The striped marlin (Family Istiophoridae) is a large, oceanic fish with a long, round bill, small teeth and tall dorsal fin which decreases in height ending just before the second dorsal fin. Striped marlin reach a maximum size of nearly 12 feet, weighing over 450 pounds. The International Gamefish Association all-tackle record is for a 494-pound fish caught near New Zealand in 1986. The species is widely distributed throughout most tropical and sub-tropical waters of the Pacific and Indian oceans. Fishery data indicate a horseshoe-shaped distribution across the central north- and central south Pacific with a continuous distribution along the west coast of the Central Americas. It is apparently more abundant in eastern and north central Pacific than elsewhere.
Movements tend to be diffusive as striped marlin do not to form dense schools but occur singularly or in small groups, usually segregated by size. Adult fish are found in the north- and south- central Pacific where spawning occurs. Spawning occurs in the central Pacific and off central Mexico. Sub-adult fish move east toward the coast of Mexico where they are found in high abundance around the tip of the Baja peninsula. Most striped marlin caught in the southern California sport fishery are three to six years old and weigh 120 to 200 pounds. Striped marlin are not reproductively active while off southern California.
Tag recapture data indicate movement from southern California to Baja California Sur, Mexico but show little or no movement in the reverse direction. Tag recapture data further reveal movement from off Mexico and southern California to near Hawaii, Peru, and the south Pacific near the Marquises Islands. Striped marlin are epipelagic, preferring water temperatures of 20° to 25°C during all stages of their life cycle. Acoustic telemetry studies indicate they spend 86% of their time in the surface layer above the thermocline.
Striped marlin are opportunistic feeders on epipelagic fishes including mackerel, sardine, anchovy, and will take invertebrates including squid and red crab when available. Off southern California, they are often seen feeding at the surface on these small coastal fish. Predation on adult marlin has not been documented but may occur from large pelagic sharks or toothed whales.