Posts tagged ‘Shellfish’

How do barnacles get on a ship’s hull?

Barnacles on Ship 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 have 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

What does a walrus use its tusks for?

A walrus is a large seallike animal that lives in the cold North, near the edge of the polar ice.

A walrus can be most easily recognized by its white, daggerlike tusks that never

Walrus

stop growing.  The tusks are really two overgrown teeth that curve downward from the mustached upper tip.

Some walruses have tusks three feet long.

Walruses feed on clams and other shellfish which they rake from the sandy ocean floor with their long tusks.  They crack the shells with their strong back teeth.

The tusks also make good weapons against polar bears enemies of the walrus, or as grappling hooks to help the bulky walrus pull itself over the slippery ice.

Walruses prefer to spend much of their time sunning themselves while drifting about on pack ice.

A thick layer of oily fat, or blubber, beneath its wrinkled skin helps protect the walrus from the freezing cold. – Dick Rogers

 

What are barnacles?

Barnacles

A barnacle is a short salt water shellfish that attaches itself to ship hulls, rocks, docks and other underwater objects.  Anyone who goes to the seashore is likely to see barnacles.

A barnacle hatches from an egg as a tiny, free-swimming creature.  But soon it fastens itself to any convenient object, such as the hull of a ship, pilling, rock, or even a passing whale.

Once attached, a hard, limy shell grows around the barnacle. The barnacles stays for the rest of its life in the place where it settles.  It eats by waving its feathery legs through an opening in the shell to pull tiny sea creatures and plants into its mouth.

The shell has a lid that can be closed in case of danger.

To sailors the barnacle is a trouble.  Masses of them clinging to a ship’s hull reduce the ship’s speed.  The only way to remove barnacles’ shell is to put the ship in dry dock and scrape its bottom.  – Dick Rogers

What is a starfish?

Starfish

A starfish is a star-shaped animal that lives on the bottom of the sea in bays and shallow water.  Starfish eat clams and other shellfish by pulling the shells apart and pushing their stomach into the shells to digest the food.

Starfish have a peculiar way of eating.  The common starfish feeds mostly on shellfish, it especially likes to eat clams, oysters, and mussels.

To open a clam shell, the starfish wraps its arms around it.  Under each arm are rows of tube like feet that stick to the shell like suction cups.  The starfish then pulls the two section of the clam’s shell assist with its powerful arms.

A starfish’s mouth is under its body.  As soon as a starfish has pulled open the clam, it opens its mouth, turns it stomach inside out and pushes it inside the clam’s shell and digests the clam’s soft body.

Once the meat is finished, the starfish pulls back its stomach, leaving only an empty clam shell behind.  Most starfish have five arms, but some have seven arms or more.  If a starfish loose an arm, it can grow another. – Dick Rogers