Shortfin Mako Shark Essay, Research Paper
The shortfin mako shark is the fastest fish in the world. It is
capable of attaining speeds of up to 60 mph. It s dark red iron-rich
muscles on the side of the shark s body and especially on the tail
enable the shark to swim at these speeds. The speed of the mako
affects its physical characteristics, its eating habits, and its predators.
The average size of the shortfin mako shark is from 10 to 12 feet
and the largest size ever recorded was 18 feet. This fish weighs about
1,000 pounds. Its large heavy conico-cylindrical shaped body is
colored in such a way that it blends into the openwater environment
making them invisible to prey. Its back is a deep blue gray and its
underparts are snow white. The snout of this shark is bluntly pointed;
this helps the shark to speed through the water. Its first dorsal fin,
which is short starts behind the pectoral fins. This is unusual
compared to other sharks in the mako shark s family. The anal fin is
tiny compared to the dorsal fin. The mako has long gill slits and
strong caudal keels. The upper and lower lobes of the caudal fin are
of almost equal length. The mako has large eyes and is considered
one of the most beautiful common sharks.
The mako shark is found worldwide in temperate and tropical
seas. It is found from the Gulf of Maine to the equator and is most
densely populated in the Gulf of Mexico. These sharks are pelagic,
yet they are occasionally found inshore. They migrate seasonally
about 1,550 miles. In the summertime, mako sharks stay relatively
close to the shore, about 20 miles out. In the winter they migrate into
substantially deeper waters. They do this so that they can be in water
warmed by the gulf stream.
The Isurus oxyrinchus has a two year reproduction cycle.
Though few have been seen mating, scientists believe that the male
makos attack the females and force them to mate. They believe this
because often times females are found with horrible injuries to the
dorsal and pectoral fins following mating. Gestation takes about 12
months and reproduction is ovoviviparous. This means that the
mother carries the eggs internally until they are ready to hatch. While
in the womb the embryos are oviphagous (they feed on unfertilized
eggs). An average litter consists of 10 to 12 pups, each being about
two feet long.
The shortfin mako shark is a carnivorous animal that feeds on
swordfish, tuna, mackerel, tunny, herring, tarpon, and other large fish.
Once a 120 pound swordfish was found whole, sword and all, in the
stomach of a 730 pound mako. Often times these sharks swallow
their prey whole. The long, thin, sharp teeth of the mako enable it to
catch its agile prey. They are smooth edged and grow in rows. The
first two rows are used for obtaining prey, and the other multiple rows
are used to replace damaged of lost teeth. The amazing speed of this
fish also helps it to catch its food.
The mako shark s only enemy is man. This fish is hunted for
sport and used in products such as the oriental delicacy, shark fin
soup, and cartilage pills. The mako shark is a big game fish because
of its speed, size and the great fight it puts up when hooked. It can
leap 15 feet out of the water to free itself from the fisherman. Mako
sharks are dangerous and have attacked many humans and small
water crafts. Fisherman must be careful. Because the shark is
hunted so much and so often, some people worry about it becoming
endangered. There have been no collective studies on the mortality
or population dynamics of the mako shark, and no one knows how
many sharks there are in the world. Though the mako shark has no
conservation status at this time, the National Marine Fisheries Service
(NMFS) currently manages this shark. The NMFS has reduced
catches of the shark by commercial fishermen.
It seems all animals have there place in the ecosystem,
including the much feared mako shark. If sport fishing continues and
the shark s population dwindles, the disastrous effects would be felt
for all; even man, which at times believes he is above nature and not a
part of nature.