Sea Urchin Anatomy

Echinodermata means...

• stomach foot

• spiny skin

• segmented body

• jointed foot

The spines on an echinoderm are actually...

• part of the skin.

• made of chitin.

• part of the endoskeleton.

• part of the water vascular system.

Tags

NGSS.MS-LS4-2

These structures resemble long suction cups, and are part of the water vascular system.

• madreporite

• radial canals

• tube feet

• ampullae

This structure is responsible for moving water in and out of the water vascular system.

• ampullae

• madreporite

• ring canal

• radial canals

Before entering the ring canal, water must pass through the...

• stone canal

• radial canals

• ampullae

• tube feet

This water vascular system structure is centrally located, and acts like the "Grand Central Station" for water being distributed to the arms of an echinoderm.

• radial canals

• ring canal

• madreporite

• stone canal

The radial canals are lined with little structures that resemble bulb syringes called...

• stone canals

• ring canals

• madreporites

• ampullae

When water pressure is increased in the ampullae, it causes...

• death.

• an adhesive chemical to be released onto the tube feet.

• the arm of the echinoderm to move.

• the starfish to get up and walk upright.

Sea urchins are in the same clade as...

• sand dollars

• sea cucumbers

• sea stars

• brittle stars

Tags

NGSS.MS-LS4-2

A sea star can eat a bivalve by...

• prying open the shell and pulling it out using its tube feet.

• swallowing the entire shell with the bivalve inside.

• digesting the bivalve by pushing its stomach into its shell.

• using its arms to smash the shell on a rock before eating the bivalve inside.