Striped Marlin

The only known predators of this species are great white sharks, killer whales, and humans.

Known Predators:

• Great white shark (Carcharodon carcharias)
• Killer whale (Orcinus orca)
• Humans (Homo sapiens)

Anti-predator Adaptations: cryptic

Striped marlin may communicate visually with conspecifics via use of their chromatophores. Such communication may be used to signal spawning readiness. Like other teleost fishes, striped marlin have olfactory nares to detect chemicals in the water, helping them find mates or prey. They also have large eyes which enable them to hunt at night or at depths with low levels of light. The lateral line, running along the sides of the fish, senses pressure differences and heightens its awareness of its surroundings.

Communication Channels: visual ; chemical

Perception Channels: visual ; tactile ; acoustic ; vibrations ; chemical

It is estimated that populations of striped marlin have declined by 20-25% since the mid 1990s. More detailed and frequent stock assessments in the Indian Ocean as well as the northwest Pacific Ocean need to be conducted to obtain basic biological information on this species for its effective management.

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

After spawning has occurred, fertilized eggs develop into planktonic, lecithotropic larvae that drift for several weeks to months before the larvae develop into small fry. Little is known specifically about the early life stages of this species.

Development - Life Cycle: indeterminate growth

There are no known adverse effects of striped marlin on humans, though eating striped marlin and other large predatory fishes may put people at risk of illness due to high levels of mercury retained within the fish's muscle tissue.

Striped marlin fight when caught by hook and line, providing sport fishermen with recreational opportunities. Catch and release of this species is recommended in waters of the United States. While this species is not usually consumed in the United States, it is considered a delicacy in Asia.

Positive Impacts: food ; ecotourism

Striped marlin have an important role in the epipelagic marine food chain as apex predators, helping to regulate the population of cephalopods and fish. Furthermore, this species hosts a number of parasites, including copepods and a variety of flatworm species.

Commensal/Parasitic Species:

• Gloiopotes huttoni (Subclass Copepoda, Subphylum Crustacea)
• Pennella filosa (Subclass Copepoda, Subphylum Crustacea)
• Capsala ovalis (Class Monogenea, Phylum Platyhelminthes)
• Capsaloides hofmannae (Class Monogenea, Phylum Platyhelminthes)
• Capsaloides istiophori (Class Monogenea, Phylum Platyhelminthes)
• Capsaloides sinuatus (Class Monogenea, Phylum Platyhelminthes)
• Tristomella laevis (Class Monogenea, Phylum Platyhelminthes)
• Tristomella pricei (Class Monogenea, Phylum Platyhelminthes)

Planktonic larvae and small juveniles consume zooplankton. Dietary analysis of adult striped marlin during a yearly cycle in the southern Gulf of California, Mexico, found prey consisting of epipelagic organisms from the neritic and oceanic zones. The most abundant prey noted were chub mackerel (Scomber japonicas), California pilchard (Sardinops sagax) and jumbo squid (Dosidicus gigas).

Animal Foods: fish; mollusks; other marine invertebrates; zooplankton

Primary Diet: carnivore (Piscivore , Molluscivore ); planktivore

Striped marlin are pelagic billfish native to the Indian and Pacific oceans. They are found in coastal waters offshore of Africa, Mexico, South America, and New Zealand. In North American waters, Striped marlin are most common south of Point Conception, California, but range as far north as Oregon.

Biogeographic Regions: indian ocean (Native ); pacific ocean (Native )

Striped marlin inhabit pelagic waters and their population density is positively correlated with distance from shore. These fish are generally found in the epipelagic zone.

Range depth: 0 to 200 m.

Habitat Regions: temperate ; tropical ; saltwater or marine

Aquatic Biomes: pelagic ; coastal

Striped marlin live from 8 to 10 years. They are not maintained in captivity.

Range lifespan
Status: wild: 8 to 10 years.

Typical lifespan
Status: wild: 8 to 10 years.

Striped marlin are bony fish that are similar in appearance to sailfish, with a distinguishable difference in the dorsal fin (in Striped marlin the dorsal fin is much smaller and tapers toward the caudle peduncle). With a fusiform-shaped body, striped marlin glide through the water with little resistance. Striped marlin have the thinnest bill amongst all billfishes and slash their prey as opposed to impaling them as other members of the family do. Striped marlin have a distinct color patterning of 10-20 blue bars extending from the head and continuing to the caudal fin. When the fish is excited, the coloration of these bars rapidly changes from blue to lavender via the contraction or expansion of chromatophores (special pigmented cells in the integument).

