the Legacy continues…………………….
Gregory R. Mann, Ph.D. {ret.}

Shortfin Mako Shark

“Isurus oxyrinchus”

Shortfin Mako Sharks are truly beautiful animals. The word “Mako” comes from the Māori language meaning either the shark or a shark tooth. It originated in a dialectal variation as it is similar to the common words for shark in a number of Polynesian languages – “makō” in the Kāi Tahu Māori dialect, “mangō” in other Māori dialects, “mago” in Samoan, “ma’o” in Tahitian and “mano” in Hawaiian. They are well-adapted and active pelagic (open water) sharks. Like their cousin the Great White Shark, they keep their body temperature warmer than the surrounding water using a high metabolic rate and efficient heat-exchange system. As the fastest of all sharks, Shortfin Mako Sharks are also known as “Blue Pointers”. They are legendary swimmers reaching sustained speeds of 35 kph (22 mph) with bursts to over 80 kph (50 mph) and have been known to travel over 2,092 kilometers (1,300 miles) in little over a month. These sharks have rapid growth rates with males maturing at around 2 meters while the females mature at about 2.6 meters with maximum lengths of 4 meters and max weights of over 500 kilograms. Shortfin Mako Sharks and their relative the Longfin Mako Shark, represent the largest, fastest and most sophisticated species of pelagic shark on our planet. They are an easily recognizable shark exhibiting all the traits of a Lamnid, they are an extremely robust and streamlined shark with well-developed eyes and an endothermic circulatory system (warm bloodlessness) that is known to maintain elevated muscle temperatures of up to 0.6 °C above the ambient water temperature. Shortfin Makos are heavily built with the trademark strong caudal keels that are a common feature among Lamnids such as Great White, Porbeagle and Salmon Sharks.

Shortfin Mako Sharks have striking coloring with deep purple to indigo dorsal (upper) surfaces, silvery sides, and white ventral (under) surfaces. Only Blue Sharks can rival the Shortfin Mako for beautiful coloration. Shortfin Makos have 5 large gill slits, well-developed eyes and pronounced knife-like, non-serrated teeth. An extremely fast and active shark, they were propelled to “big-game fishing” fame by author Zane Gray who was taken by the animals menacing appearance and volatility during the early part of this century. Author Ernest Hemingway was also impressed by the Shortfin Mako and depicted them as the marlin-marauding monster in his classic novel the “Old Man and the Sea”. Author Richard Ellis also wrote an excellent short story about a deep sea contest between a Shortfin Mako Shark and a Swordfish in his popular work “The Book of Sharks”. Shortfin Makos are found around the world in warm and temperate seas, in the Pacific from Oregon to Chile and juveniles are common in southern California during the summer months. Some scientists believe that females migrate into San Diego’s waters to have their pups. From spring to autumn, pups and 1-2 year-old sharks can be found off San Diego several miles out at sea. Shortfin Mako Shark development is ovoviviparous. Developing young are intra-uteral (within the uterus) cannibals that consume lesser developed siblings. Very little else is known about the reproduction of Shortfin Makos because females abort embryos during capture. Litters of over 8-10 pups are uncommon.

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 centimeters. It is believed that females may rest for 18 months after birth before the next batch of eggs are fertilized. The eggs are retained within the body of the female in a brood chamber where the embryo develops, receiving nourishment from a yolk sac. This is the method of reproduction for the “live-bearing” fishes where pups hatch from egg capsules inside the mother’s uterus and are born soon afterward. Short-finned Makos are prized game fish. Although an oceanic species, their power, aggressiveness, teeth and great speed, make it a danger to humans. Shortfin Mako Sharks have been blamed for a number of both nonfatal & 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. They frequently damage boats and injure fishermen after being hooked. Most attacks occur when a Shortfin Mako Shark is either provoked or caught on the end of a fishing line.