Monday, July 6, 2015

Shortfin Mako Sharks



                                                             







The Shortfin Mako Shark
           Isurus oxyrinchus                                                        

The shortfin mako is the worlds fastest shark, clocked at speeds of over 30 mph! They're a powerful species that are known to breach when hunting and when caught by fishermen.



Identification:
Shortfin makos are sleek sharks with very powerful tails. Their dorsal side is a bright metallic blue or purple, with silvery sides that fade to white on the ventral side. They have pointed snout with a U-shaped mouth and dark black eyes.
Mako sharks have long gill slits
The mako shark has strong and large keels on the caudal peduncle that allow them to swim at great speeds. Their caudal fins are the same size on the top and bottom, which allows them to speed through the water.





Classification:
Kingdom : Animalia
Phylum : Chordata
Subphylum : Vertebrata
Class : Chondrichthyes
Subclass :  Elasmobranchii
Superorder : Selachimorpha
Order : Lamniformes
Family : Lamnidae
Genus : Isurus
Species : oxyrinchus


Similar Species and Other Family Members:
There is another species of mako shark, the Longfin Mako Shark (Isurus paucus). The longfin mako is similar in appearance to the shortfin mako, only it has longer pectoral fins and larger eyes.
Isurus paucus


Reproduction:
Mako sharks are viviparous, meaning they give livebirth like humans do. A typical litter of mako shark pups is about 10-18 pups, but litters can range from 4-25 pups. Mako sharks exhibit oophagy, which is where the developing shark pups eat the unfertilized eggs in the womb.


Size:
Male shortfin makos mature at around 195 cm (6.3 ft), while females mature at around 270 cm (8.8 ft). The largest shortfin makos can reach up to 400 cm (approx. 13 ft)


Diet: 
Mako sharks eat mainly fish such as bluefish and swordfish. They will also eat other open water sharks like blue sharks. They have even been known to eat marine mammals, including dolphins, porpoises, and seals. Recent studies have found that mako sharks will breach when going after prey, just like white sharks do.


Teeth & Jaws:

Mako sharks have pointy teeth that are perfect for stabbing into slippery fish. 


Fun Fact! - The teeth of the white shark on the infamous Jaws poster are actually mako shark teeth, as white shark teeth weren't thought to be "intimidating" enough!


Habitat and Distribution:
Mako sharks are mainly pelagic species that live in open water all around the world. While they spend more time in pelagic waters, they do occasionally travel into coastal waters. They're found in temperate and tropical waters worldwide.


Conservation Status:
The shortfin mako is listed as vulnerable on the IUCN Red List of Threatened Species. They are often caught as bycatch by commercial fishermen, and are fished for their fins like most sharks. One of the largest threats to mako sharks is overfishing by recreational fishermen.



sources:
The Sharks of North America, Jose I. Castro
http://www.iucnredlist.org/details/39341/0
Sharks of the World, David A. Ebert, Sarah Fowler and Leonard Compagno 
note: none of the images are mine