Range mass: 224 (high) kg.

Range length: 3.35 (high) m.

Other Physical Features: endothermic ; bilateral symmetry

Sexual Dimorphism: female larger

Striped marlin form groups and/or schools during their reproductive season. As a broadcast spawning species, males and females potentially have multiple mates. Further information regarding courtship behavior is currently unavailable.

Mating System: polygynandrous (promiscuous)

Female striped marlin reach sexual maturity at 1.5-2.5 years of age while males reach sexual maturity at 1-2 years of age. Striped marlin reproduce by broadcast spawning (the female releases eggs which are fertilized in the water column). Females may produce 11-29 million eggs annually.

Breeding interval: Striped marlin spawn annually.

Breeding season: Striped marlin spawn during the months of November and December

Range number of offspring: 11 million to 29 million.

Range age at sexual or reproductive maturity (female): 1.5 to 2.5 years.

Range age at sexual or reproductive maturity (male): 1 to 2 years.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); broadcast (group) spawning; oviparous

Gametes are shed into the water during spawning; there is no further parental care.

Parental Investment: no parental involvement

fieldmarks: Anterior lobe of first dorsal fin pointed and higher than remainder of the fin, the height decreasing gradually backward; anus situated near origin of first anal fin, the distance between them smaller than half of anal fin height; tips of pectoral and first anal fins pointed. Body elongate and fairly compressed. Bill stout and long, round in cross section; nape fairly elevated; right and left branchiostegal membranes completely united to each other, but free from isthmus; no gillrakers; both jaws and palatines (roof of mouth) with small, file-like teeth. Two dorsal fins, the first with 37 to 42 rays, usually with a pointed anterior lobe, higher than (or occasionally equal to) body depth anteriorly, the fin then abruptly decreasing in height to about the 10th dorsal fin ray and gently decreasing further backward; first dorsal fin base long, extending from above posterior margin of preopercle to just in front of second dorsal fin origin; second dorsal fin with 5 to 6 rays, its position slightly backward in respect to the second anal fin; two anal fins, the first with 13 to 18 rays, the second with 5 or 6 rays and very similar in size and shape to the second dorsal; pectoral fins long and narrow, with pointed tips, adpressible against sides of body and with 18 to 22 rays; pelvic fins slender and almost equal to, or slightly shorter than the pectorals in large specimens, and slightly longer than pectorals in smaller individuals. Caudal peduncle well compressed (laterally) and slightly depressed (dorsoventrally), with a pair of keels on each side and a shallow notch on both, the dorsal and ventral surfaces; anus situated just in front of first anal fin origin. Lateral line single and obvious, curving above base of pectoral fin and then continuing in a straight line toward the caudal fin base. Body densely covered with elongate bony scales, each with 1 or 2 posterior points. Vertebrae 24 (12 precaudal and 12 caudal). Colour: body blue-black dorsally and silvery white ventrally, with about 15 rows of cobalt-coloured stripes, each consisting of round dots and/or narrow bands. First dorsal fin dark blue; other fins usually dark brown, sometimes tinged with dark blue; bases of first and second anal fins tinged with silvery white.

In the period from 1978 to 1982, catches of T. audax have been reported from seven FAO Fishing Areas (51, 57, 617 71, 77, 81 and 87), mostly by Japan and the Republic of Korea. The total world catch was 15 426 t in 1978, 15 988 t in 1979, 18 429 t in 1980, 15 664 t in 1981 and 15 460 t in 1982. Only 13.6% (2 132 0 of the 1981 total catch was taken in the Indian Ocean, and 86.4% (13 532 t) in the Pacific Ocean, particularly in Fishing Area 61 (northwest Pacific) with 7 229 t predominantly by Japan, in Fishing Area 77 (eastern central Pacific), with 2 414 t predominantly by Japan, and in Fishing Area 87 (southeast Pacific) with 2 217 t by Japan and the Republic of Korea (FAO, 1983); of the 1982 catch, 12.6% (1 949 t) was taken in the Indian Ocean and 87.6% (13 511 t) in the Pacific Ocean, predominantly by Japan, China (Taiwan Province) and the Republic of Korea (FAO, 1984). The commercial catch of T. audax is taken mostly by surface longlining, while harpooning may be responsible for less than 1% of the total catch in recent years. The longliners aim chiefly at tunas and marlins which are frequently swimming at depths between 100 and 150 m. Longline gear consists of a mainline, float lines, branch lines, hooks, bouys including several radio-bouys, and flags. Several hundred of these units (each unit is referred to as a "basket") are joined in a series to make up a set of longline. The longline is retrieved with a line hauler. Japanese longliners in the eastern Pacific use about 2 000 hooks (about 400 baskets) per set. Due to recent manpower problems, considerable effort has been directed toward developing labour-saving devices in longlining. The reel-type and the tub-type of longlining are two examples of this development. In the reel-type the mainline (usually wire) is continuous and reeled onto a large drum, while in the tub-type, the retrieved line is coiled into a large tub. In harpooning, the electric harpoon has been recently introduced in Japanese fisheries to speed up the killing of the fish. The total catch reported for this species to FAO for 1999 was 9 717 t. The countries with the largest catches were Japan (5 532 t) and Taiwan Province of China (2 696 t). The quality of the flesh is the best among billfishes for sashimi and sushi. It is marketed mostly frozen, sometimes fresh.

