What makes a snail's shell special, is the fact, that it is asymmetrically coiled to one direction, either left or right. Compared to a Nautilus's symmetrical shell, looking the same from left or right, the whorls of a snail's shell mount to a clearly visible tip - the apex - on one side of the animal.

Do snails have coiled shells?

The spiral shells of snails are often used as a textbook example of biological structures that possess chirality. Shell-coiling is important because a snail's sexual organs are usually twisted and it is difficult for snails of opposite handedness to reproduce.

Do snails make spirals?

A snail's slimy organs and parts follow suit, developing with a twist that echoes the asymmetrical shell — a fact that inspired a team of researchers to identify that trait's source. According to a study published Tuesday in Development, this fundamental spiral is all down to one gene.