A predator is any animal that kills other animals for food. The most powerful predators are flesh eaters, e.g; sharks and
lions. Animals that prey on their own species are called cannibals.
Sharks are wonderful animals that have been around since as long as the dinosaurs existed: They inhabit in waters all
over the world, in every sea, and even in some lakes and tributaries.
Sharks, a general name applied to all the larger Elasmobranch fishes of the sub-order Selachoidei, the smaller members
of this sub-order being called dog-fish. Most sharks are placed into a Superorder called Selachoidei. This Super Order
covers many Orders (and Family) of sharks.
There are around 453 unique species of sharks that can be divided into 34 different families. These families are all very
special in the way they live, eat, and appear.
Sharks have an elongated and very flexible body, terminating in a powerful tail and having extraodinary swimming
powers,from the point of view both of speed and of endurance.
All sharks have different sizes, shapes, teeth, teeth, fins, habitat, diet, personality, method of reproduction, and other
Some species of shark are very rare—great white shark--and others might be common--dogfish shark. This group also
includes shakes and stingrays.
Have no bones
Unlike the bony kind of fish, sharks are boneless: Their skeleton is made of only cartilage, which is a very strong, fibrous
material but not nearly as hard as bone. Also unlike bony fish Sharks also have no gal bladder. . Some parts of their
skeleton—their spine--are full of calcium. Although, most sharks do not chew their food, but gulp it down whole it in large
Many sharks have up to 3000 teeth in their entire jaw. Their teeth are arranged in rows. If one tooth is damaged or lost, it
often substituted by another. Most sharks can have around five rows of teeth at a single time. Although they may have
many rows of teeth, the front set of teeth is the largest and does most of the chewing.
There are many different types of sharks that can range in size from as big as a human's hand to bigger than a minivan.
Adult sharks can grow to a size from seven inches long--Spine Pygmy shark-- up fifteen meters in length--the Whale
Although there are some exceptions, generally sharks are medium in size, and are about the same length as humans;
around five to seven feet tall. The fact is half of the three hundred sixty eight, shark species are actually less than
one meter in length.
Sharks come in many different types of body shapes. Generally, sharks have a streamlined, torpedo-shaped body that
can easily glide through the water. Although, some bottom-dwelling sharks—angel sharks-- have flattened bodies that
allow them to hide in the sand of the ocean bed. Even some sharks have an elongated body shapes--cookie cutter sharks.
For instance, the Saw sharks have extra long snouts, thrasher sharks have a extraordinary elongated upper tail fin, which
they use to paralyze prey, and hammerheads have extraordinarily wide heads. And finally, the Goblin shark has a giant,
pointed spike on its head, making it seem like a goblin.
Where sharks live
Most sharks reside in relatively warm waters; like the bull sharks, tiger sharks and hammer-head shark. The minority of
sharks, such as the mako, thresher, basking and blue shark, live in temperate water, which is neither very cold nor hot.
Many other sharks, including the Greenland, Globin and dogfish shark, inhabit in even cooler waters! Some sharks stay
in the same region their entire lives while others will migrate across oceans in search of breeding grounds.
Images: The Great White Shark. Photos taken at Gansbay, South Africa.
South Africa, more specifically Cape Town, is without a shadow of a doubt, one of the best destinations worldwide for
experiencing sharks, especially Great White sharks, at close proximity.
A closer look at some shark orders, families and species
There are at least 453 species of sharks belonging to 8 orders and 34 Families.
To the family carcharinidae belong sharks which have two dorsal fins and a nictitating membrane. There are in fact 48
species of carcharinidae including the tiger shark, Dusky shark, Bull shark, Galapagos shark, Sandbar shark and many
others.The tiger-shark (Galeocerdo cuvier ) is one of the commonest and handsomest sharks in the Indian Ocean.
The ground colour is a brownish-yellow, ornamented with black or brown transverse bands or rounded spots.
While shark species such as the bull shark, the tiger shark and the great white shark are well-known species, they still
have their own characteristics. For example, the great white shark has a grey and white skin, his teeth are triangular and
serrated and its snout longer and wider than the blue shark. The bull shark is known for his wide rounded snout. The bull
shark has stripes, a short snout and hooked shaped teeth.
You can find bull sharks off the Atlantic coast of the U.S., from Massachusetts (rare) to the Gulf of Mexico. Off the pacific
coast southern California (rare) to the Gulf of California. They are most common around the Florida coastline.
