The Blue marlin is the largest billfish. Blue marlin, or Kajiki in Japanese, is distinguished by its large size, heavy bill and rougher, darker skin compared to its more slender cousin the striped marlin. Marlins are a highly migratory fish living at the top of the food chain in the tropical and subtropical regions of the world’s oceans. The blue marlin is found in the Pacific, Indian and Atlantic. It is a member of a larger family known as billfish, which get their name from their upper jaw that extends to form a spear. Because of its immense size, weighing up to 1,600 pounds, marlin is prized as a sports fish. The upper jaw forms a large bill. The body is cylindrical from anal fin forward. Two dorsal fins are present; the first dorsal fin is high and slopes steeply posteriorly, while the second is small. The caudal peduncle has keels. The lateral line forms a large net-like pattern of hexagons canvasing the sides of the fish. The pelvic fins are slender. The lateral keels on the caudal peduncle assist in making this fish a powerful swimmer of great speed and stamina. Grooves for the pelvic fins improve hydrodynamics. Dorsal spines (total): 0; Dorsal soft rays (total): 45-50; Anal spines: 0; Anal soft rays: 19 - 23. Body blue-black above and silvery white below, with about 15 rows of pale cobalt-colored stripes; 1st dorsal fin plain blackish or dark blue, other fins brown black with a tinge of dark blue in some specimens; anal fin bases with a tinge of silvery white. Lateral line a network of interconnecting canals