Weird Fact: Scientists have discovered giant amoebas the size of grapefruit.

Deep below the surface of the Pacific Ocean, inside the mysterious Mariana Trench, something strange is lurking…

They are giant, single celled organisms exceeding 10 cm (4 inches) in diameter – and quite probably the largest living cells on planet Earth.

In July 2011, researchers from the Scripps Institution of Oceanography deployed dropcams into the Mariana Trench, the deepest part of the world’s oceans.

They found the deepest known existence of xenophyophores – single celled organisms found only in deep sea environments. The xenophyophores are huge and abundant, some as large as 20 cm (8 inches) in diameter and with a population density of 2,000 individuals per 100 square meters.

Giant Amoebas

This giant amoeba is 20 cm in diameter

According to Professor Lisa Levin of the Scripps team, “They are fascinating giants that are highly adapted to extreme conditions but at the same time are very fragile and poorly studied.”

Early research on the single celled beasts shows they trap particles from the sea bed, giving them an extraordinarily high resistance to large doses of lead, uranium and mercury. They excrete a slimy substance which covers the ocean floor. They exist in a life of darkness, low temperatures and high pressures.

“The identification of these gigantic cells in one of the deepest marine environments on the planet opens up a whole new habitat for further study of biodiversity, biotechnological potential and extreme environment adaptation,” said Doug Bartlett, the Scripps marine microbiologist who organized the expedition.

And this is just the beginning. The team also found the deepest observed jellyfish to date as well as other mysterious marine animals. They hope to one day capture some of these extreme creatures and study them in high pressure aquariums in the lab.