The smallest shark in the world is the Dwarf Lanternshark; a dogfish that lives in the Caribbean Sea. They grow to a maximum of 17 centimeters and eat small fish and shrimp. The next smallest shark in the world is the Pygmy Shark that grows up to 25 centimeters long. These sharks are very closely related. They both like to live in deep water and both have bioluminescence; a chemical reaction in their skin that produces light. Pygmy sharks have been known to hunt in groups making them able to take down large, injured fish.
All sharks have a skeleton made of cartilage and not bone. In addition, they have large, fatty livers that help them to float; oil is lighter than water. Shark skin is rough to touch. Unlike fish, sharks don’t have scales, but rather spiny projections known as denticles. Shark skin is thicker than a human finger and often slimy; sharks secrete a lubricating material that allows them to glide through the water easily. Also, they have a third eye!! This eye is called a pineal eye. It doesn’t see normally, but instead senses daylight. Finally, sharks have a genuine sixth sense; they can sense electrical fields given off by other animals. These sense organs are located on the top of their nose in small depressions in the skin.
Like many of their animal brethren, several species of sharks are endangered. They are hunted the world over for their skin, their meat and their oil. The most tragic deaths result from accidental entrapment in large scale fishing nets looking for tuna and other fish.