What are some body shapes of sharks?
THE BODY OF A SHARK IS SHAPED LIKE A TORPEDO FOR FAST MOVEMENTS
Most sharks are ectothermic, but some (namely the Great White) can produce their own body heat. They do this by using the heat produced by burning energy from pumping their blood. As blood is pumped to the body, the blood moving back to the heart gives off its heat which is picked up by the cold blood. In this way, some sharks can be warmblooded, but most are ectothermic.
Many sharks, including sand tiger sharks and great white sharks, keep their eggs inside their body until the baby sharks hatch, but some sharks, such as dogfish, lay strange-looking eggs which attach on to water plants or the sea floor instead. Some people call them a mermaids purse and they are sometimes found washed up on beaches.