The long lifespan of the Greenland shark, shown here in the cold, deep waters of the Uummannaq Fjord, may only be surpassed by that of the ocean quahog, a clam known to live as long as 507 years.
Marine ecologist Neil Hammerschlag says he can sometimes identify sharks like Emma (pictured) by the way they move. "It's pretty cool to be able to jump in the water and say, 'Hey look, there's Emma the tiger shark!' "
A frilled shark swims in a tank after being found by a fisherman off Japan's coast in 2007. One of the rare creatures was recently caught in Australia, shocking fishermen.
Awashima Marine Park/Getty Images
John Hernandez of Kailua, Hawaii, who owns John's Fresh Fish, is shown on Thursday. In the background at right is a container ship owned by Matson Navigation Co. A pipe maintained by the company cracked and caused the molasses spill.