em a more streamlined affect in the in water. Yet, some types of sharks, the ocean dwellers have a flat body similar to that of skates and rays. Sharks can travel with great bursts of speed especially when attacking their prey or when excited. The fastest-swimming sharks have a moon-shaped tail that provides extra power and durability for swimming. Sharks don't have a swim bladder. This is what helps regulate depth control. Sharks do not have this organ. Yet, they do have a oil organ that also acts as a gas bladder. This oil is less dense than water and acts as a gas bladder. A shark has multiple rows of teeth. The mouth of sharks is in the front of the head. In some species, sharks teeth are replaced as much as once a week. Some sharks have teeth used to crush and grind. These are some what like what humans have. They also have sharp teeth. These can be compared to incisors that humans have. These types of teeth are very important to sharks because they are carnivores and depend on their teeth in order to eat their prey. A sharks body in covered by scales which cover their bodies. These scales make the skin of a shark very rough and strong. Sharks have a very different breathing system than most animals that live in or on this earth. Sharks also receive oxygen from the water through gills, yet, unlike fish, sharks do not have a gill cover. This makes a sharks breathing system very unique. Instead of a gill cover, sharks have from five to seven slits in the skin on each side of the head. Water passes through of these slits after the shark's gills remove the oxygen. Most sharks cannot pump water over their gills, as do the majority of fish. Sharks have special senses that allow them to compete for prey. They have excellent hearing, yet, can not hear many low pitched sounds. Sharks can find their prey the sounds that they make. Some scientists believe that the shark's lateral line through out their back bone detects the lowest-pitch...