T. audax occurs mainly in the tropical, subtropical and temperate waters of the Pacific and Indian oceans. Japanese long line catch data collected over many years show that the distribution pattern of this species within the Pacific Ocean is horseshoe-shaped, with the base of the horseshoe located along the Central American coast. T. audax is occasionally found on the Atlantic side of the Cape of Good Hope (Talbot & Penrith, 1962) and one individual was caught off Angola, West Africa in October 1976, having probably strayed from the Indian Ocean as in a few cases of Tetrapturus angustirostris and Makaira indica. The latitudinal range limits of T. audax, based on data from the commercial longline fishery, extend from about 45° N in the North Pacific to 30° S in the eastern South Pacific and to 45° S in the western South Pacific, as far south as 45° S in the southwestern Indian Ocean and 35° S in the southeastern Indian Ocean.

The maximum size attained by this species exceeds 350 cm in total length and 200 kg in weight. The all tackle angling record is a fish caught off the Cavalli Islands, New Zealand, on 14 January 1977, weighing 189.37 kg (417 lb 8 oz). Other records of large specimens (over 180 kg) are the following: 183.47 kg (404 lb 8 oz), Bay of Islands, New Zealand, on 12 March 1980; 181.89 kg (401 lb), Cavalli Islands, New Zealand, 24 February 1970; 180.53 kg (398 lb), Mayor Island, New Zealand, 30 December 1974 (IGFA, 1981). All world records for both men and women recognized by IGFA are from New Zealand, except a record from Botany Bay, Sydney, on 24 October 1976 (161.93 kg=357 lb for men's 30 lb line class). Size at first capture (longline fisheries) of T. audax is approximately 80 cm eye-fork length (= 83.9 to 86.1% of body length). Around Taiwan Island, size at first maturity is generally estimated between 140 cm and 160 cm eye-fork length, and the biological minimum size of males at about 137 cm eye-fork length. The maximum size in commercial fisheries is probably about 290 cm eye-fork length or 258.6 kg (570 lb). The sizes of fish taken by commercial longliners range mainly from 205 to 225 cm body length in the northern part of the western North Pacific, between 145 and 185 em body length in the southern part of the western North Pacific, between 235 and 255 cm body length in the central North Pacific, and about 280 cm body length in the western South Pacific.

