ECHINODERMS

Echinoderms are spiny-skinned invertebrates that

live in the water.

Examples of Echinoderms

Sea-star/Star FishSea-star/Star FishSea urchinSea urchinSand dollarSand dollarSea cucumberSea cucumber

Echinoderms move around using tube feet. They are hollow

structures with suckers on the end. Water is pumped into the tube feet and the feet extend. Water is sucked back into the

body and feet contract. As the tube feet extend and contract, the echinoderm moves ahead.

STARFISH TUBE FEET

Let’s talk about Sea-Stars

a.k.a. Star Fish

STAR FISH – they are also called sea stars. They have five

“arms” and look somewhat like a pointed star. Others have

many arms and are called “sun stars”.

STARFISH – CROWN OF THORNS

PATRICK!!

Wouldn’t his camouflage work better on the rock?!?

Starfish can regenerate new arms when the old ones are broken off. Even if a starfish is cut in two, each of the pieces will regenerate into a new animal. Most live for about

three to five years.

Close up of a starfish’s spines.

DOUGHBOY STARFISH

SUNFLOWER STARFISH

This starfish is hanging onto the side with its tube

feet.

BRITTLESTAR

What is a Sea Urchin?

SEA URCHIN – the sea urchin is shaped like a ball and is covered in long, moveable spines. They are called scavengers because they feed on

decaying matter.

SEA URCHIN with other invertebrates along for a ride!

Sea urchin spines and tube feet.

Have you seen a Sand Dollar

before?

SAND DOLLAR – The sand dollar lives slightly buried in the sand. It eats tiny bits of animals and plants found in the sand grains. The food travels along the grooves on the underside of the sand dollar’s body to its mouth.

SAND DOLLARS

The sand dollar has a thin, flat, circular body. It looks like a silver dollar or a cookie. The body of the sand dollar has many slots. The top surface has a set of breathing tubes that are arranged in the form of a five-point star. The sand dollar’s body is covered with tiny movable spines which are used for crawling and digging.

http://www.youtube.com/

watch?v=cFFCwQ1-

pIw&feature=related

Don’t forget about

Sea cucumbers!!!

Sea Cucumbers are unusual Echinoderms-their supporting spines are microscopic and under their skin. They are cylindrical in shape.

See the tube feet?!?

Sea cucumbers

come in many

sizes and colors.

One last sea cucumber!

A REALLY COOL FACT…

The starfish can push its stomach

out through its mouth!!!

Many starfish feed on shelled animals such as mussels, clams, and oysters. When it feeds on an

oyster, it attaches its tube feet to the two halves of the oyster’s shell and pulls the shell halves apart to make a

tiny crack. Then the starfish pushes its stomach into the crack. The stomach surrounds the oyster’s soft body, slowly digests it, and absorbs the food into its

body.

Isn’t that amazing?!!!

THE END!

By: Julie Hunt and Marta Howard ~ Degan Elementary