How Tiny Crustaceans Survive the Crushing Pressures of the Mariana Trench

A submersible dubbed Jiaolong in the Mariana Trench on June 27, 2012, in the western Pacific Ocean.

(Image credit: VCG/VCG via Getty Images)

As if preparing for battle, some shrimplike creatures suit up in aluminum armor to survive the ravages of the deepest part of the oceans, a new study finds.

Amphipods are little crustaceans found in most waters on Earth. One species, Hirondellea gigas, dwells at the bottom of the sea — the Challenger Deep in the Mariana Trench, some 35,797 feet (10,911 meters) down.

In the extreme pressures of the deep sea, the calcium carbonate that makes up the shells of amphipods and many other marine animals reacts more readily with carbon dioxide to dissolve more easily in water — essentially leaving their soft bodies naked and vulnerable. As such, amphipods typically are not found below about 16,400 feet (5,000 m), which made H. gigas' presence in the Challenger Deep a mystery. [Photos: The Freakiest-Looking Fish]

The scientists found that the H. gigas exoskeleton contained aluminum on its surface. But how did the little creature find this metal, since it's sparse in seawater? The researchers discovered that the crustacean uses sugar-based chemicals in its guts to extract aluminum ions from the seafloor mud that it swallows as it feeds on plant debris raining down from the surface. It generates these sugar-based molecules from sugars it gathers from this plant debris.

Charles Q. Choi is a contributing writer for Live Science and Space.com. He covers all things human origins and astronomy as well as physics, animals and general science topics. Charles has a Master of Arts degree from the University of Missouri-Columbia, School of Journalism and a Bachelor of Arts degree from the University of South Florida. Charles has visited every continent on Earth, drinking rancid yak butter tea in Lhasa, snorkeling with sea lions in the Galapagos and even climbing an iceberg in Antarctica.