Mako Shark

Usually, the Shortfin Mako shark is biologically known as Isurus Oxyrinchus. They are also called blue pointer (blue Mako shark) or bonito shark. They belong to the genus Isurus and the family named Lamnidae. They are the mackerel sharks of order lamniform and class Chordata. The longfin Mako sharks are generally referred to as Marko sharks. The Shortfin Mako shark is about 4 meters long and is 13 feet in length. They are the endangered species as marked by IUCN.

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Description of Mako Shark

The shortfin mako shark is a large species even larger than the longfin mako shark. As compared to the other members who belong to the Lamlid family, the shortfin mako shark has an average length of 3.2 meters which is 10 feet tall and has an average weight of 60-135 kgs. They show sexual dimorphism where the females are comparatively larger than their male counterparts. The mature females are usually larger in size and exceed a length of 3.8 meters and weigh 570 kgs. The first biggest mako shark was caught in September of 1973 on the coast of the Mediterranean in France which was 4.45 in length. On 3rd June 2013, the largest Mako shark that was caught on hook and line was 600 kgs. The giant mako shark that is known till now as a specimen was caught off the coast of Italy and was then weighed in the Italian fish market that came around 1000kg and the length was 4 meters. The longest species of Mako shark was caught in Turkey at the coast of Marmaris that measured a length between 5.77 to 6.19 meters. 

Grander mako which is popularly known as the shortfin mako shark possesses a cylindrical shape. It also possesses a tail that is long and elongated. They display a countershading where they portray a brilliant metallic blue on the dorsal area and white ventral. The line demarcating the metallic blue and white border is quite prominent. There is a presence of white coverage around the mouth and the snout area. As the specimen starts growing in their age the coloration starts appearing to be darker shades on most parts of the body which is comparatively whiter in small young specimens. With the help of a blackish stain that appears on the tip of the snout, most of the fishermen and fish experts differentiate the juvenile from the adults where the stain is missing. The appearance of the longfin mako shark is very similar to that of the shortfin mako shark except that the former has longer dorsal fins, large eyes and the coloration around the mouth and the snout is darker while in later it is more fader. With the absence of lateral cusps on the teeth and the presence of only one lateral keel on the tail, the mako sharks can be differentiated from their close resemblance with porbeagle sharks of the genus Lama.

Range and Habitat

Range

Usually the offshore temperate and tropical sea around the world makes a comfortable habitat from the mako sharks. But the longfin mako sharks are often seen in the more offshore waters and in the gulf stream. Thus they can mostly be seen in the marines of New Zealand. The mako sharks are considered as the pelagic species as they are mostly found dwelling in the upper layer of the sea waters and can reach a maximum depth of 150 meters from the surface of the earth. They normally inhabit far away from the land, though they very occasionally visit the islands of the water, rarely visit the shores or come closer to the islands. As they are one of the very few warm-blooded that is alternatively termed as endothermic shark species, thus they are normally not found in the waters with a temperature lower than 16 degrees celsius. 

Habitat

It has an elaborative stretch of habitat where they are usually observed residing in the Western Atlantic starting from Argentina and the Gulf of Mexico to the brown banks that are off the Nova Scotia coast. In the seas of Canada, this particular species of shark is neither very abundant nor very rare in the population. Swordfish, also known as broadbills in some countries, are a very good source to indicate the presence of shortfin mako sharks as they are the prime food source and therefore the ideal prey from the shortfin mako sharks and the former also prefer similar water conditions to Inhabitat. Unlike the longfin mako sharks, shortfin mako sharks are usually seen traveling a greater distance looking for their prey or mates. For instance, a female shortfin mako shark that was tagged off from the shores of California was found by researchers in the central Pacific region where a Japanese research vessel was also present. Thus it was observed that the female mako shark has traveled a distance of 2776 km. Similarly, another specimen was caught off who traveled over 2128 km within a span of 37 days which means the specimen was traveling at a speed of 58km per day. 

