The Earth is more water than land, which makes sense that we still have so much to uncover in the depths of our oceans. Today we accept that the dark seas are teeming with all sorts of strange and alien-like creatures, many of which are still waiting to be discovered. But this notion wasn't always so popular.
Many biologists in the 19th century believed that life underneath such cold, watery depths was simply not possible due to the lack of light and the extreme pressure. This idea was known as the Azoic theory, to mean "lifeless." It was championed by Edward Forbes, who thought that sea life ceased to exist at below 300 fathoms, which is about a third of a mile.
Of course, life exists much deeper than what Forbes originally thought. In fact, at 11,000 meters below sea level - one of the most seemingly inhospitable places on earth - sea life still finds a way. Watch the video to learn the creatures that inhabit these corners and their unique adaptations. Bonus: some creatures are so new to us that they don't even have proper scientific names yet!