Blue Marlin

The biggest females are more than four times as heavy as the biggest males, which rarely exceed 160 kg (350 lb) in weight. The longest females can reach a length of 5 m (16 ft) with the bill, from eye to tip, constituting about 20% of the total body length.

Body mass in the largest female specimens has been reported from 540 to 820 kg (1,190 to 1,810 lb), depending on the source (few large specimens are scientifically verified). The largest blue marlin caught by IGFA angling rules is from Vitoria, Brazil, which weighed 1,402 lb (636 kg).; fishermen often refer to individual marlins that reach or exceed 1,000 pounds as "granders".

Both sexes have 24 vertebrae, of which 11 are precaudal and 13 are caudal.

Blue marlin are found year-round in tropical oceanic waters of the Atlantic. The range expands into temperate waters of the Northern and Southern Hemispheres during the warmer months and contracts towards the Equator during colder months. Warm currents, such as the Gulf Stream, in the western Atlantic have a major influence on their seasonal distribution.

Being the most tropic of all the billfishes, they spend a lot of time in the water column shifting from the top to a depth of 100 meters. They spend most nights near the surface and dive to deeper depths during the day. Limited from going any lower by the water temperature and oxygen levels.

Once blue marlin reach maturity, they have few predators, with the most important being killer whales and large pelagic sharks, such as the shortfin mako and great white shark.

Blue marlin have many parasites, including from these groups: Digenea (flukes), Didymozoidea (tissue flukes), Monogenea (gillworms), Cestoda (tapeworms), Nematoda (roundworms), Acanthocephala (spiny-headed worms), copepods, barnacles, and cookiecutter sharks.

Sport fishermen first encountered blue marlin in the Bahamas in the 1920s and early 1930s, when pioneering big-game fishermen such as Van Campen Heilner and S. Kip Farrington began exploring the waters offshore of Bimini and Cat Cay. Since then, blue marlin have been renowned as one of the world's greatest game fishes. The sportfishing pursuit of marlin and other billfish has developed into a multimillion dollar industry that includes hundreds of companies and thousands of jobs for boat operators, boat builders, marinas, dealerships, and fishing tackle manufacturers and dealers.