| A | B |
|---|
| Echinodermata | have spiny skin, tube feet, and 5-part radial symmetry |
| tube feet | suction cup-like structures used for movement. |
| endoskeleton | often made up of hardened calcium carbonate |
| water vascular system | consists of an internal network of fluid-filled canals connected to the tube feet. |
| madreporite | sieve-like structure the water vascular system opens through. |
| starfish | flip their stomachs out through their mouths |
| respiration | gas exchange through tube feet or skin gills |
| brittle stars | excrete waste through the mouth |
| radial nerves | connect the nerve ring with the body sections |
| nerve ring | response system that surrounds the mouth |
| statocysts | organs used for balance |
| arms | reproductive organs are found in these |
| feces | form in which solid wastes are excreted |
| sea lilies | most ancient form of echinoderm |
| ammonia | excrete nitrogenous waste in this form |
| Chordata | some echinoderms are remarkably similar to this phylum |
| anterior or posterior end | adult echinoderms have neither |
| detritus | sea cucumbers feed on this |
| hydraulic pumps | water vascular system operates like this |
| filter feeders | sea lilies, basket stars, and some brittle stars feed this way |
