Phylum Echinodermata

___ are spiny-skinned marine invertebrates that are easily distinguished from other animals because of their peculiar body forms

came from the Greek word “____,” which means spiny, and “___,” which means skin

Echinoderms have rigid calcareous plates called ___ that is covered by a thin epidermis

A characteristic unique to this phylum is the _____ , a network of hydraulic canals that branch into extensions called ____ (podia) for locomotion and feeding.

five classes under Phylum Echinodermata

Species in this class are star-shaped with arms that are indistinct from a central disc

includes brittle stars and basket stars, they have a distinct central disc and long, flexible arms.

are more or less globular or disc-shaped with no arm

This class differs from other echinoderm classes by being attached to a hard surface (sessile) by a stalk a part of their lives like sea lilies

They are called “odd” because of their cucumber-shaped bodies that are elongated on the oral-aboral axis, thus their English name