Fish Facts » Mako Shark
Description
The shortfin mako body is conic-cylindrical and and extremely hydrodynamic. The snout is bluntly pointed with large black eyes. The caudal keel is prominent and the caudal fin is lunate. The tail has a high aspect ratio (ratio of height to length), which produces maximum thrust with minimum drag and provides almost all of the propulsion for the shark. The anteroventral zone of the snout is black. There are two extant (living) mako sharks, the longfin mako (Isurus paucus) and the shortfin mako (Isurus oxyrinchus). The longfin mako resembles the shortfin mako, but has larger pectoral fins and larger eyes. The presence of only one lateral keel on the tail and the lack of lateral cusps on the teeth distinguish the makos from the closely related porbeagle sharks of the genus Lamna. Color is brilliant metallic blue dorsally and white ventrally. The line of demarcation between blue and white on the body is distinct. The underside of the snout and the area around the mouth are white.The latter is important because is helps differentiate the shortfin from the longfin mako, which has a darkly pigmented mouth region.Color is related to size. Larger specimens tend to possess darker color that extends onto parts of the body that are white in smaller individuals. The juvenile mako differs in that it has a clear blackish stain on the tip of the snout.
Habitat
The shortfin mako is a true pelagic species with a primarily anti-tropical distribution. However, they will enhabit the cooler, deeper water of tropical regions. In some tropical areas where the surface temperature is 27°C (81°F), water temperature may be as low as 59°F (15°C) at depths of 30-60 m (94.2-188.4 ft). With the ability to elevate body temperature, makos are able to maintain themselves in temperatures of 5-11°C (41-52°F). In this sense the makos are somewhat "warm-blooded," meaning that heat in their blood is conserved within the body and not lost through the gills. They have been recorded at depths 740 m. However, shortfin makos prefer water temperatures between 17-20°C. It has been hypothesized this species migrates seasonally to warmer waters. This theory has been supported by tag and release studies. These studies have also shown that while shortfin makos follow warm water, they do so within the confines of a specific geographical area. Consequently, there seems to be limited genetic flow between these geographically distinct populations. Very little is known about the social habits of the shortfin mako, except that it is a solitary shark.
Diet
The shortfin mako is the fastest shark, capable of attaining speeds of up to 32 km/h (20 mph), and leaping skillfully out of the water. The mako holds the speed record for long distance travel: approximately 2130 km (1320 miles) in 37 days for an average of about 58 km (36 miles) per day. The shortfin mako feeds on other fast-moving pelagic fishes such as swordfish, tunas, and other sharks as well as squid. The stomach contents of sharks caught in gillnets off Natal, South Africa, showed a 60 to 40 ratio of shark to bony fish, while a study from the northeastern United States found 77.5 percent of the mako diet was bluefish. Marine mammals and sea turtles are rarely ingested by this species. Despite being a top predator, shortfin makos run the risk of physical harm when hunting prey. There have been many reports of captured sharks bearing scars apparently due to encounters with swordfishes. One mako recovered from a net was impaled through the eye with the bill of the swordfish.
Fishery
Due to its beauty, aggressiveness, and jumping ability, the shortfin mako is considered one of the great gamefishes of the world. Shortfin makos are caught with trolled baits and lures as well as with live or dead baits fished from anchored or drifting boats. Highest recreational catches occur off southern California, the northeastern United States, Australia and New Zealand. The shortfin mako was made famous in Ernest Hemingway's The Old Man and the Sea. Hemingway also caught a 786 pound mako with a rod and reel off Bimini, the Bahamas, in 1963. It is a highly sought after commercial species as well. Its flesh is flavorful and limited quantities may be found in the United States markets, including California where it sometimes is sold as swordfish. Commercial captures are made using longlines, stationary gill nets, and drift nets. The fins and liver oil are also marketed. Shortfin makos are a major by-catch component of the tuna and swordfish fisheries.
Size
Average adult size is 3.2 m (10 ft) and 60-135 kg (135-300 lbs). As with most shark species, females are larger than males and may reach 380 cm (12.5 ft) and weigh 570 kg (1,425 lbs). The largest "mako" taken on hook and line worldwide was 505.76 kg (1115 lbs), however no positive species identification was made (shortfin or longfin mako).
Range
The shortfin mako has a wide distribution. It is found in tropical and temperate waters throughout the world's oceans. In North America it ranges from California to Chile in the Pacific and from the Grand Banks to the hump of Brazil, including the Gulf of Mexico and the Caribbean Sea in the Atlantic. It is commonly seen in offshore waters from Cape Cod to Cape Hatteras. In the eastern Atlantic the shortfin mako ranges from Norway to South Africa, including the Mediterranean and it is found throughout the Indian Ocean from South Africa to Australia. In the western Pacific it ranges from Japan to New Zealand and in the central Pacific it occurs from the Aleutian Islands to the Society Islands.
Source(s)
Florida Museum of Natural History
Source(s) on the web
http://www.flmnh.ufl.edu/fish/Gallery/descript/shortfinmako/shortfinmako.html