10. Crabs and Lobster

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Crabs belong to a group of water animals called crustaceans

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Vocabulary:

crustaceans

An invertebrate water animal with a shell

They also have segmented bodies

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Vocabulary:

Segmented bodies

A body made of separate parts that are joined together

Most crabs have five (5) pairs of jointed legs

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A jointed leg has several separate parts joined together

Four pairs of legs are used for walking on rocks and on land

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Although crabs can move in any direction, they usually move

sideways

The fifth and back pair of legs are used for swimming

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These legs are often flat like paddles

The two front legs have claws.

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Crabs use their claws for catching food and for fighting enemies

As a crab grows, it molts

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Vocabulary:

molts

To shed, or get rid of, a shell and to grow a new one

At the time a crab molts, it can also grow a new leg or class if it has lost one

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In fact, if some enemy is holding on to a crab’s leg, the crab can separate

itself from the leg

Then when the crab molts again, it grows a brand-new leg!

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There are many different kinds of crabs.

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Most crabs live in oceans, but some live in fresh water

The hermit crab can be a marine species or a land species

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Hermit crabs “borrow” shells from other organisms

Video of Hermit Crab changing

shells

The pea crab is so tiny that it lives inside the shell of an oyster

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The giant spider crab of Japan has legs that are 4 feet long

The horseshoe crab lives in the shallow ocean waters with the

seahorse

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Crabs eat other small crustaceans and plant life

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In turn, crabs are eaten by many vertebrate animals, like people!

Lobsters belong to the crustacean group of animals

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Lobsters are found only in salt water

The segmented body of a lobster is divided into 21 segments

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A lobster has 5 pairs of jointed legs

Four pairs of legs are used for crawling along the ocean bottom

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The other two legs end in large claws, one slightly bigger than the other

Migration of the lobster

A lobster uses its claws to catch and tear apart small fish and mollusks

that it eats

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Like crabs, lobsters molt

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Lobsters can also grow a new leg if one breaks off

A lobster’s eyes are on stems that stick out from its head

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A lobster cannot move its head, but it can move the stems

A lobster has 20 pairs of gills

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With its gills, the lobster gets the oxygen it needs from the water

The American lobster is dark green on top and orange or blue underneath

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This is the kind of lobster that many Americans eat

At one time, so many lobsters were being caught that they became

endangered

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Today, laws protect lobsters

25March of the Lobster