Echinoderm
Echinoderm means spiny skin. Even though
echinoderms are called invertebrates,
they do seem to have an internal skeleton
of calcium plates. They also all have a
five part body, a water vascular system
and structures called tube feet.
It includes the starfishes, brittle stars,
sea urchins, sea cucumbers and
sea lilies. All are marine in habitat and
radically symmetrical, a skeleton of
calcium carbonate is often present.
-Pinegreenwoods Montessori
