Family: Istiophoridae (Billfishes)
Genus and Species: Istiompax indica
Range: Black marlin are found almost entirely in the Indian and Pacific Oceans. In tropical areas distribution is scattered but continuous in open waters; denser in coastal areas and near islands. In temperate waters occurrence is rare. Black marlin have been known to migrate great distances. A black marlin was tagged and released at the Great Barrier Reef in Australia in September, 1972. It was recaptured 954 days later and approximately 2,000 miles away of the coast of New Zealand. Another was tagged off Cabo San Lucas, Mexico, and recovered off Norfolk Island in the South Pacific - more than 6,600 miles.
(click image to view anatomy)
Description: The black marlin is the only marlin, regardless of size, whose pectoral fins are rigid and cannot be folded flat up against the body without breaking the joints. The pectoral fins also have an airfoil shape, whereas those of other marlin are flat. The ventral fins are extremely short, almost never exceeding 12 inches in length. The first dorsal fin is retractable and fits into a groove along the back; it is proportionately the lowest of any billfish, usually less than 50 percent of the body depth. The leading edge of the second dorsal fin sits slightly in front of the second anal fin. The lateral line, which is rarely visible in adults, is a straight double row of pores.
Its body is laterally compressed, rather than rounded - much more so than in the similar-size blue marlin, and the upper jaw is elongated in the form of a spear. Dorsally, the body is a dark slate blue, but this coloring changes suddenly to a silvery white below the lateral line. Light-blue body stripes are usually visible on live marlin, especially when the fish is excited; these fade after death. Slight variations in color cause some specimens to have a silvery haze over the body. In Hawaii this has led to the name "silver marlin" (once thought to be a separate species). The name "white marlin," applied in Japan, refers to the color of the meat rather than the external color of the fish, and should not be confused with the white marlin species.
Natural History: Very strong and exceptionally fast, black marlin feed on squid and pelagic fishes including tuna and dolphin. Along with their cousins the striped marlin, they spawn in the Northern Pacific from May to August. Blacks exceeding 300 pounds are almost always females; a 500-pound male is a rarity.
Fishing Information: A highly rated game fish, the black marlin has the power, size, and persistence of which anglers dream. Black marlin tend to swim deeply, without jumping, when hooked, but can make spectacular jumps early in the battle. Fishing methods include trolling with large, whole baits or with artificial lures. Live bait is also effective.
Temperature Range: 68 - 86 degrees F.
Other Common Names: Pacific black marlin, giant black marlin, marlin negro, white marlin (Japan), silver marlin (Hawaii).
Largest recorded: 15 feet, 1,560 pounds (Cabo Blanco, Peru); 1,439 pounds (Cairns, Australia).
Sources: Marine Sportfish Identification, California Department of Fish and Game, 1987; FishBase, FishBase Consortium, 2014; Billfish, Saltaire Publishing, 1976; Phylogeny of Recent Billfishes (Xiphioidei), Collette, McDowell and Graves, 2006.
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