This is an epipelagic andoceanic species,usually swimming above the thermocline. Parin (1968) included it among the holoepipelagic species which inhabit the isothermic, surface-pelagic layer of the ocean at all stages of their life cycle, and are usually confined to tropical and subtropical waters where permanent thermoclines exist, but penetrate higher latitudes in the local warm seasons. However, the striped marlin has a somewhat atypical distribution as compared to most other billfishes and tunas, and seems to prefer more temperate waters. In the Pacific, its distribution resembles that of the albacore (Thunnus alalunga ) and the bluefin tuna (Thunnus thynnus ), in contrast to that of the other billfishes and tunas. In the Indian Ocean, however it is found in warmer waters. The total distributional range of this species, is generally bounded by the 20° and 25° C isotherms, at least in the western Pacific Ocean. This is the most dominant and widely distributed of all billfishes, especially in the eastern and northcentral Pacific, where it is much more abundant than in the western Pacific. In the Indian Ocean, the striped marlin is abundant in the western Arabian Sea. Larvae of striped marlin have been recorded from the western North Pacific west of 180° long.) between 10° to 30° N, and from the central South Pacific (west of 130° W) between 10° and 30° S. They are most abundant in the respective local early summers, with peak occurrences during May through June in the western North Pacific, and in November and December in the central South Pacific. The seasonal occurrence of mature females coincides with that of the larvae. While the distribution of larvae for the eastern Pacific (east of 120° W) is not known, mature fish are reported to occur there between 5° and 20° N, largely in May and June. Larvae have also been reported to occur in the Banda and Timor seas in January and February, in the eastern Indian Ocean in October and November between 6° N and 6° S, and in the western Indian Ocean between 10° S and 18° S in December and January. Mature females are found in March and May in the Bay of Bengal, although larval occurrence is not yet known there.The lower temperature limit in the distribution of larvae is approximately 24° C, both in the Indian and Pacific oceans. However, larval distributions in the two oceans differ in that, in the Pacific, the larvae of this species are scarcely found in equatorial waters. It has been noted that larvae of T. audax are not likely to appear in the Kuroshio Current area, while those of the Indo-Pacific sailfish, Istiophorus platypterus occur there extensively. Two juveniles of striped marlin (12.2 and 14.5 cm body length) were found in stomachs of a yellowfin tuna (Thunnus albacares ), and of a dolphinfish (Coryphaena hippurus ) taken by longlines on 13 January 1955 at 23°52' S/175°49' W and on 21 December 1964 at 17°5' S/67°29' E. These two occurrences coincide with larval distributions of the species in the South Pacific and Indian oceans, respectively. The ovarian eggs of striped marlin from New Zealand average about 0.85 mm in diameter shortly before spawning. The size of ovulated eggs is presumed to exceed 1 mm in diameter, considering that the mean diameter of the eggs of the shortbill spearfish (Tetrapturus angustirostris ) is 1.442 mm and that the eggs of the Indo-Pacific sailfish (Istiophorus platypterus ), measure 1.304 mm in diameter. T. audax, like the other marlins, does not form dense schools like the tunas, and the individuals are usually dispersed at considerably wide distances. Several fish, however, are often seen together, sometimes following one another, especially during the spawning season. Surfacing is apparently more common with strong wind and high waves. When wind and current are moving in the same direction, the water surface is rather smooth, but when the wind runs against the current, high waves develop and this is when striped marlin are most often seen at the surface around Taiwan Island, usually swimming in the direction of the wind. When surfaced, striped marlins usually swim very slowly, with the upper caudal fin lobe above the surface and the dorsal fin retracted and not showing, a characteristic which reportedly distinguishes thern from swordfishes which are unable to depress the dorsal fin and show both the dorsal and caudal fins when surfaced. Striped marlins swim faster and are less easily approached when surfaced than the swordfish. Like other billfishes and tunas, they tend to school by size. [more...] Dolphinfishes (Coryphaena spp.), wahoo (Acanthocybium solandri ) and the pelagic large sharks (Prionace, Isurus, Lamna, Carcharhinus and Alopias ) feed on many of the same forage organisms as the striped marlin. Its closest competitors for food are possibly the other billfishes and larger tunas. The striped marlin, however, tends to feed more on epipelagic organisms and less on mesopelagic ones than the swordfish and the oceanic tunas. Food habits do not appear to vary significantly with sex or size, at least in adults. Considerable variation in species composition of the diet occurs, however, with seasons and geographic localities. T. audax, like other billfishes and tunas, is thought to be carnivorous and a non-selective feeder. Some of its reported major forage species by localities are: Fistularia sp., Auxis sp., squid (East Africa); Scomberoesox saurus, Arripis trutta, Loligo sp., Ommastrephes sloani, Caranx lutescens, Scomber japonicus (New Zealand); Alepisauridae, Clupeidae (Tasman Sea); Gempylus serpens, Cololabis saida, Engraulis mordax, Sardinops caerulea, Trachurus symmetricus (California); Etrumeus teres, Fisturalia sp., Argonauta sp., squid Mazatlan, Mexico, Etrumeus teres, Scomber japonicus, Fistularia sp., squid (Baja California, Mexico); Auxis spp., Bramidae, Gempylidae, squid (eastern North Pacific); Alepisaurus spp., squid (eastern South Pacific); squid (Peru-Chile); Engraulis rinqens, Trachurus symmetricus, squid (Chile).Predators of adults of this species are probably extremely rare or almost inexistent, the only likely candidates being some of the large pelagic sharks and the toothed whales, although there are many predators to the earlier life-stages of the striped marlin.