Feeding Habits of Mako Shark

The shortfin sharks are often seen feeding upon the species of the class Cephalopoda like squids, octopus, cuttlefish, nautilus, etc or on the bony fishes like tuna, mackerels, bonitos or swordfish. Sometimes they also prey on other small sharks, sea turtles, porpoises and sea birds. The mako sharks like every other shark species have a tendency to swim beneath the prey so that they can have a clear vision of them and can attack swiftly from beneath even before the prey is alert. They usually lunge in a vertical position tearing off the fins and flanks of the prey into small chunks.in Ganzziri and Isola Lipari costs of Sicily, the shortfin mako sharks are seen attacking brutally resulting in the amputation of gills of swordfish imparting their heads and gills. Thus causing serious injuries to the fish and the tendency of the mako sharks to seriously kill them. In addition to this, they showcase the typical nature of a predator as they prefer to hunt down the swordfish in late spring and early summer timings as it is the favorable spawning season of swordfish and they are most vulnerable during this season.

The shortfin mako sharks are observed to intake 3% of their total body weight and then it takes 1.5 to 2 days to digest the average-sized prey. As compared to another inactive species of shark named sandbar shark which consumes only 0.6% volume of meal to their total body weight and takes about 4-5 days to digest the same, the former is much faster. A study was conducted on 399 males and females mako sharks to analyze their stomachs for information about their eating patterns. Under this study, it has been observed that both male and female mako sharks stretching from Cape Hatteras till Grand bank prefer to prey on bluefish. Their total diet consists of a sum total of 77.5% volume of bluefish. The stomach capacity of both male and female mako sharks is just 10% of their total body weight. More specifically, the study shows that the shortfin mako sharks stretching from Cape Hatteras to Grand bank consume only 4% to 14.5% of the total bluefish available in the sea. 

The shortfin mako sharks that have an average length of 3 meters usually have wider and flatter teeth that are situated in the interior of their mouth as compared to the smaller mako sharks. These teeth actually enable them to pray swiftly on big specimens like dolphins, swordfish, bluefish and other small sharks. The mako sharks are known for their strongest bite that was recorded in the year 2020 in New Zealand.   

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Reproduction and Lifespan

Reproduction 

The mako sharks usually exhibit a viviparous reproduction system as they are yolk-sac-bearing specimens giving birth to the young one. During the 15 to 18 months of gestation period of an adult female mako shark, the developing embryos feed on the unfertilized eggs for their nutrition within the uterus. Unlike sand tiger sharks, they do not engage themselves in sibling canalization. Usually, 4 to 18 young are born at a time from the late winter to the early spring season. Each baby mako shark is about 70cm in length. The females usually take a break of 18 months as their resting period before they again engage themselves in mating. The shortfin mako sharks bear their young once every 3 years. 

Lifespan

Like most of the other shark species, the mako sharks also indicate their age by the sectioning of the vertebrate which is among the few bony structures the body of a shark generally possesses. Another way of assessing their age is by counting the growth bands of the mako shark. Until the year 2006, there was a huge misconception that the shortfin mako sharks grow two growth bands in their vertebrate per year and thus their maturity, longevity as well as sexual maturity was miscalculated and was underestimated. But a later landmark study proved it as a misconception and established that the shortfin mako sharks grow only one growth band a year. This study has incorporated 258 shortfin mako species and it was published that the male shortfin mako shark lives up to 29 years. 32 years is the maximum age limit of females shortfin mako sharks. 50% of the total shortfin male mako sharks attain sexual maturity at the age of 8 whereas 50% of the total shortfin female mako sharks attain sexual maturity at the age of 18.

Behavior

The shortfin mako is the fastest shark of all the shark species that are known to humankind. The fastest shark can even take a leap in the air while it is hooked. Thus they make one of the high-sought-after games of fish in the world. In some of the cases, it also has been reported that the shortfin sharks have jumped into the boat after they are being hooked. Many of the studies even elaborated that the mako sharks have a large brain as compared to their body ratio.

Conservation status

They are currently marked as endangered by IUCN. They were listed as vulnerable in the year 2019 as a follow up of being marked as being-threatened in the year 2007. They are often targeted for fishing sports by the commercial as well as sport fisheries. Sometimes they are also drifted into the fishing net set for other species and thus there has been a report of a large proportion of bycatch of this particular species. The department of conservation in New Zealand has classified it as “not threatened” in their coastal region with marking as “uncertain whether secured overseas' ' as per the New Zealand threat classification system.