Echinoderms are exclusively found in sea water.

Answer

**Step-by-Step Solution:**

1. **Understanding Echinoderms:**
- Echinoderms belong to the phylum Echinodermata, which is derived from the Greek word meaning "spiny skin." They are characterized by their unique body structure and symmetry.

2. **Habitat of Echinoderms:**
- Echinoderms are exclusively marine organisms, meaning they are found only in saltwater environments. This includes oceans and seas.

3. **Examples of Echinoderms:**
- Common examples of echinoderms include sea stars (starfish), sea cucumbers, sea urchins, sand dollars, and brittle stars. All these organisms inhabit marine environments.

4. **Lack of Freshwater or Terrestrial Echinoderms:**
- To date, no echinoderms have been discovered in freshwater or terrestrial habitats. This reinforces the idea that they are strictly marine.

5. **Conclusion:**
- Based on the information gathered, the statement "Echinoderms are exclusively found in seawater" is true.

**Final Answer:**
- The statement is **True**.

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