits this predator offers combined with a more varied diet in general outweigh the negatives.