Deep-sea shrimp coats its shell with aluminium to withstand trench pressure

In the deepest part of the Pacific, the Challenger Deep of the Mariana Trench, scientists have identified a novel survival strategy in the amphipod Hirondellea gigas. Analysis of specimens collected from this hadal zone revealed a thin aluminium coating on the crustacean’s exoskeleton, especially around the tail and leg margins, a feature absent in a comparable shallow-water species from a Japanese bay. The aluminium is not incorporated into the shell structure but forms a removable gel derived from the animal’s metabolism of glucose into gluconic acid, which extracts aluminium from the surrounding sediment.

Laboratory tests demonstrated that shells retaining the coating released far less calcium when subjected to pressures replicating trench conditions, and that the gel also protected salmon roe from pressure-induced protein loss. This marks the first documented natural aluminium exoskeleton in a crustacean, highlighting how life can exploit local chemistry to endure environments once thought uninhabitable.