Females are indeterminate batch spawners with asynchronous oocyte development (Ref. 92477). Larvae are most abundant in the respective local early summers. The seasonal occurrence of mature females coincides with that of the larvae. The lower temperature limit in the distribution of larvae is approximately 24°C, both in the Indian and Pacific Oceans.Spawning sites are between 10°S and 30°S in Southwest Pacific and 10°S and 20°S in northeastern Indian Ocean (Ref. 6390).

Oceanodromous. Migrating within oceans typically between spawning and different feeding areas, as tunas do. Migrations should be cyclical and predictable and cover more than 100 km.

Dorsal spines (total): 0; Dorsal soft rays (total): 42 - 48; Analspines: 0; Analsoft rays: 18 - 24

There is little information on the distribution of striped marlin eggs and larvae (Ref. 6390). Juveniles are relatively rare in the southwest Pacific Ocean (Ref. 30443). Fish of 4-10 kg (80-100 cm FL) are regularly caught on longlines in the region but concentrations of fish this size are most restricted to the northcentral Pacific Ocean (Ref. 30443).Striped marlin are carnivorous, non-selective feeders whose diet includes more epipelagic organisms than the diets or other billfish and larger tunas (Ref. 6390). Their diet changes with season and locality (Ref. 6390).

Body elongated and compressed; upper jaw produced into a robust and medium sized beak; two dorsal fins, the height of the first greater than the greatest depth, short anteriorly, taller in the middle, then becoming shorter posteriorly; pectoral fins falcate and flexible, with 18 to 22 rays; body densely covered by small, embedded scales with 1 or 2 bluntish points; back dark blue; belly silvery; membrane of first dorsal fin blue black without dark spots; flanks with about 20 bluish stripes (Ref. 55763). Blue-black above and silvery white below, with about 15 rows of cobalt-colored stripes; 1st dorsal fin dark blue; other fins dark brown, sometimes with a tinge of dark blue; anal fin bases with a tinge of silvery white.

Epipelagic and oceanic species, usually found above the thermocline. Generally inhabit cooler water than either black (Makaira indica) or blue marlin (M. mazara) (Ref. 43). Most dominant and widely distributed of all billfishes. Their abundance increases with distance from the continental shelf (Ref. 6390). Usually seen close to shore only where deep drop-offs occur (Ref. 6390). Mostly solitary, but form small schools by size during the spawning season (Ref. 9987). They are usually dispersed at considerably wide distances. Feed on fishes, crustaceans and squids. Also caught with the harpoon. The flesh is the best among billfishes for sashimi and sushi. Marketed mostly frozen, sometimes fresh (Ref. 43); also smoked and frozen (Ref. 9987). Also Ref. 9137, 9574.

fisheries: commercial; gamefish: yes

廣泛分布於印度洋及太平洋之熱帶、亞熱帶海域，少數會進入溫帶海域，有些會越過好望角而進入大西洋。主要分布於東部海域。

經濟性魚種，全世界產量在500-2,000公噸。常用延繩釣或鏢旗魚法捕獲。紅肉旗魚的肉正如其名是紅色的，可以作生魚片，外銷到日本賺取外匯，也可以油炸或炒排骨食之。

體延長而極側扁；尾柄細而強狀，具二隆起脊。頭較長；吻長而尖，明顯較下頜突出。口大，微斜裂。頜齒呈絨毛狀齒帶，鋤骨無齒。體被細長骨質鱗；側線單一，平直至尾部。第一背鰭軟條部等於或略高於體高，大部分軟條由前而後大致逐漸短小；第二背鰭短小；胸鰭位低，呈鐮刀狀，幾等長於腹鰭；腹鰭胸位，起點在胸鰭基底下方，向後不延伸至肛門；尾鰭深叉形。體背褐色，腹部銀白色，體側具白色橫帶。第一背鰭藍黑色而具黑斑，此斑隨成長而消失；腹鰭藍黑色；尾鰭暗色。以前所記載之/Tetrapturus audax/為同種異名。

大洋性中上層洄游性魚類，一般皆發現在躍溫層之上的水域，較少成群出現於沿岸水域。游泳速度快。具繁殖洄游之習性。主要攝食魚類、甲殼類及頭足類等。

The striped marlin (Kajikia audax) is a species of marlin found in tropical to temperate Indo-Pacific oceans not far from the surface. It is a desirable commercial and game fish. The striped marlin is a predator that hunts during the day in the top 100 m or so of the water column, often near the surface. One of their chief prey is sardines.