Echinoderms are spiny skinned invertebrates that live in saltwater. They include sea stars, brittle stars, sand dollars, sea urchins, and sea cucumbers.
The skin of most echinoderms is stretched out over an internal skelton (endoskeleton) made of hardened plates. The animal's body has a bumpy texture.
Science Activity 1
- Display samples of echinoderms. Have each child use a magnifying lens to observe these interesting animals.
- Younger students can trace the invertebrates and color their pictures.
- Older students can sketch the invertebrates and try to include as much detail as possible in their sketches.
- Then students can describe (oral or written) a particular echinoderm using as many adjectives as possible.
- Students can also compare and contrast 2 or more echinoderms.
Science Activity 2
- sea star, if available
- magnifying glass, if available
- water dropper
- Use a magnifying glass to observe a sea star.
- Explain to students that we will now do an activity to demonstate how a sea star moves and clings to surfaces.
- Add a little water to a dropper.
- Squeeze out all the water except for a little (the last drop).
- Now squeeze the last droplet of water onto the inside of your arm. Then, while squeezing touch the tip of the dropper into the water droplet and touch the tip of the dropper against your skin. Then release the bulb.
- Hold the dropper by the tube and slowly lift the dropper. Observe closely.
- What did you observe happen to your skin?
To learn more about Echinoderms, here are some good books that students might enjoy reading.