Animalia Life

Makaira nigricans
FAMILY
Istiophoridae
TAXONOMY
Makaira nigricans Lacepede, 1802, Bay of Biscay. Some authors, such as Nakamura (1985), differentiate the Indo-Pacific blue marlin, M. mazara (Jordan and Snyder, 1901), as a separate species.
OTHER COMMON NAMES
French: Makaire bleu; Spanish: Aguja azul.
PHYSICAL CHARACTERISTICS
Blue marlin reach approximately 16 ft (5 m) in total length and weigh more than 1,984 lb (900 kg). Body not very compressed, nape highly elevated, body deepest at level of pectoral fins. Two dorsal and two anal fins. First dorsal fin with 39–43 rays; height of anterior lobe less than greatest body depth, not saillike. Second dorsal fin with six or seven rays, slightly posterior to second anal fin. Pectoral fins with 20–23 rays, depressible against sides of the body. Pelvic fins shorter than pectoral fins with one spine and two rays. Lateral line looped. Body covered with densely imbedded scales, each with one or two long, acute spines. Left and right branchiostegal membranes broadly united. Vertebrae, 24. Swim bladder made up of many small bubble-shaped chambers. Body blue dorsally, silvery white ventrally, first dorsal fin membrane blue-black, unspotted; body has approximately 15 obscure vertical light bars.
DISTRIBUTION
Most researchers consider the blue marlin to be a single pantropical species occurring in all three major oceans. Blue marlin are the most tropical of the billfishes, chiefly distributed in equatorial areas.
HABITAT
Epipelagic zone of oceans, usually waters with surface temperatures of 71.6–87.8°F (22–31°C).
BEHAVIOR
Observations suggest that marlins use their bills to stun their prey.
FEEDING ECOLOGY AND DIET
Feed mostly in near-surface waters but sometimes make trips to relatively deep waters for feeding. Prey includes dolphinfishes, tuna-like fishes, particularly frigate tunas, and squids.
REPRODUCTIVE BIOLOGY
Little is known about spawning grounds or seasons. The eggs are very small, approximately 0.04 in (1 mm) in diameter, and pelagic, hatching into planktonic larvae.
CONSERVATION STATUS
Not threatened.
SIGNIFICANCE TO HUMANS
Being excellent foodfishes, all species of marlin are of some importance to fisheries, particularly in Japan. They are mostly caught on long lines incidental to the target tuna species. FAO catch statistics for 1991–2000 show catches of 26.7–37.3 thousand tons (24.2–33.8 thousand metric tons) per year by 34 countries. Blue marlin are especially important to sportfishermen and are much sought after off Cuba and on the Bahamas side of the Straits of Florida. The alltackle gamefish record is a 1,402-lb (636-kg) fish taken off Vitуria, Brazil.

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