The Atlantic blue marlin (Makaira nigricans) is a species of marlin endemic to the Atlantic Ocean. Marlin is a popular game fish. Blue marlin are distributed throughout the tropical and subtropical waters of the Atlantic, Indian and Pacific Oceans. A blue water fish that spends the majority of its life in the open sea far from land. Females can grow up to four times the weight of males. The maximum published weight is 818 kg (1,803 lb) and length 5 m (16.4 ft). The biggest females are more than four times as heavy as the biggest males, which rarely exceed 160 kilograms (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 lbs). Blue marlin, like other billfish can rapidly change color, an effect created by pigment-containing iridophores and light-reflecting skin cells. Most often, however, the body is blue-black on top with a silvery white underside. It has about fifteen rows of pale, cobalt-colored stripes, each of which has round dots and/or thin bars, located on both sides of the fish. Blue marlin are found year-round in tropical oceanic waters of the Atlantic and Indo-Pacific. 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 and the Agulhas Current in the western Indian Ocean have a major influence on their seasonal distribution.