The blue marlin (Makaira nigricans) is one of the most highly sought after gamefish on the planet. They are prized catches for both commercial and recreational anglers. They can reach great size, and their meat is excellent as table fare.
With its spear-like bill, long body, giant tail fin and prominent dorsal fin, the blue marlin is fast and sleek, can leap high above the water’s surface, and change colors quickly when feeding or otherwise excited.
These large fish are most often blue-black on top with a white or silver underbelly. Its largest dorsal fin is usually dark blue or black with no dots or marks. Their sides have about 15 rows of cobalt-colored stripes which often fade quickly when caught. Their bodies are covered in thick, long scales. When swimming at their fastest speeds, their dorsal fins often fold flat against their bodies.
Blue marlin use their bills to slash at prey, injuring smaller fish then circling back to eat them. They eat any number of fish, including mahi, tuna, mackerel and squid.
Questions remain on whether blue marlin in the Atlantic Ocean are a separate species from blue marlin found in the Pacific Ocean. Most fisheries biologists think of them as the same species, however, others classify them as different.
Blue marlin travel extensively, with tagged fish caught up to 10,000 miles away. Tagged marlin have often been caught years after being tagged, within close proximity of their initial tagging spot. This leads scientists to believe blue marlins return to the same waters year after year.
1000+ pounders = “granders”
Female blue marlin grow up to four times the size of males. Males rarely reach 350 pounds. Females, however, can reportedly grow up to 1,800 pounds and 16 feet in length.
The largest concentrations of blue marlin at any time during the year are in waters right around 75 degrees. They travel the globe looking for waters in that temperature range.
They reach sexual maturity between 2 and 4 years of age, and spawn throughout the summer and fall. Females can release up to seven million eggs at once, and can spawn four times per year. Very few eggs result in fish that reach sexual maturity.
When young, blue marlin are highly susceptible to predation by every other fish in the ocean. Once grown, they have few predators, with killer whales, pelagic sharks and man being their only threats.
Blue marlin are closely related to striped marlin, black marlin and white marlin, and are sometimes misidentified as those species. Nicknames include Man in the Blue Suit, blue one, line burner, ocean gar and sulisuli. Those reaching 1,000+ pounds are known as “granders.”
The Louisiana state record blue marlin weighed 1,018 pounds and was caught by Linda Koerner in July 1977.
The world record stands at 1,402 pounds and was caught by Paulo Amorim out of Vitoria, Brazil in February 1992.