The mako shark (Isurus oxyrinchus), also known as the shortfin mako or blue pointer, is a type of elasmobranch belonging to the family Lamnidae. It can reach between 3.5 and 4 meters in length. It has a very wide distribution:: it is found in the Pacific, Atlantic, and Indian Oceans, as well as in the Mediterranean Sea, the Caribbean Sea, and the Red Sea. It is considered endangered due to overfishing.
Classified as globally vulnerable (IUCN 2014), this shark has experienced high fishing mortality in the North Atlantic. It is estimated, according to a demographic modeling analysis, that its abundance has decreased by between 20 and 80% (Kyne et al. 2012). Historical catch data from the Venezuelan industrial longline fishery show a gradual decline in numbers over the past years (Tavares and Arocha 2008, Arocha et al. 2013). Due to the vulnerability of its populations, the International Commission for the Conservation of Atlantic Tunas has urged contracting nations to implement efforts to reduce fishing mortality.
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General Characteristics
The shortfin mako is a large shark with a fusiform, robust, and very hydrodynamic body. Its snout is conical and pointed, and its mouth is large and narrow, U-shaped, with wide spaces between the jaws. The eyes are round, black, and medium-sized.
Fins
It has medium-sized pectoral fins with slightly rounded ends. The first dorsal fin is medium, also with rounded ends, and originates just behind the pectoral fins; the second dorsal and the anal fins are tiny and are positioned opposite each other. The caudal fin is large, with wide crescent-shaped lobes, with the upper lobe slightly larger than the lower. It has five pairs of large gill slits. The caudal peduncle is depressed and widened by large, very long lateral keels.
Like other sharks in the Lamnidae family, shortfin makos maintain a body temperature higher than the surrounding environment (they are homeothermic), which allows them to digest food more quickly, increase their muscle strength, and react more rapidly. It is a pelagic shark with oceanic habits.
Teeth
The teeth are large, with broad cusps (in adults) and curved, with smooth edges; the third upper tooth is tiny and inclined, followed by a gap. Its coloration is dark blue on the back, lighter on the sides, and white on the belly.
Size
These are large sharks, with a female recorded at 4.5 meters in length. The usual size of well-developed adult specimens is between 3.5 and 4 meters, with weights of up to 750 kg.
Longevity: How Long Do They Live?
The shortfin mako shark (Isurus oxyrinchus) can live for more than 30 years. This shark grows slowly and reaches sexual maturity at a late age: around 8 years for males and between 19 and 21 years for females. Due to its slow growth and late maturity, combined with its low reproduction rate, it is especially vulnerable to fishing pressures and other anthropogenic factors.
Reproduction
The blue pointer is an ovoviviparous shark, with litters of between 4 and 8 pups, with the maximum known being 16. These small sharks are about 70 centimeters long at birth and will grow according to their sex, maturing at 1.9 meters for males and 2.6-2.8 meters for females.
When a blue pointer has pups in its belly, the more developed embryos or larger pups eat their siblings and eggs in a cannibalistic activity called oophagy.
The reproductive cycle of the mako shark is triennial, with a gestation period of approximately 18 months. Mako sharks give birth to live pups, which is characteristic of their ovoviviparous reproduction. These pups are born at a considerable size, increasing their chances of survival by reducing the number of potential predators.
Due to their longevity and other biological factors, the management and conservation of mako shark populations require a careful and sustained approach to ensure their long-term viability. Population assessments and fisheries management measures are essential to mitigate the effects of overfishing and ensure the recovery of declining populations.
Diet: What Does It Eat?
This shark is a powerful and fast hunter of a wide variety of prey. Its diet includes small fish like mackerel, herring, jack mackerel, sardine, bonito, skipjack, and little tunny, as well as larger fish such as bluefin tuna, swordfish, marlins, and sailfish. It also feeds on squid, other sharks, sea turtles, porpoises, and dolphins. There have even been cases of attacks on small cetaceans due to its large size and aggressiveness. It is the primary predator of the swordfish (Xiphias gladius), which makes up a significant part of the diet of large makos. There is a case of a mako weighing over 300 kg being captured with a 55 kg young swordfish found whole in its stomach.
