Vocabulary Vocabulary ReviewReviewCh 38 – Ch 38 –

Echinoderms and Echinoderms and Invertebrate Invertebrate ChordatesChordates

A radially symmetrical marine

invertebrate that has an

endoskeleton, such as a starfish, a sea

urchin, or a sea cucumber

Echinoderm

One of the small, calcium carbonate plates that make

up the endoskeleton of an

echinoderm

Ossicle

A system of canals filled with a

watery fluid that circulates

throughout the body of an echinoderm

Water-vascular system

One of many small, flexible, fluid-filled tubes

that project from the body of an echinoderm

and that are used in locomotion, feeding, gas exchange, and excretion

Tube foot

In some protists and invertebrates,

a protective covering that the organism secretes or builds around

itselfTest

On the surface of some

echinoderms, very small pincers that

are used for protection against

ectoparasites

Pedicellaria

The porous structure through

which water enters and exits

the water-vascular system of

echinodermsMadreporite

A tube that connects the

madreporite to the ring canal

Stone canal

Canal that encircles the mouth of an echinoderm

Ring canal

Canals that extend from the ring canal down each of the

rays of the starfish, delivering water to ampullae and tube

feetRadial canal

On the upper end of a tube foot of an

echinoderm, a bulblike sac that forces water into the tube foot and causes the tube foot to

expand

Ampulla

Stomach of the sea star that can turn inside out

through its mouth; transfers food to

the pyloric stomachCardiac stomach

Stomach that connects to a pair of digestive glands

in each arm

Pyloric stomach

Bilaterally symmetrical, free-swimming larva of

a sea star

Bipinnaria

An opening from the atrial cavity to

the exterior in certain fish

Atriopore