Shark -

: The Portuguese dogfish has been found at depths of over 12,000 feet , where the pressure is immense and the water is near freezing. Guardians of the Ocean

: The largest fish on the planet, these gentle giants filter-feed on tiny plankton and can dive deep into nutrient-rich cold water to regulate their temperature. Key Posting Tips : The Portuguese dogfish has been found at

: These slow-moving giants can live for over 400 years , meaning some sharks alive today were swimming when the Pilgrims arrived in America. : Use high-contrast imagery of a shark's silhouette

: Use high-contrast imagery of a shark's silhouette or a close-up of their eye to emphasize their prehistoric nature. : The Portuguese dogfish has been found at

Sharks are not "villains"—they are the immune system of the ocean.

: Using organs called the Ampullae of Lorenzini , sharks can detect the tiny electrical impulses of a heartbeat in the dark or under sand.