Chrysomallon squamiferum is a gastropod (snail) recently described from deep-sea hydrothermal vents in the Indian Ocean. The characteristic plates on the soft body have earned it the name ‘scaly-foot’, but the most unusual thing about this creature is that the scales are coated in iron sulphide. This is likely produced by endosymbiotic bacteria living in the gut which can process the compound and feed the host snail. However, the precise process behind this amazing ability remains unknown.

Image courtesy of Chong Chen

Endosymbiotic: Living within another animal and bringing it benefits such as nutrition.