> How does a snail get its shell?And the answer: It makes its own shell.A group of snails with shells of different sizes and colorsAs a snail grows, itsshell grows too. Snails secrete calcium carbonate through their glands, whichslowly adds layers to their shells. Like a tree, you can roughly determine theage of a snail by the number of layers or rings of its shell.Though snails do not hatch from their eggs fully shelled, these mollusks enterthe world with a protoconch, the first component of a functioning shell.Survival instincts push the young snail to then turn and eat the calcium-richegg from which they just hatched, and thus the snail sets out on the lifelongprocess of ingesting foods with enough calcium to keep their shell on the upwardspiral (pun intended). If you were to slice open a snail shell, you'd notice several main layers in thecross-section. At the surface, there's the periostracum, a thin outer layerusually made with organic material. Below that, you've got a layer of hardcalcium sitting atop a blanket of nacre, a resilient composite material betterknown as "mother of pearl." One aspect that sets snails apart from other shelledcreatures is the lack of blood vessels or nerves in the shell. Unlike turtlesthat fix cracks through cellular repair, calcium and protein secretions fromsnails' mantles can be used to help strengthen the damaged area.Snails are among some of the most highly varied species. Check out this video ofthe deadly Cone Snail below for a taste of these mollusks' variability andevolved specialization.