ECHINODERMS

CREATED BY:

Chris, MacKenzie, Amelia

General Characteristics

Habitat

• Marine-bottom of deep sea trenches, sand, rubble, and coral reefs

Body Plan (symmetry)

• They have a radial body plan

Body SystemsDigestive

What do they eat?What do they eat?• Plants, animals, tiny bits of food found on ocean Plants, animals, tiny bits of food found on ocean

floor and in the waterfloor and in the waterHow do they get their food?How do they get their food?They have a mouthThey have a mouthDescribe how a sea star eats a clam: they turn Describe how a sea star eats a clam: they turn

their stomach outside their body and use their their stomach outside their body and use their feet to pry open the shell and insert their feet to pry open the shell and insert their stomach into the clam and then secrete stomach into the clam and then secrete digestive enzymesdigestive enzymes

Respiratory

Describe the water vascular system Describe the water vascular system including the tube feet:including the tube feet:

Tube feet are tiny filled tubes help gather Tube feet are tiny filled tubes help gather food, and aid in their movement. They food, and aid in their movement. They can be stretched out, have suckers in can be stretched out, have suckers in rows on the bottom of their feetrows on the bottom of their feet..

Circulatory

• What is the role of the water vascular system in the circulation: it pumps water through the body functions in feeding and gas exchange

Excretory

• What kinds of waste do echinoderms produce? Liquid, and solid

• Describe how these waste are eliminated from the body of an echinoderm: through the anus, and through the tube feet

Response/Nervous

• What is the nerve ring and a nerve net?• A nerve net is a group of nerve cells that

make a tissue called a nerve net• A nerve ring is a central ring of nerves that

branches into each of the arms• What type of sensory cells do

echinoderms have? What does each detect? Eyespots- allows them to detect light

Skeletal and Muscular (Movement)

• Describe the skeleton of an echinoderm:• It has an endoskeleton, which is

composed of individual plates called ossicles

• How is the water vascular system involved in movement? Through their tube feet they stretch out their limbs and then use the suckers on the bottom of their feet to move across the ocean floor

ReproductionReproduction

Describe asexual reproduction in echinoderms: a star Describe asexual reproduction in echinoderms: a star fish can asexually reproduce a arm is cut off with a fish can asexually reproduce a arm is cut off with a piece of the nerve ringpiece of the nerve ring

Describe sexual reproduction in echinoderms: males Describe sexual reproduction in echinoderms: males and females release their eggs, and sperm into the and females release their eggs, and sperm into the water.water.

Describe the larvae of an echinoderm:Describe the larvae of an echinoderm:Free floating larvae feed on plankton, they have bilateral Free floating larvae feed on plankton, they have bilateral

symmetry until they mature into their adulthoodsymmetry until they mature into their adulthood

Groups of Echinoderms

• Sea StarsSea Stars• The mouth lies underneath the body in the middleThe mouth lies underneath the body in the middle

• Brittle StarsBrittle Stars• Can have more than five arms, small disk and long Can have more than five arms, small disk and long

thin armsthin arms

• Sea Lilies and Feather StonesSea Lilies and Feather Stones• Most ancient and primitive, mouth located on upper Most ancient and primitive, mouth located on upper

surfacesurface

Groups of Echinoderms… cont.

• Sea Urchins And Sand Dollars• Do not have arms, some are ball shaped

• Sea Cucumbers• Can be short and wide or long and thin • No arms, mouth at one end, the mouths have

tentacles

• Sea Daisies• Disk shaped, no arms, and have tube feet

Importance's of Echinoderms

• To Ecosystem• They signify change in their environments, they

do that by dieing. They are intolerable of change

• To Humans• Fisher men often cut starfish up when found in

or on nets, this causes the starfish to grow in mass numbers

Bibliography Blaxland,Beth. Sea Stars.sea Urchins, and their Relatives. Philadelphia: Chelsea House Publisher, 2005Johnson, George B. Biology Principles and Explorations. Austin, Texas. Harcourt classroom education

company, 2001.Zubi, