About All Sharks Essay, Research Paper

About All Sharks

BY. SHAUN LEVY

SHARK FAMILIES: There are more then 350 know species of sharks today, which can

all be placed under 8 scientific orders that contain 30 families. They are

placed into these categories by their shared characteristics, this is called

taxonomy. The more closeley related species are placed in another family in the

order.

SQUAINIFORMES: The angel shark as they are commonly known are

characterized by their RAY like flattened bodies. This order has one family

which is called SQUATINDAE that contains about 13 species. The maximum size

that can be attained by any one of these species is 4-6 feet in length.

PRISTIOPHORIFORMES: These shark are known as the saw shark. This order has only

has one family

PHISTOPHORIFORMES which contains five species. These sharks are

easy to recongnize due to the fact that they posses an ellongated blade like

snout that is lined with sharp teeth along the edges, thus, the name saw sharks.

SQUALIFORMES: The order possesses three family which consist of about 82 species.

These sharks are characterized by their slender, cylinder-shaped bodies, long

snouts with shortened mouths.

HEXANCHIFORMES: The Hexanchiformes or cow sharks, comprise of two families.

Recognized by their six or seven pairs of gill slits, there sharks can often

be found in deep water. The frilled shark (CHLAMYDISELACHUS ANGUINEUS)

who’s appearance is quite unmistakable due to it’s “eel” like appearance, is

perhaps one the strangest shark that exist today.

FOSSIL RECORD: Shark fossil record is fargmentery at best. Most fossils found

so far consist of nothing but teeth in some cases a few vertebra have been

found. This is rare due to the fact that sharks have bones instead, they have

cartiladge which countrary common belief is rather solid. In the rarest of

cases complete fossil have been discovered. Scientific data shows that

following a period of great physiological changes. There was not to many

changes in the sharks fossil in the millions of years, of studying the shark

fossils. The Hybodonts who made their appearance some 320 million (years ago the

age of the dinosaurs) where quite common through out both oceanic and fresh

water. Due to reasons unknown to science both oceanic and fresh water hybodonts

because exticnt at about the same time as the dinosaurs. The largest shark to

ever swim the oceans is called the megalodon. Many think that it’s ancestor to

the great white shark however there is great controversy surrounding this

matter. The size of the shark is 40 to 50 feet in length it is safe to say that

megalodon is still considered to be largest predatory fish to have ever existed.

THE PERFACT PREDATOR: The shark is considered by many to be the perfect

predator. It’s perhaps the most perfectly adapted predator in it’s environment.

The shark jaws another facinating development of evolution. Each species jaws

are perfectly adapted to that sharks eating habits some sharks have long pointed

teeth for cathing fish others have teeth contains the most of the species of

sharks are harmless botton dwellers, like catsharks or houndsharks. However the

most of those sharks are in danger of be coming extinct.

THE SHAPE OF SHARKS:

The sharks has all different kinds of shapes and sizes or sharks one can find in

the ocean. Sharks posse a richness of diversity and body forms, ranging from

the popular sharks. A good example of this is a Bizzare Goblin Shark. This

sharks has a horn-like protrusion coming from it’s head. The body forms of

sharks can be related to their way of life. Some like the angel and wobbegong

sharks the shape of these sharks of these sharks is perfectly adapted to their

environment and their way of life. All sharks swim by snaking their way

through the water while using their pectoral fins for lift and direction.

Shark attacks:

Most attacks take place within 100 feet of the shoreline. However, it’s not

impossible to be stuck on open sea. Sharks have been recorded following boats

for many years. Sailors used to consider this a bad omen and would throw one

man overboard to please the shark. If there is one drop of blood from a person

a shark and sense 200 feet where the blood is coming from. The people most at

risk of shark attacks are men from a shipwreck just floating in the open ocean.

This is because there are usually large amounts of blood in the water. The most

know shipwrecks that involved with sharks in the U.S.S. More then 500 people

died by shark attacks. The most common shark that attacks is the blue shark.

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