Imagine living in the sea where it is permanently dark, cold, and food is hard to find. For many animals at depth, it may be weeks to months between meals. If you find something to eat, you have to hang on to it. This is why so many deep-sea fishes have lots of big teeth. This dragonfish, spotted off the coast of Australia, even has teeth on its tongue. They would be terrifying animals ... if they weren’t the size of a banana. (Photo by Julian Finn/Museum Victoria)

Volunteer rescuers prepare to drag a beached humpback calf to sea at Surfers Paradise Beach on August 8, 2011 on the Gold Coast, Australia. The humpback calf was stranded on the beach yesterday for hours before volunteer rescuers were able to drag it back to the sea. SeaWorld Australia says a mother and calf humpback were sighted near where the calf was released and are hoping to get photos to verify it is the same calf and that it has been reunited with it's mother. (Photo by 2011 SeaWorld Australia via Getty Images)

Tourists standing near the sea shore are hit by a wave, which surged past a barrier under the influence of Typhoon Chan-hom, in Qingdao, Shandong province, China, July 12, 2015. One of the most powerful typhoons to strike eastern China in decades disrupted air, rail and sea transport on Saturday after forcing the evacuation of more than a million people from the provinces of Zhejiang and Jiangsu, state media reported. (Photo by Reuters/Stringer)

A man driving a vintage car reacts as he passes by crabs crossing a highway on their way to spawn in the sea in Playa Giron, Cuba on April 25, 2017. Each year, after the first spring rains, millions of red, yellow and black landcrabs march for days from the surrounding forests to the bay on Cuba's southern coast to spawn in the sea. (Photo by Alexandre Meneghini/Reuters)

Sea lion “Jay” paints a Chinese character reading “the Serpent” at the Hakkeijima Sea Paradise aquarium in Yokohama, suburban Tokyo on January 3, 2013. The event, marking the forthcoming Chinese lunar calender year of the snake was held as part of a New Year's attraction. (Photo by Kazuhiro Nogi/AFP Photo)

St Andrews University students skinny dip in the sea as May Day celebrations in St Andrews, Scotland on April 30, 2017. Hundreds of revellers ditched their clothes and bravely jumped into the bitterly cold North Sea. (Photo by Alamy Stock Photos)

Ground personnel work next to the Soyuz TMA-13M capsule of the International Space Station (ISS) crew of Alexander Gerst of Germany, Maxim Suraev of Russia and Reid Wiseman of the U.S. after its landing near the town of Arkalyk in northern Kazakhstan November 10, 2014. A veteran Russian cosmonaut and two International Space Station crewmates, one from the United States and one from Germany, returned safely to Earth on Sunday with a parachute landing of their Soyuz capsule in Kazakhstan, ending 5-1/2 months in orbit. (Photo by Shamil Zhumatov/Reuters)

Mosha, the elephant that was injured by a landmine, has her prosthetic leg attached at the Friends of the Asian Elephant Foundation in Lampang, Thailand, June 29, 2016. Mosha was 7 months old when she stepped on a land mine near Thailand’s border with Myanmar and lost a front leg. That was a decade ago... (Photo by Athit Perawongmetha/Reuters)