9. Octopus and Starfish

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An octopus is a mollusk that has no shell at all

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It looks as if it is all head and arms

An octopus has eight (8) arms, called tentacles, which have many

suckers on them

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Suckers hold on tightly to objects they touch

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The suckers help an octopus to crawl and to hold on to its food

An octopus moves by pulling itself along by its tentacles

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It can also use a kind of jet propulsion to move

It pulls in water through its gills and sends it out very fast through a

tube under its head

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The force of the water moves the octopus backward

One way that an octopus can find food is by hiding among stones and

seashells on the ocean floor

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The octopus can change its color to match its surroundings

Small water animals that swim by usually do not see the octopus

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The octopus can grab an animal with its tentacles

Most kinds of octopuses are as small as a person’s fist

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How do they escape bigger animals that feed on them?

An octopus can squirt out a liquid, like ink, that blackens the water

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The octopus then swims away

Giant octopuses that live in the Pacific Ocean have few enemies to

swim away from

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These octopuses can grow to be 30 feet long

Starfish live in all oceans

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Fish is part of their name, but they are not fish but invertebrates

Starfish have a small central body, with a mouth on the bottom side

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Most starfish have five arms that stick out from their bodies

Other kinds have more than 25 arms

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Stiff spines cover their bodies and arms

Starfish are often dull yellow or orange but can be bright colors, too

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They can be as small as ½ inch and as big as 3 feet wide

Starfish use their tube feet to move

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These small tube feet are under each arm

Suction cups are attached to the feet

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Suction cups help starfish to move

Starfish eat animals, especially like clams and other mollusks

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A starfish catches a clam with its arms

The clam closes its shell to protect itself

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Using its tube feet, the starfish forces the shell open a little bit

Then the starfish turns its stomach inside out and pushes it out of its mouth

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It sticks its stomach into the opened clamshell and eats the soft clam body

Then the starfish pulls its stomach out of the clam

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and puts it back into its own body

A starfish can grow new arms if its arms are broken off

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This is called regeneration

In fact, if a starfish loses all its arms but one and most of its central body

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a new body and new arms will grow

Starfish eat mollusks like clams and oysters that are valuable crops for

fishermen

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The fishermen may try to destroy starfish by cutting them into pieces

But the pieces grow into even more starfish!

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