Danger
Due to its large size, dentition, and aggressiveness, they are considered dangerous sharks and there have been a number of attacks, both provoked and unprovoked. It is also responsible for attacks on boats, sometimes jumping inside, especially during sport fishing.
The mako shark is known to have attacked people and boats without prior provocation, so it is considered quite dangerous. It is highly prized by sport fishing enthusiasts due to its combative nature and great power.
Despite its voracity and danger, the mako is not at the top of the food chain, as the orca is a natural predator of this fish. There have been cases in New Zealand waters where an orca destroyed a mako, striking it with its tail. However, the mako manages to avoid being preyed upon by the great white shark, the other great marine predator, due to the different habitats they frequent; while the great white shark is more common in warm, shallow waters, the mako is typically found in deep waters.
Speed
The mako shark can reach speeds of up to 70 km/h (Fernandez-Waid et al., 2019). The secret to this power and speed lies in its morphology, which provides excellent hydrodynamics, and its powerful muscle mass. This combination of strength and speed allows it to leap very high out of the water, much like the great white shark. It often makes these jumps when hooked on a fishing line, reaching heights of 3 to 4 meters.
Intelligence
Of all the sharks studied, the shortfin mako has one of the largest brain-to-body ratios. Isuru Somawardana and his team of shark experts discovered that makos are fast learners, capable of determining if researchers posed a threat. The sharks in the study exhibited unique and never-before-seen behaviors, such as refusing to roll their eyes back during feeding and allowing themselves to be held and briefly touched while being offered bait. The shortfin mako does not rely on electroreception when hunting, unlike the great white shark, based on tests involving fiberglass fish with cables designed to emit weak electrical signals similar to real fish. Instead, they rely on smell, hearing, and primarily vision. The results of this research were presented in a Shark Week documentary in 1999 titled "Mako: Swift, Smart & Deadly."
Conservation
The shortfin mako shark is currently classified as "endangered" by the IUCN, according to the November 2018 update. This species is affected by both sport and commercial fishing and suffers a significant proportion of bycatch in fisheries using drift nets for other species. In June 2018, the New Zealand Department of Conservation classified it as "not threatened," although with a note of "uncertainty about its safety abroad," according to that country's threat classification system.
Classification
- Kingdom: Animalia
- Phylum: Chordata
- Class: Chondrichthyes (cartilaginous fishes)
- Order: Lamniformes
- Family: Lamnidae
- Genus: Isurus
- Species: Isurus oxyrinchus
Habitats and Distribution in the World's Oceans
The shortfin mako shark (Isurus oxyrinchus) is a pelagic species with a very wide global distribution. These sharks are found in tropical and temperate waters of all the world's oceans, from latitudes of approximately 50°N to 50°S.
In the Atlantic, mako sharks are located from the east coast of the United States, including the Gulf of Mexico, to the Caribbean Sea. They are also common in the North Atlantic and can be seen from New England to Florida. In the Pacific, their range includes areas from California to Hawaii, as well as the east coast of Australia and New Zealand waters. They are also present in the Indian Ocean and the Mediterranean Sea.
Mako sharks prefer open ocean habitats, living mainly in the epipelagic zone, which extends up to about 200 meters deep. However, they have also been recorded in mesopelagic waters, at depths of up to 500 meters. Juveniles tend to inhabit waters closer to the coast, while adults are primarily found in more offshore areas, in the deep waters of the open ocean.
The high mobility of mako sharks and their ability to make long migrations allow them to adapt to various habitats and exploit a wide range of food resources in different oceanic regions. These characteristics, along with their ability to maintain a body temperature higher than the surrounding water, provide them with a significant advantage in their hunting and survival activities in the diverse marine habitats they occupy NOAA Fisheries and Oceana.