Sharks will frequently give warning signals before they attack by pointing their pectoral fins down, raising their heads and arching their backs.
The liver of sharks contain lots of oil, which makes the liver a buoyant organ. This helps keep the shark from sinking.
Blue sharks will keep eating until they vomit and then go back to eating. They eat sea birds, small sharks, mollusks and fish. Squid is one of the blue shark’s favorite foods.