All animal which is living around us has common skin attribute like all have scale which is sensitive to environment. They acquire skin with different thickness with different amount of hair according to environment condition. Animals which live in the hottest places have less amount of hair or no hair and animal with colder region have thicker skin with excess hair. Sea animal have totally different characteristics and they have skin which is suitable for living in water. Some species have shell but the shell is not stronger than iron.
But how you react if I present a snail which has a shell made of Iron sulfide, In other words a snail builds a shell out of iron. Foot of the shell which protrudes out of the shell is covered with iron plates. And it’s all thanks to bacteria, which is building the armor for snail.
This is not usual snail and lives in exceptional environment of Indian Ocean. It lives in hydrothermal vent of Indian ocean which is 2,400 meters to 2,800 meters deep. This species found in 2001 at theKairei hydrothermal vent which is located on the Central Indian Ridge and also found in Southwest Indian Ridge.The size of scaly-foot gastropod is 10.4 inch to 1.8 inch.
Where temperature of magma coming out from earth crust is 750 degrees F . Water near these hydrothermal vent have temperature between 60 to 464 °C .This is very harsh and toxic condition for living. The strange thing about this snail is there are two variety one is black and other is white live in same condition with same predators but white snail lacks the iron.
But it is assumed that white snail don’t have bacteria that black snail possess. Bacteria that lives inside Scaly-foot gastropod responsible for chemosynthesis. The process by which they produce food in the absence of sunlight with the help of neighborhood chemicals. This snail has no digestive system and have a gland which is bigger than other snails. In this gland bacteria lives and produce food for snail with chemosynthesis.
But the real reason is not known yet why iron is required to snail for living in such harsh condition?