Shortfin MakoIsurus oxyrinchus
This classically shaped shark is incredibly hydrodynamic from its pointed snout to its triangular dorsal fin and large, crescent caudal (tail) fin. It is a dark metallic blue on top and silvery white below, with a very distinct color break down its side. The average size is 10 feet long and 300 pounds, but they have been caught at well over 12 feet and 1,000 pounds. Because the shortfin mako is an impressive apex predator, and the fastest shark, clocking speeds of 20 mph, it is a sought-after sport fishing catch, and is now listed as a vulnerable species.
Order - Lamniformes
Family - Lamnidae
Genus - Isurus
Species - oxyrinchus
The shortfin mako's common name is derived from the Maori term mako, which translated means "shark". Other common names referring to this shark include al karch (Arabic), amlez (Hebrew), anequim (Portuguese), anequin barbatana curta (Portuguese), aozame (Japanese), aso-polota (Samoan), atlantic mako (English), atunero (Spanish), blauhai (German), bleu pointu (French), blue pointer (English), blue shark (English), bonito shark (English), cação-atum (Portuguese), canavar baligi (Turkish), cane de mare (Spanish), carcharias, carito (Spanish), cawar (Somali), chlarm (Khmer), deeba (Arabic), dentuda (Spanish), dentuse (Spanish), diamante (Spanish), dientuse (Spanish), dientuso azul (Spanish), dikburun (Turkish), dikburuncanavar baligi (Turkish), dog shark (English), ganumu sora (Telugu), gisandoo (Wolof), haai (Dutch), haringhaai (Dutch), janequín (Spanish), kortvin-mako (Afrikaans), kortvinmakreelhaai (Dutch), lamie (French), mackerel porbeagle (English), mackerel shark (English), mako (English), mako shark (English), makrelenhai (German), ma'o a'ahi (Tahitian), marache (French), marracho-azul (Portuguese), marrajo dientuso (Spanish), ngutukao (Maori), ossirina (Italian), pointed nose shark (English), requin-taupe bleu (French), sharpnose mackerel shark (English), shortfin shark (English), snapper shark (English), solraig (Catalan), spitssnuitmakreelhaai (Dutch), squalo mako (Italian), and taupe bleu (French).
Importance to HumansDue to its beauty, aggressiveness, and jumping ability, the shortfin mako is considered one of the great gamefishes of the world. Shortfin makos are caught with trolled baits and lures as well as with live or dead baits fished from anchored or drifting boats.
Highest recreational catches occur off southern California, the northeastern United States, Australia and New Zealand. The shortfin mako was made famous in Ernest Hemingway's The Old Man and the Sea. Hemingway also caught a 786 pound mako with a rod and reel off Bimini, the Bahamas, in 1963. It is a highly sought after commercial species as well. Its flesh is flavorful and limited quantities may be found in the United States markets, including California where it sometimes is sold as swordfish. Commercial captures are made using longlines, stationary gill nets, and drift nets. The fins and liver oil are also marketed. Shortfin makos are a major by-catch component of the tuna and swordfish fisheries.
Danger to Humans
Although oceanic species, the shortfin mako's power, aggressiveness, teeth and great speed, make it a danger to humans. Shortfin makos have been blamed for a number of nonfatal and fatal attacks on humans. Divers who have encountered shortfin makos note that they swim in a figure eight pattern and approach with mouths open prior to an attack. Shortfin makos frequently damage boats and injure fishers after being hooked.
The world's affinity for shark fin soup and the delectable flesh of the shortfin mako has lead to a decrease in population numbers. Worldwide, the shortfin mako is not only subject to overharvesting by direct hunting, and they are often by-catch victims of the tuna and swordfish fishing industries. As a result, the U.S. National Marine Fisheries Service (NMFS) has included the shortfin mako on their list of managed pelagic sharks. The NMFS has reduced the number of commercial and recreational shortfin mako catches allowed per year by 50% in an attempt to counter act its declining numbers. However, the NMFS regulations apply only to the United State's Atlantic and Gulf waters. Also hastening their population decrease is their slow reproductive rate.
The IUCN is a global union of states, governmental agencies, and non-governmental organizations in a partnership that assesses the conservation status of species.
Geographical DistributionThe shortfin mako has a wide distribution. It is found in tropical and temperate waters throughout the world's oceans. In North America it ranges from California to Chile in the Pacific and from the Grand Banks to the hump of Brazil, including the Gulf of Mexico and the Caribbean Sea in the Atlantic. It is commonly seen in offshore waters from Cape Cod to Cape Hatteras. In the eastern Atlantic the shortfin mako ranges from Norway to South Africa, including the Mediterranean and it is found throughout the Indian Ocean from South Africa to Australia. In the western Pacific it ranges from Japan to New Zealand and in the central Pacific it occurs from the Aleutian Islands to the Society Islands.
The shortfin mako is a true pelagic species with a primarily anti-tropical distribution. However, they will enhabit the cooler, deeper water of tropical regions. In some tropical areas where the surface temperature is 27°C (81°F), water temperature may be as low as 59°F (15°C) at depths of 30-60 m (94.2-188.4 ft). With the ability to elevate body temperature, makos are able to maintain themselves in temperatures of 5-11°C (41-52°F). In this sense the makos are somewhat "warm-blooded," meaning that heat in their blood is conserved within the body and not lost through the gills. They have been recorded at depths 740 m. However, shortfin makos prefer water temperatures between 17-20°C. It has been hypothesized this species migrates seasonally to warmer waters. This theory has been supported by tag and release studies.
These studies have also shown that while shortfin makos follow warm water, they do so within the confines of a specific geographical area. Consequently, there seems to be limited genetic flow between these geographically distinct populations. Very little is known about the social habits of the shortfin mako, except that it is a solitary shark.
1. Snout is conical and pointed
2. Teeth are long and protrude from the mouth
2. Caudal fin is lunate with a single keel on the caudal peduncle
The shortfin mako body is conic-cylindrical and and extremely hydrodynamic. The snout is bluntly pointed with large black eyes. The caudal keel is prominent and the caudal fin is lunate. The tail has a high aspect ratio (ratio of height to length), which produces maximum thrust with minimum drag and provides almost all of the propulsion for the shark. The anteroventral zone of the snout is black. There are two extant (living) mako sharks, the longfin mako (Isurus paucus) and the shortfin mako (Isurus oxyrinchus). The longfin mako resembles the shortfin mako, but has larger pectoral fins and larger eyes. The presence of only one lateral keel on the tail and the lack of lateral cusps on the teeth distinguish the makos from the closely related porbeagle sharks of the genus Lamna.
Color is brilliant metallic blue dorsally and white ventrally. The line of demarcation between blue and white on the body is distinct. The underside of the snout and the area around the mouth are white.The latter is important because is helps differentiate the shortfin from the longfin mako, which has a darkly pigmented mouth region.Color is related to size. Larger specimens tend to possess darker color that extends onto parts of the body that are white in smaller individuals. The juvenile mako differs in that it has a clear blackish stain on the tip of the snout.
The mouth is parabolic, or bowl-shaped, with the first teeth of the lower jaw aligned in a continuous row. The large, triangle-shaped, narrow hooked teeth have razor-sharp smooth edges. They are blade-like without basal cusps or serrations. Teeth of both the upper and lower jaw are roughly uniform in size and shape with the first two teeth on either side of the mandibular symphyses being longer and more slender than the rest. Teeth of the lower jaw are visible even when the jaw is shut while the upper teeth remain partially hidden except when the jaw is projected outwards.
Denticles are small and overlapping, with 3 to 5 ridges, and 3 marginal teeth. The middle marginal tooth is the longest and appears more worn down in comparison.
Size, Age & Growth
Average adult size is 3.2 m (10 ft) and 60-135 kg (135-300 lbs). As with most shark species, females are larger than males and may reach 380 cm (12.5 ft) and weigh 570 kg (1,425 lbs). The largest "mako" taken on hook and line worldwide was 505.76 kg (1115 lbs), however no positive species identification was made (shortfin or longfin mako). The shortfin mako has a growth rate that exceeds other lamnids. Length analyses, as well as counts of growth rings on vertebral centra have been utilized in studies to estimate the age of this species. Shortfin makos likely live about 20 years.
The shortfin mako is the fastest shark, capable of attaining speeds of up to 32 km/h (20 mph), and leaping skillfully out of the water. The mako holds the speed record for long distance travel: approximately 2130 km (1320 miles) in 37 days for an average of about 58 km (36 miles) per day. The shortfin mako feeds on other fast-moving pelagic fishes such as swordfish, tunas, and other sharks as well as squid. The stomach contents of sharks caught in gillnets off Natal, South Africa, showed a 60 to 40 ratio of shark to bony fish, while a study from the northeastern United States found 77.5 percent of the mako diet was bluefish. Marine mammals and sea turtles are rarely ingested by this species.
Despite being a top predator, shortfin makos run the risk of physical harm when hunting prey. There have been many reports of captured sharks bearing scars apparently due to encounters with swordfishes. One mako recovered from a net was impaled through the eye with the bill of the swordfish.
Shortfin makos are slow growing with males reaching maturity at at least 8 years of age and females not before 18 years of age. This, along with a three-year reproductive cycle, indicates that this species is quite vulnerable to the pressures of overfishing. Development is ovoviviparous. Embryos in the uterus are nourished by yolk stored in a yolk sac. There is no placental connection between mother and young. Once the young are hatched into each uterus, uterine cannibalism (known as oophagy) occurs. Oophagy is the ingestion of unfertilized or less developed eggs by a fetus that is more developed. Young are born after 15-18 month gestation period. Litters range from 8-10 pups measuring 68-70 cm (27-28 in). Upon capture, pregnant females usually abort embryos, therefore few specifics about reproduction are known.
Larger sharks may feed upon juvenile shortfin makos. Adult makos likely fall prey only to humans.
Shortfin makos host a variety of parasitic copepods. These are found on the skin, in the mouth, and on the fins. Species recorded from the shortfin mako include Dinemoura latifolia, Echthrogaleus denticulatus, Pandarus smithi, Anthosoma crassum, and Nemesis lamna.
Rafinesque first described this shark as Isurus oxyrinchus in 1810. Since then, it has also appeared in the literature as Isurus spallanzani Rafinesque 1810, Oxyrhina glauca Müller & Henle 1839, Isuropsis dekayi Gill 1862, Isurus makoWhitley 1929, and Isurus africanus Smith 1957 as well as many others. The species name oxyrinchus is translated from Greek "oxy" = sharp and "rynchus" = nose. Isurus is Greek for equal tail referring to its lunate caudal fin.
Prepared by: Nancy Passarelli, Craig Knickle and Kristy DiVittorio