There are around 358 unique species of sharks that can be divided into thirty different families. These families are all very special in the way they live, eat, and appear. All sharks have different sizes, shapes, teeth, teeth, fins, habitat, diet, personality, method of reproduction, and other attributes. Some species of shark are very rare?great white shark--and others might be common--dogfish shark. All sharks belong to the domain of cartilaginous fish?Elasmobranches. This group also includes shakes and stingrays. Sharks are also one type of fish that have no bones--only cartilage. 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 pieces, 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.



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. 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 shark. 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.

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.