Deep-sea vent life

Around 79 per cent of the entire biosphere of our planet is made of water that is 1,000 metres deep and there is a place where the ocean reaches its deepest point, at seven miles from the surface. Known as the Mariana Trench, this is a crescent-shaped trough that runs for more than 1,550 miles along the length of the western Pacific ocean. It was first discovered in 1875, by the H.M.S Challenger after sailors dropped a weighted rope about five miles into the ocean. In 1951, the H.M.S Challenger II returned to the same spot and determined that there were two more miles to go before reaching the bottom. In 2012, Titanic director James Cameron descended to the Mariana Trench in a one-man submarine called Deepsea Challenger and spent four hours at a depth of seven miles below the surface, witnessing the deepest waters on Earth. Those midnight black waters are teeming with life around hydrothermal vents. Here are five of the most common vent species:

1. Vent Tube Worm
These bizarre red-and-white worms can be two metres (six feet) tall and have no mouth or stomach. They rely on bacteria living inside them to convert chemicals into food.

2. Pompeii Worm
These bristle-covered worms can survive in hotter conditions than any other animal. They live inside vent chimneys, where it’s over 80 degrees Celsius (176 degrees Fahrenheit)!

3. Vent crab
Adult vent crabs have eyesight similar to military night-vision goggles to help them see at ocean depths of 2.7 kilometres (1.7 miles). They are the top predators around vents.

4. Vent shrimp
These blind invertebrates have simple light detectors on their backs instead of eyes, which may work like infrared heat vision to help them spot glowing vents in the gloom.

5. Scaly-foot gastropod
The metal scales protecting these snails from crab attack are unique – other snails have soft, slimy feet. Their body armour could inspire designs of motorcycles or flak jackets.

For more science and technology articles, pick up the latest copy of How It Works from all good retailers or from our website now. If you have a tablet or smartphone, you can also download the digital version onto your iOS or visit Apple News+. To make sure you never miss an issue of How It Works magazine, subscribe today