Sharks are a type of fish with a full cartilage skeleton and a highly streamlined body. They breathe through gill slits and have replaceable teeth. They have a strong sense of smell and can detect as little as one part per million of blood in seawater. Some species of sharks can live to be over 100 years old.
Polynesians also considered the shark to be a sacred animal. For them, the shark tattoo served to protect them from their enemies. A Polynesian fisherman would also sport tattoo symbols to protect him and his vessel from sharks in the waters where he fished. In Hawaii, you'll hear about the protective power of the aumakua, a row of tattooed dots around the ankle that keep sharks at bay.
Sharks figure prominently in the Hawaiian mythology. There are stories of shark men who have shark jaws on their back. They could change form between sharks and human at any time they desired. A common theme in the stories was that the shark men would warn beach-goers that sharks were in the waters. The beach-goers would laugh and ignore the warnings and go swimming, subsequently being eaten by the same shark man who warned them not to enter the water. Kamohoali'i is the best known and revered of the shark gods. He was able to take on all human and fish forms. A summit cliff on the crater of Kilauea is considered one of his most sacred spots. At one point, he had a heiau (temple or shrine) dedicated to him on every piece of land that jutted into the ocean on the island of Moloka'i.
A shark tattoo represents power, strength and fearlessness. It's been a long tradition among sailors to have a shark tattoo as proof you are not afraid of death at sea. Sailors also sport shark tattoos for protection.