On hydrothermal vents deep beneath the Indian Ocean lurks a scaly-footed gastropod. While this minute deep-sea snail might seem unassuming, it actually has a special ability: it incorporates metal into its body, forming a hard protective armor around its fleshy, exposed foot.
It is the only animal known to science that can to do this.
Discovered living on the bases of black smokers at the Kairei hydrothermal vent field in 2001, scaly-foot gastropods reside only on hydrothermal vents in the Indian Ocean.
These scaly-foot gastropods (Chrysomallon squamiferum, also known as scaly-foot snails, sea pangolins, or volcano snails) are found at depths between 1.5 miles (2,400 meters) and 1.7 miles (2,800 meters).
The snail’s metal armor is composed of iron sulphides greigite and pyrite, and effectively act as a “second shell”. The armor is composed of three layers that strengthen the snail’s defenses as well as dissipate heat.
This helps defend the snail from predators that stalk the vents — such as deep sea crabs — and regulate the snail’s body temperature in the extreme heat of its hydrothermal vent environment.
In the video below, you can see several scaly-footed gastropods congregating around black smokers in the Longqi Vent Field, 1.7 miles (2800 meters) beneath the southwest Indian Ocean.