There are two types of mako shark: the longfin isurus paucus and the shortfin isurus oxyrinchus. This piece will focus on the shortfin which is much more widespread compared to the longfin, which is primarily found in deep tropical waters.
Appearance: The shortfin mako is a large fish. The females have been known to grow up to 12 1/2 feet in length, while the males tend to be shorter having a maximum length of around nine feet. These are exceptional cases, however; the average is closer to seven or eight feet for an adult. The sharks are, as expected, fairly heavy. On average they weigh around 400 lbs, although the large ones can weigh in excess of 1000lbs. They have five long gill slits, well developed eyes and a conical snout. Their bellies are white and their backs tend to be a dark grey or blue. The mako has a prehistoric ancestor that was very similar in terms of structure, with the key difference being that the Cretaceous Grand Mako was over 20 feet long and weighed over three tons.
Behaviour: The mako is the fastest shark; it is known to reach speeds of 22mph, while some (probably exaggerated) claims give them top speeds of around 60mph. Makos are extremely strong and are estimated by some to be the most powerful sharks when measured pound for pound. Makos, like the Great Whites, have a body temperature far above normal water temperatures. This is achieved through an extraordinary heat exchange system and a high metabolism. This heat exchange system allows the larger makos to swim in cooler seas although the small makos tend to fare better in warm water. Makos are also well known for their extremely high jumps, capable of clearing the water, some have been estimated at twenty feet in the air. These jumps combined with its speed have made the mako a highly prized game fish. The mako primarily thrives on fish, including tuna, swordfish, other sharks and mackerel. The shark has been known to eat dolphins and seals, however they are not a regular part of its diet. The shark is perfectly capable of attacking humans and both injuries and fatalities have been recorded. Commonly injuries are sustained when trying to land a hooked mako. Makos rarely attack unless hooked or provoked. Divers have noted that mako swim in figure eight patterns and approach with mouths open before attacking. Many who fish mako for sport refer to it in a class of its own telling stories of makos who broke free from anglers and came back to attack the boat.
Reproduction: Female makos become sexually mature at a length of eight feet while the males are mature at six. The breeding takes place around the autumn. The mako young mature within the womb in a state of ovoviviparity, meaning that they mature without a placenta. The young engage in oviphagy, the process of cannibalism while still in the womb, feeding on less-developed siblings. The makos develop for 15-18 months before their birth in late winter to early spring. At birth the young are approximately 2 feet long. Litters can be anywhere from 4-18 young although few go above ten. The female makos may then rest for 18 months before the next set of eggs are fertilised. The makos have a very fast growth rate, almost twice that of many similar sharks. It is extremely hard to examine pregnant female makos since they are capable of aborting their pregnancy on capture.
Makos are a remarkable fish, capable of high speeds, mighty jumps and savage attacks. It is not hard to see why they attract so much interest from sport fishers, but unfortunately these fishers combined with the tuna nets and a slow reproductive rate mean that their numbers have been in decline.