In school days, I found often shells of snails stuck to the stems of bushy plants. I thought they are the shells of dead snails. Then, I tried hardly to remove one of them from the plant's stem till it give in. On inspection of its mouth I found a white paper-like structure closing it. I pierced it with a stick to strip it off. To my surprise there was the snail still alive, retracting itself further into the shell! This snail is the Vineyard Snail (Cernuella virgata or Hellicella virgata , 'Natthai' in Tamil).
Its shell is about an inch wide and is white in colour with brown markings. This snail is a land snail living near fresh water sources, and are seen moving mostly at the time of rainy season. As I noted in my school days, they undergo estivation at summer time remaining motionless, and come out in monsoon, when there is an abundance of plant growth all over. They are herbivorous; have microscopic teeth on the radula present in its mouth; they scrape the leaves with them and take up. They have their soft body enclosed in a mantle. This mantle secretes Calcium carbonate and makes the shell grow. The muscular feet is used for the snail's crawling. And the mucus present on it helps in its smooth movement and also prevents its body from drying out. The snail can move even on the sharp edge of a razor blade without being hurt! It has lungs to breathe the air. It is a hermaphrodite having both the sexes in one. After courtship a pair of snails inseminate each other. About 100 eggs are laid in each month! Young ones hatch out in 2 weeks time. This snail has a life span of about 3 years. Its predators are birds, beetles and the leeches. It is attractive to see it move beautifully with its tentacles moving. These tentacles are retractable and bear the snail's eyes.
Such a wonder snail is there in Nature with all its varying colours, forms and sizes - to charm us!
2 comments:
I've a doubt in the shell's growth. How does the small shell expands to a bigger one when the snail grows?
The mantle covering its whole body is also in contact with the inner surface of its shell. As the mantle secretes calcium carbonate and deposits it on the inner shell surface, the shell grows in size.
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