How does a clam make its shell?

Shell of a Clam

If you have ever examined a clam shell, you may have wondered how the shell got bigger as the clam grew.  A clam is born with a shell just the right size for its body.  Inside the protecting shell of the living animal is a fleshy layer of tissue called the “mantle.”  

The mantle oozes a limy shell liquid which quickly hardens and becomes part of the shell.  As long as a clam grows, its shell also grows.  The food that a clam eats provides the minerals that form the shell.  The hard shell serves as a clam’s skeleton, and the soft animal inside can never leave it.–Dick Rogers

How does a snail grow its shell?

The shell grows in an ever-widening spiral as the snail continues to add new shell material to its shell during its lifetime.

You have probably seen a common garden snail peeking out of its shell as it slowly creeps along on a slick pathway of ooze.

Where did the snail get its shell?  It was born with a tiny shell just the right size for its body.  The shell serves as a suit of armor to protect the snail’s soft body.

As the snail grows, it oozes a slimy shell liquid that hardens into shell, and so the shell grows with the snail. The snail gets its shell-building materials from its food.

There are many kinds of snails, in almost every part of the world.  Some live only on land, some live in lakes and ponds, and others live deep in the ocean. The most snails are hatched from tiny eggs and look very much like their parents when they are born.

Most snail shells are shaped like coiled spirals.  Some are brightly colored with gray stripes.  Some snails grow shells that are no bigger than a pinhead. But the biggest shells belong to the sea snails called conchs.  Their shell grows to be more than a foot long. - Dick Rogers

How do barnacles get on a ship’s hull?

Barnacles can swim at birth.  When they reach adult stage, they attach themselves to objects in the water and grow a shell.

If you have ever visited a seacoast where there were rocks and piers you’ve almost certainly seen barnacles, for the “crush” you saw on the wharf’s pilings and the rocks was made up of millions of salt water shellfish called barnacles.

When barnacle is first hatched, it resembles a young water flea and can swim about in the water.  But when it reaches adult stage it can no longer swim, so it attaches itself to any convenient object, such as the hull of a ship, piling, rock, whale, or even a sting of seaweed.

Once attached, a hard lime-like shell  forms around the barnacles. The barnacle eats by waving its feathery legs through an opening in the shell to pull tiny sea creatures and plants into its mouth.

In olden days, sailor of wooden sailing ships had to periodically pull their ships ashore to scrape off the masses of barnacles clinging to the hulls, because they reduced the ship’s speed and made steering difficult.  Today, special paints, prevent growth of barnacles.-Dick Rogers

How does a snail grow its shell?

Snail

The shell grows in an ever-widening spiral as the snail continues to add new shell material to its shell during its lifetime.  

You have probably seen a common garden snail peeking out of its shell as it slowly creeps along on a slick pathway of ooze.  Where did the snail get its shell?  It was born with a tiny shell just the right size for its body.  

The shell serves as a suit of armor to protect the snail’s soft body.  As the snail grows, it oozes a slimy shell liquid that hardens into shell, and so the shell grows with the snail.  The snail gets its shell-building materials from its food.

There are many kinds of snails, in almost every part of the world.  Some live only on land, some live in lakes and ponds, and others live deep in the ocean.  The most snails are hatched from tiny eggs and look very much like their parents when they are born.

Most snail shells are shaped like coiled spirals.  Some are brightly colored with gray stripes.  Some snails grow shells that are no bigger than a pinhead.  But the biggest shells belong to the sea snails called conchs.  Their shell grows to be more than a foot long.-Dick Rogers