Invertebrates
Scaly-foot Snail
Chrysomallon squamiferum · also called sea pangolin
Armoured in scale-like plates reinforced with iron sulfide, a scaly-foot snail survives entirely on bacteria housed inside its own body, clinging to a scattering of hydrothermal vent sites in the Indian Ocean now threatened by growing interest in deep-sea mining.
Overview
The scaly-foot snail, Chrysomallon squamiferum, is an armoured gastropod native to hydrothermal vent habitat recorded at a small number of sites in the Indian Ocean. Its unique iron-sulfide-reinforced armour, complete reliance on internal chemosynthetic bacteria for food, and Endangered status tied directly to its extremely limited range make it one of the most remarkable and vulnerable invertebrates found anywhere in the ocean.
Armour unlike any other animal’s
No other known animal builds its skeleton the way the scaly-foot snail does, reinforcing the scale-like plates on its foot with iron sulfide, a mineral more commonly associated with the chemistry of the hydrothermal vents the snail depends on for survival.
Status
Endangered, with its entire known population confined to a handful of hydrothermal vent sites in the Indian Ocean now facing direct threat from deep-sea mineral mining interest.
Scaly-foot Snail: common questions
What makes the scaly-foot snail's armour so unusual?
This species is the only known animal to incorporate iron sulfide into its skeleton, using it to armour the scale-like plates covering the sides of its muscular foot, a mineral not used this way by any other known animal.
How does the scaly-foot snail get its food?
This species houses chemosynthetic bacteria within a greatly enlarged internal gland, and these bacteria provide essentially all of the snail's nutrition, converting vent chemicals into usable energy in exchange for a stable home.
Why is the scaly-foot snail considered Endangered?
This species is known to survive at only a small number of hydrothermal vent fields in the Indian Ocean, and deep-sea mineral mining interest in those same sites poses a direct threat to essentially the species' entire known population.
Why is the scaly-foot snail nicknamed the sea pangolin?
This species is sometimes given this nickname because its overlapping, scale-covered foot resembles the armour of the pangolin, a scaled mammal found on land, even though the two animals are entirely unrelated.