Whether you find snails slimy, slippery or fascinating, you may have not paid much attention to these slow-moving critters yet. That soft, featureless blob with wiggling antennae and a shell on its back does make sense to us only when it munches on our favorite flower plants. There are 43,000 snail species living in the sea, in freshwater or on land. In Sri Lanka, they account 246 species, out of them 83 percent are endemic to Sri Lanka.
Living quiet lives under the shadows of trees, land snails are quite mysterious, hiding themselves under their shells. A snail’s most discernible feature is its shell. It protects the snail from desiccation and certain predators. It also helps it to hold in moisture. Though it reduces speed of its movements on land they constantly lug around their heavy ‘home.’ Shells come in different sizes, shapes, colors and patterning.
They vary, too, by the number and shade of color bands, number of whorls, height and width. Usually shells are colored in various shades of white, brown green or black to hide better in their environment. The shell is mainly made out of Calcium, so they try to get a diet which contains lots of calcium to keep their shells thick and healthy.
The snail moves by creeping on a flat, using a large, muscular ‘foot’ located underneath the body. The band of very maneuverable muscles in the foot contract and expand to create a kind of rippling movement, so that it pushes the snail forward.
If you wonder about their speed of mobility, it’s all relative to their body size and related factors. The world’s fastest land snail is called European Brown Garden Snail. It travels about 6 or 7 inches per minute on a flat smooth surface. Snails leave slimy trails behind them as they move on. This slime protects them from injuries and facilitates their movements by reducing the friction of the surface.
Senses and food
Although snails are quite delicate, they live pretty much anywhere. But they do not prefer hot and dry conditions and some hibernate during dry seasons. They retreat into its shell and seal the opening in dry weather to protect their body from drying up. Snails are mostly active at nights and become much more active on rainy days.
A snail’s tentacles which look like antennas are extremely important. Eye spots are located the tips of these slender tentacles. The tentacles contain smelling sensors and they feel what the simple eye spots may not see.Snails can move their tentacles back – forth and up – down ways to obtain a better view.
The majorities of the snails are herbivorous and graze on plants fungi and algae, while hardly ever some are omnivorous, eating both plant and animal matter. Their mouths are located underneath so they eat by gliding over a plant or other food surface.Snails have a type of teeth called a ‘Radula’ in its mouth for grinding up the food they take in.
This radula is like a rough serrated tongue, like electric chain saw with rows of tiny teeth which it uses to scrap off plants and fungi to eat. A typical Snail can live up to 5 to 10 years. So, next time when you walk around your garden mind your steps not to crush them to an early death, by avoid stepping on their ‘mobile homes’.Corilla colletti
A Sri Lankan forest snail
Pic by: Santhushya Hewapathiranage