Question

The characteristic feature of echinoderms is the possession of??

Answer 1

Characterstic's of echinoderm-
1) Radial symmetry
2) Tube feet
3) Regeneration capacity( Losing any arm they can regenerate the same) 

Answer 2

echinoderms are exclusively marine, they can regenerate missing limbs arms, they possess radial symmetry, they are protected through their spiny skin, spines