Biggest
Carnivorous Fish...
GREAT WHITE SHARK Carcharodon
carcharias
Solitary
Leviathans
Great white sharks are still a mystery, as scientists
are still trying to unravel the lifestyle of these denizens of the deep.
They are solitary creatures roaming the ocean in constant search of
food. Scientists are still unsure how to tell the age of a great white
shark or how long they live, how often and where they breed, and how
quickly they grow.
It is widely
held among shark experts that the great whites take a long time to reach
the fearsome proportions of record and that over fishing of these incredible
creatures has led to a rapid decline in their numbers. No one knows
how long it would take for the world's great white shark numbers to
rebound if we were to completely halt fishing of this species. We are
now beginning to realize the important role they play in their ecosystem,
eliminating the weak and the sick from their environment and keeping
seal and sea lion numbers in check. Lack of great white sharks to control
the sea lion population may be one of the contributing factors to the
declining salmon populations along the coast of California and Oregon.
What scientists
have been able to study in great whites is their predatory and feeding
behavior. In the Farallon Islands, off the coast of California, scientists
are videotaping and documenting attacks on pinnipeds (seals and
sea lions - the sharks' favorite prey) to understand how these awesome
killing machines operate. By studying shark attack behavior, scientists
hope to understand and predict how and when a great white will attack.
People who "use" the ocean can use this information to protect themselves
from being attacked by a great white shark.
Expert Killing Machines
The teeth of the great white are perfectly
designed for slashing flesh and mortally wounding prey with
a minimum of effort. If a tooth is lost during an attack, another
quickly grows forward to replace it.
Great white
sharks have a number of adaptations (behaviors and anatomical features)
that make them such efficient killers:
For sensing
- specialized sensory organs called
ampullae of Lorenzini
located in the shark's snout, which can
detect electrical currents of as little as .005 millivolts that are
generated by every living creature in the water
Extremely
acute and sensitive sense of smell,
allowing the great white to detect the most miniscule amounts of blood
in the water up to 5km away - blood means injured victim = less effort
required for the meal (Efficiency!)
For stalking
- the coloring of the great white makes for excellent camouflage in
the ocean - dark above, and light below makes it difficult to be detected
while swimming on the bottom (great whites strike from below)
For striking
- a large, powerful body and specially designed tail that provides
for enormous bursts of energy for striking with such tremendous strength
that the first bite is frequently a death blow
Several rows
of razor sharp teeth
that are continually replaced to ensure an entire jaw of efficient,
lacerating implements
Scientists who
study the Great White Shark have found that when attacking their prey,
the strategy of the great white is usually to strike from below in one
powerful blow (some human shark attack victims have likened the experience
to being hit by a car), inflicting a lethal bite to head or trunk of
its victim. The shark then swims away a short distance to let its victim
bleed to death so that it will not have to struggle with its meal. This
brief respite after the initial chomping is what allows many human victims
(but not all) to escape being eaten alive by the great white predator.
Other Great Sharks
The largest
great white on record measured 21 feet long. Some claim a 23 footer
was caught in the Mediterranean, but that report has not been authenticated.
Since great whites are such elusive and mysterious creatures, it's entirely
possible there may be even bigger ones out there we have yet to meet.
Paleontologists
have found the fossilized jaws of an ancient ocean predator that is
an ancestor of the great white, called Charcharodon
megalodon. The
size of the jaws indicate the size of the creature may have been as
large as 50 feet long! Some scientists argue that it's possible these
monsters still exist in the ocean deeps, that we just haven't found
them yet.
There are other
large species of living sharks that have reputations for ferocity that
rival the great white. The bull shark, white tip reef sharks, blue sharks,
tiger sharks, seven gill sharks, and some monsters of the deep that
can get up to 20 feet long - sleeper sharks and primitive six gill sharks.
These species of sharks may rival the ferocity of the great white, but
none of them have been found to grow as large. Carcharodon carcharias
holds the world record for largest carnivorous fish,
but there are even bigger ocean predators
than the Great White roaming the ocean...
Location: They are found
in temperature waters in oceans throughout the world, lurking
near just about every coastline except the polar regions. They
especially like to hang out in the East Pacific Ocean, off the
coast of California where enormous populations of sea lions gather.
Facts: These guys can get
to be the size of a family car - over 2 tons and up to 21 feet
long! The world record Great White Shark was caught in 1948 and
was 21 feet long, but the average length of an adult is 12-16
feet.
The Scientists Who Study this Cool
Stuff?
Marine Biologists, Ichthyologists.