Their habitat is primarily shallow coastal waters, lagoons, bays, and river mouths. The really scary part is Bull sharks can
also be found in fresh water that connects to salt water and have been caught in the Mississippi river as far upstream as
As for the smooth hammerhead shark ( family Sphyrnidae - 9 species), well its name says it all as the shape of his
head appears to be similar to a hammer and its eyes are located on the side of each tip, which explains the different
type of vision compared to its cousins.
From the family Lamnidae ( belonging to the Order Lamniformes - 15 shark species, placed into 7 families ) come
5 species; the porbeagle (Lamna nasus), white shark (Carcharodon carcharias), shortfin mako, longfin mako and salmon
shark - the white, shortfin mako and porbeagle, are found in our New England waters.
The porbeagle is a stout shark that is blue-gray on top and white underneath with a white patch on the trailing edge of the
first dorsal fin. They are not dangerous to man. All Lamnidae family sharks have cold solid black eyes.
To the small family Rhinodontidae ( belonging to the order Orectolobiformes - 31 species placed into 7 families) belongs
the single species known as Rhinodon typicus ( Whale shark). It's found in the Indian Ocean and perhaps also in the
Pacific. The whale shark has a front-set mouth with a very short snout and is covered with a distinctive pattern of spots.
In the Family Hexanchidae (Order Hexanchiformes - Sixgill, Sevengill and Frilled Sharks ) the single dorsal fin is placed
very far back and the gill-slits may be six or seven in number in place of the usual five. To this family belong a number of
small sharks of which the Bluntnose sixgill shark (Hexanchus griseus) occurs in the Atlantic and the Mediterranean.
Another shark belonging to this family is the Cow shark (Hexanchus griseus).
The family Squalidae (Belonging to the Order Squaliformes - Dogfish Sharks) comprises small sharks with sharp-
pointed cuspidate teeth, arranged in numerous series. Includes the British dog fishes.
The two British species, the lesser (small-spotted dog-fish or rough hound - canicula) and the larger spotted dogfish
(large-spotted or nurse hound - catulus), belong to the most common fishes of the coast and are often confounded with
each other. They are also known as ground-sharks.
While smaller than its cousins, the lesser spotted dogfish, with a maximum length of 1 m and weight of 3 kg; its
differences are not limited to this. First of all, the shape of his eyes resembles the shape of a cat’s eyes contrary to the
more beady and circular one of its cousins. Also, its spotted skin has a velvety look and reminds you of leopard fur. Its
fins are also larger and more flexible similar to angelfish fins. And finally, its jaws do not look as dangerous as a great
white shark’s teeth as they are way smaller and can be compared to a kitten’s teeth.
The spiny or picked dog-fishes ( Acanthias) and some larger forms of which the most important is Lamargus Borealis,
the Greenland shark which occasional strays to British waters.
The spiny or piked dogfish (Acanthias) inhabits the temperate seas of both the N. and S. hemispheres. The spiny
dogfish are of a greyish colour, with some whitish spots in young specimens, and attain to a length of 2 or 3 ft . They are
viviparous, the young being produced throughout the summer months.
The black-mouthed dogfish (Pristiurus melanostomus) is rarely caught on the British coasts.
The Cestracion Philippi ( the Port Jackson Shark) - small form, flattened and pavement like teeth being used to crush
the molluses upon which they chiefly feed - belongs to the family Cestraciontidae. Both the dorsal fins have a spine in
The fox-shark or thresher (Alopecias vulpes), of which every year specimens are captured on the British coast. It is
common in the N. and S. hemispheres.
The basking shark (Selache maxima), sometimes erroneously called "sunfish," is the largest fish of the N. Atlantic.
It is well-known for swimming with his large wide open to collect food particles such as plankton.
Then you have one of the smallest sharks around, the spined pygmy shark, which has a maximum length of 20 cm.
Its mouth which looks similar a leech is nonetheless voracious on preys. One of its peculiar physical characteristic is that
it creates its own light and uses its bioluminescence to attract its preys or mates. Another difference is the absence of a
You have the nurse shark which has golden eyes that almost make you believe that it suffers from blindness. It also looks
similar to a catfish with what looks like whiskers. Its long caudal fin, which is the top part of its tail and its strong pectoral
fins are more flexible than some of its cousins.
The Pacific angel shark is often confused with rays as it shares the same type of shape. It has no dorsal fin, its skin
has a velvety look and his pectoral fins are large and flexible. Finally, the six gill saw shark is probably one of the most
unique types of sharks with its saw like snout with two touch-sensitive barbells.