The mako is the quintessential shark. It is probably the most graceful of all sharks, the most beautifully proportioned, the fastest, the most strikingly colored, the most spectacular game fish, and one of the meanest-looking animals on earth.
Like other mackerel sharks, the great white and the porbeagle, the mako has a homocercal (equal-lobed) tail, and a horizontally flattened keel at the tail’s base. They all are gracefully streamlined, with a conical snout, dark eyes, small second dorsal fins, and the aforementioned tail shape. The dark eyes give them a look of intense intelligence that they may not possess, as well as the bold look of another group of superbly designed predators, the falcons.
The keels of the mackerel sharks are fascinating and mysterious structures. They show a compression in the dorso-ventral plane of the entire base of the tail, also called the caudal peduncle. It is assumed that this modification is related to speed and power in swimming, since it significantly adds to the musculature of the tail structure, the shark’s means of propulsion. Among the sharks, the mackerels show the most pronounced keels, but other species, not normally associated with fast movement, also have this modification. The whale shark and the basking shark, two plankton feeders that are characterized by slow and ponderous movements, have keels on their tail structure, and the tiger shark, not known for speed, also shows this characteristic. Many of the scombroid fishes (tuna, mackerel), and the billfishes (marlin, sailfish), have one or more small keels, but the broadbill swordfish is the only teleost that shows a development that is in any way similar to that of the mackerel sharks. In my paintings of the mako I have tried to show this unique structure by “twisting” the shark, rather than painting it in profile.
Another characteristic that separates the isurids from all other elasmobranchs is their ability to conserve body heat and maintain a body temperature that is considerably higher than the ambient water. It has long been known that certain scombroid fishes, especially tuna, have this ability, but in 1968 two Woods Hole biologists, Carey and Teal, were the first to mention this phenomenon in sharks. Only makos and porbeagles were tested, but white sharks, the third member of the family, were examined, and showed the same structural modifications, so it is safe to assume that they share this ability. According to Carey and Teal, heat is conserved by a “set of countercurrent heat exchangers located in the circulation between the gills and the tissues. The heat exchangers form a thermal barrier which permits the flow of blood but blocks the flow of heat.” The authors conclude that there is a threefold increase in the muscle power for every ten degrees Centigrade rise in body temperature. A mako that can jump fifteen to twenty feet in the air requires a starting velocity of 22 miles per hour.
The reproduction and parturition of the mako and the porbeagle are thought to be similar. A pregnant mako has been examined, and it was found to contain ten embryos, five male and five female, ranging in size from 25 inches to 27.5 inches. It can be assumed that these embryos were close to term, since there have been free-swimming makos caught that were 31.5 inches long. According to Bigelow and Schroeder, porbeagles are ovoviviparous (eggs hatch in the female, and are not otherwise attached), and they are nourished in utero by “swallowing unfertilized eggs which lie close to it in the uterus, the result being that the stomach becomes enormously swollen by the masses of yolk so swallowed, forming a so-called ‘yolk stomach.’ ” We can suppose that the same applies to makos.
Almost all sharks are dark above and lighter below, but few show the dramatic contrast between the rich ultramarine dorsal surface and snowy underbelly of the mako, often separated by a band of silver. A profile portrait of the mako shows this shark to best advantage, emphasizing the conical snout which is so uniquely pointed. This characteristic has resulted in one of its vernacular names, sharpnose mackerel shark. Other common names include blue pointer, mackerel shark, and bonito shark. Makos have particularly long teeth, which are not serrated like those of their infamous cousin, the great white, nor are they cusped like those of their relative, the porbeagle. The teeth of a big mako are huge, resembling curved knives set into the jaw. They are also flattened on the forward surface, which increases this knifelike impression. Smaller specimens have more rounded teeth, so it takes a big mako to display the full and frightening implications of these teeth. Ernest Hemingway had obviously seen big makos, and he describes one in The Old Man and the Sea
The teeth of most sharks are laid back when not in use, and the opening of the mouth brings them into an upright position. This occurs to a limited extent with the mako, but its lower teeth are always erect and serve to give this shark, in life as well as in death, a snaggletoothed and fearful visage. It is the stuff of which nightmares are made. For the big game fisherman, mako fishing is the stuff of which dreams are made. Capable of spectacular gymnastics and at the same time one of the few fish whose actions can be decidedly aggressive, the mako brings an added dimension to game fishing. It is difficult at best to judge heights from the water, but there seems to be a general consensus that a fighting mako can jump at least twenty feet out of the water. Makos charge boats, sometimes jump right into them, and generally provide a level of excitement beyond that of the ordinary game fish experience. In mako fishing, you might lose not only your fish, you might lose your rod or even your arm. It is perhaps the only type of big game fishing where there is a real element of personal danger.
