+Echinoderms are a phylum of exclusively marine [invertebrates](/wiki/invertebrate), known for their often five-fold [radial symmetry](/wiki/radial_symmetry). These ocean dwellers exhibit a unique water vascular system and typically possess a calcified exoskeleton, giving rise to their characteristic spiny skin.
+## See also
+- [Starfish](/wiki/starfish)
+- [Sea Urchin](/wiki/sea_urchin)
+- [Marine Life](/wiki/marine_life)
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