Description & Behavior: The shortfin mako shark, Isurus oxyrinchus (Rafinesque, 1810), aka mako, shortfin, short-finned mako, blue pointer, mackerel shark, blue dynamite, bonito, spriglio, paloma—is a truly beautiful animal. It is a well-adapted and active pelagic shark. Like its cousin, the great white, it keeps its body temperature warmer than the surrounding water temperature using a high metabolic rate and heat-exchange system. It has a remarkable swim speed reaching sustained speeds of 35 kph (with bursts over 80 kph) and has been known to travel over 2,092 km in little over a month. These sharks have a rapid growth rate, twice as fast as some of the other Lamnidae species. Males mature at around 2 m while females mature at about 2.6 m. A maximum length of 4 m long and max weight over 505.8 kg has been recorded.
There are two types of mako, the most common and widely spread is the shortfin mako, Isurus oxyrinchus, and the less common and more specialized longfin mako (or big-eye mako), Isurus paucus. Makos represent the largest, fastest most sophisticated species of pelagic shark on the planet.
An ancient relative Isurus hastilus is nearly identical in terms of tooth structure and function. The ancient mako hastilus was probably 6 m long and nearly 2,800 kg; it was the Cretaceous grand mako that shared the seas with kronosaurs, ichthyosaurs, and plesiosaurs.
The mako sharks are an easily recognizable shark exhibiting all the traits of a Lamnid, they are an extremely robust and streamlined pelagic shark with well developed eyes (larger in the longfin) and an endothermic circulatory system (warm bloodedness) that is known to maintain elevated muscle temperatures of up to .6°C above the ambient water temperature. Makos are heavily built with the trademark strong caudal keels that are a common feature among Lamnids such as great whites, porbeagles and salmon sharks.
Longfin makos are apparently a more deep water tropics-dwelling predator of which little is known. It wasn’t even described as a separate species until 1966.
Makos have striking coloring with deep purple to indigo dorsal surfaces, silvery sides, and white ventral surfaces. The longfin mako has a shaded coloration around the mouth and underside of the snout, unlike the shortfin mako which is snow white around the mouth and under-snout. Only the blue shark can rival the makos for beautiful coloration.
Mako sharks have five large gill slits, well-developed eyes (slightly larger in the longfin) and pronounced knife-like, non-serrated teeth. An extremely fast and active shark, it was 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.
Illustration: © Diane Rome Peebles