Animals and Pets pictures

Ads By Google

What are you looking for?
Animals Information
Animals Pictures
Animals Videos
I got here by mistake...

Mako Shark (Isurus oxyrinchus / glaucus)

Mako Shark (Isurus oxyrinchus / glaucus)
Short-fin and long-fin makos are close cousins with the great white shark. They are very fast swimmers and can reach speeds of up to 60 miles per hour. Mako sharks can even leap out of the water. The mako is the quintessential shark. It is probably the most graceful of all sharks, the most beautifully proportioned, the fastest, the most strikingly colored, the most spectacular game fish, and one of the meanest-looking animals on earth.

Like other mackerel sharks, the great white and the porbeagle, the mako has a homocercal (equal-lobed) tail, and a horizontally flattened keel at the tail's base. They all are gracefully streamlined, with a conical snout, dark eyes, small second dorsal fins, and the aforementioned tail shape. The dark eyes give them a look of intense intelligence that they may not possess, as well as the bold look of another group of superbly designed predators, the falcons.

The keels of the mackerel sharks are fascinating and mysterious structures. They show a compression in the dorso-ventral plane of the entire base of the tail, also called the caudal peduncle. It is assumed that this modification is related to speed and power in swimming, since it significantly adds to the musculature of the tail structure, the shark's means of propulsion. Among the sharks, the mackerels show the most pronounced keels, but other species, not normally associated with fast movement, also have this modification. The whale shark and the basking shark, two plankton feeders that are characterized by slow and ponderous movements, have keels on their tail structure, and the tiger shark, not known for speed, also shows this characteristic. Many of the scombroid fishes (tuna, mackerel), and the billfishes (marlin, sailfish), have one or more small keels, but the broadbill swordfish is the only teleost that shows a development that is in any way similar to that of the mackerel sharks. In my paintings of the mako I have tried to show this unique structure by "twisting" the shark, rather than painting it in profile.

Another characteristic that separates the isurids from all other elasmobranchs is their ability to conserve body heat and maintain a body temperature that is considerably higher than the ambient water. It has long been known that certain scombroid fishes, especially tuna, have this ability, but in 1968 two Woods Hole biologists, Carey and Teal, were the first to mention this phenomenon in sharks. Only makos and porbeagles were tested, but white sharks, the third member of the family, were examined, and showed the same structural modifications, so it is safe to assume that they share this ability. According to Carey and Teal, heat is conserved by a "set of countercurrent heat exchangers located in the circulation between the gills and the tissues. The heat exchangers form a thermal barrier which permits the flow of blood but blocks the flow of heat." The authors conclude that there is a threefold increase in the muscle power for every ten degrees Centigrade rise in body temperature. A mako that can jump fifteen to twenty feet in the air requires a starting velocity of 22 miles per hour.

The reproduction and parturition of the mako and the porbeagle are thought to be similar. A pregnant mako has been examined, and it was found to contain ten embryos, five male and five female, ranging in size from 25 inches to 27.5 inches. It can be assumed that these embryos were close to term, since there have been free-swimming makos caught that were 31.5 inches long. According to Bigelow and Schroeder, porbeagles are ovoviviparous (eggs hatch in the female, and are not otherwise attached), and they are nourished in utero by "swallowing unfertilized eggs which lie close to it in the uterus, the result being that the stomach becomes enormously swollen by the masses of yolk so swallowed, forming a so-called 'yolk stomach.' " We can suppose that the same applies to makos.

two mako sharks

Almost all sharks are dark above and lighter below, but few show the dramatic contrast between the rich ultramarine dorsal surface and snowy underbelly of the mako, often separated by a band of silver. A profile portrait of the mako shows this shark to best advantage, emphasizing the conical snout which is so uniquely pointed. This characteristic has resulted in one of its vernacular names, sharpnose mackerel shark. Other common names include blue pointer, mackerel shark, and bonito shark. Makos have particularly long teeth, which are not serrated like those of their infamous cousin, the great white, nor are they cusped like those of their relative, the porbeagle. The teeth of a big mako are huge, resembling curved knives set into the jaw. They are also flattened on the forward surface, which increases this knifelike impression. Smaller specimens have more rounded teeth, so it takes a big mako to display the full and frightening implications of these teeth. Ernest Hemingway had obviously seen big makos, and he describes one in The Old Man and the Sea

The teeth of most sharks are laid back when not in use, and the opening of the mouth brings them into an upright position. This occurs to a limited extent with the mako, but its lower teeth are always erect and serve to give this shark, in life as well as in death, a snaggletoothed and fearful visage. It is the stuff of which nightmares are made. For the big game fisherman, mako fishing is the stuff of which dreams are made. Capable of spectacular gymnastics and at the same time one of the few fish whose actions can be decidedly aggressive, the mako brings an added dimension to game fishing. It is difficult at best to judge heights from the water, but there seems to be a general consensus that a fighting mako can jump at least twenty feet out of the water. Makos charge boats, sometimes jump right into them, and generally provide a level of excitement beyond that of the ordinary game fish experience. In mako fishing, you might lose not only your fish, you might lose your rod or even your arm. It is perhaps the only type of big game fishing where there is a real element of personal danger.

Makos are worldwide in distribution, favoring tropical and temperate waters. They do not school, and they are never seen in very large numbers. Like the porbeagle, the mako tends to inhabit deeper waters than the great white.

One final note about the mako's swimming style, by comparison to blue sharks: Blue sharks are slim, sinuous swimmers, turning and twisting by using their long, curved pectoral fins. By contrast, the mako is a stiff-bodied swimmer, propelling itself through the water with short strokes of its thick, powerful tail. When seeing a mako in its own element, one has the overall impression of blue muscular efficiency.

Rate:  (2.8)

Add To Google Bookmarks Add To Add To digg Add To Yahoo My Web Add To Technorati Add To Stumble Upon Add To blinklist Add To reddit Add To Feed Me Links Add To Newsvine Add To Ma.gnolia Add To RawSugar Add To Squidoo Add To Spurl Add To Netvouz Add To Simpy Add To Co.mments Add To Scuttle

The Book of Sharks by Richard Ellis

Add Feedback

Full Name: *

(The E-mail will not be published)
Title: *

* Required

Related Content