Do Snails Have Hairs?

Snails are fascinating creatures that captivate us with their distinctive spiral-shaped shells and slow-paced movement. While snails are well known for their smooth, slimy appearance, the idea of snails having hairs is not commonly heard of. This article aims to shed light on the truth behind snails, exploring the question "Do snails have hairs?" So,

Do snails have hairs?

While it may not sound true, some species of snails bear hair-like structures on their shells that reach varying densities and lengths.

Now, this brings us to the question:

What family, genera, or species of snails have hairy shells?

Hairy shells are observed in several species of the families:

Polygyridae
Helicidae
Hygromidae

They are also observed in some species of the genus Endothyrella.

Below are some examples of snail species that bear hair-like structures.

Trochulus hispidus

Trochulus villosus

Ashfordia granulata

Isognomostoma Isognomostomos

Suteria ide

Stenotrema florida

Where do these hairs originate from?

The hairs on a snail's shell arise from the periostracum. The periostracum is a thin layer composed of conchiolin (a protein secreted by mollusks) and surrounds the calcareous shells of the snails.

Why do certain species of snails have hairy shells?

The hairy shells are almost exclusively found in snails that live in moist or humid microhabitats such as layers of fallen leaves, broad-leaved vegetation, damp meadows, or wet scree.

According to a study, it was hypothesized that the snails found in wet microhabitats experience a greater surface tension while moving. Therefore, the hydrophobic (water-repelling) hairs on the shells aid in locomotion and facilitate movement in wet environments by relieving the surface tension.

Then, a relatively new study made a completely opposite conclusion. The researchers analyzed snails in the genus Trochulus and their data showed that the hairs increased the adherence of the shells to wet surfaces. This was evident from the fact that hairy shells required a higher minimum force to overcome adhesion than smooth shells on a water-covered leaf surface.