Makos are worldwide in distribution, favoring tropical and temperate waters. They do not school, and they are never seen in very large numbers. Like the porbeagle, the mako tends to inhabit deeper waters than the great white.
One final note about the mako’s swimming style, by comparison to blue sharks: Blue sharks are slim, sinuous swimmers, turning and twisting by using their long, curved pectoral fins. By contrast, the mako is a stiff-bodied swimmer, propelling itself through the water with short strokes of its thick, powerful tail. When seeing a mako in its own element, one has the overall impression of blue muscular efficiency.
The shortfin mako shark, Isurus oxyrinchus, (”sharp nose”) is a large shark of the Lamnidae family. Along with the closely related longfin mako, Isurus paucus, it is commonly called just mako shark.
Anatomy and appearance
A shortfin mako shark.
A close-up of a shortfin mako shark’s head.With a full-grown length of 2.75 – 4 m (9 – 13 ft) it has been reported to weigh up to 800 kg (1,750 lb) and has a bluish back and white underside. Although the sexes grow at about the same rate, females are thought to have a longer life span, and grow larger and weigh more than the males. Shortfin makos are renowned for their speed and their ability to leap out of the water. In fact, there are cases when an angry mako will jump out of the water and into the boat after it has been caught on the hook. Mako sharks have a better hydrodynamic shape than all other sharks, and this, combined with the lamnidae’s typical high aerobic muscle mass, reflects in the spectacular speed and agility of both the longfin and shortfin makos[citation needed].
The shortfin mako shark is a sleek spindle shaped shark with a long conical snout. This shark has short pectoral fins and a crescent shaped caudal (tail) fin. There is a distinct caudal keel on the caudal base. Its second dorsal fin is much smaller than the first. The teeth are slender and slightly curved with no lateral cusps, and are visible even when the mouth is closed. There is marked countershading on this shark: dorsally it is a metallic indigo blue while ventrally it is white.
Naming
The name “mako” comes from the M?ori language, but the etymology is unclear.[2] A typical gloss given for “mako” is “large blue shark”. The term entered the English language in 1727. It can also mean “man-eater”.
Diet
The shortfin mako feeds mainly upon bony fishes including mackerels, tunas, bonitos and swordfish, but may also eat other sharks, porpoises and sea turtles.
Distribution
The shortfin mako is found in temperate and tropical seas worldwide. The closely related longfin mako shark, Isurus paucus, is found in the Gulf Stream or warmer offshore waters.
Shortfin mako sharks live in tropical and temperate offshore waters. They are a pelagic species that occur from the surface down to depths of 150 meters (490 feet). This shark is seldom found in waters colder than 16 degrees Celsius.
The shortfin mako is found worldwide. In the western Atlantic it can be found from Argentina and the Gulf of Mexico to Browns Bank off of Nova Scotia. In Canadian waters these sharks are not abundant as they prefer warm waters, but neither are they rare. Shortfin makos are often found in the same waters as swordfish as they are a source of food and both fish prefer similar environmental conditions.
Behavior
The shortfin mako’s speed has been recorded at 50 km/h (31 mph) and there are reports that it can achieve bursts of up to 74 km/h (46 mph).[4] Shortfin makos can jump up to 9 m (28 ft) in the air. Due to its speed and agility, this high-leaping fish is sought as game worldwide. This shark is highly migratory. They are also one of four warm-blooded sharks which helps them in their speed.
There is still some uncertainty about its life-span, but it is suspected to reach ages of between 11-23 years.
Reproduction
The shortfin mako shark is a yolk-sac ovoviviparous shark, meaning it gives birth to live young who feed from a sac full of yolk in the womb. The gestation period for a mako shark is 15 to 18 months. Shortfin mako embryos in the female’s body consume each other to get nutrients. This is called intrauterine cannibalism.
Female shortfin makos usually become sexually mature at a length of 3 meters. Developing embryos feed on unfertilized eggs in the uterus during the gestation period of 15-18 months. The 4-18 surviving young are born live in the late winter and early spring at a length of about 70 cm, but have no placental connection during development (ovoviviparity). It is believed that females may rest for 18 months after birth before the next batch of eggs are fertilized.
Trivia
Distinguishing characteristics
• Teeth are visible even when the mouth is closed
• Teeth are long and slender with smooth-edged cusps
• Distinct countershading, dorsally blue and ventrally white
• Moderately short pectoral fins
• Underside of the snout is white
• Lunate tail and caudal keel