These have a skeleton of spongin

Includes jellyfish, coral and anemones

These have two tissue layers with primitive nerves but no brain.

First bilateral animals

Has 3 tissue layers and a primitive brain.

Includes earthworms and leeches

Bilateral organisms with well developed digestive systems that are one-way.

Includes snails, nudibranchs, clams, squid and octopus.

Many have a hard mouth part known as a beak or radula.

Their name is from the Greek for "spiny skin"

These are radially symmetrical and only found in the ocean.

These have no blood and eye spots on their "arms"

Larvae are planktonic with bilateral symmetry while adults are benthic with radial symmetry

Sea stars pull their prey apart and then extrude their ________ to eat the organism.

Most sea stars have 5 rays so they are said to be

Echinoderms are closely related to

Echinoderms have an open cavity surrounding the digestive system known as a

The opening in a sea star that allows water into the water vascular system

The side of the sea star that has the mouth is called the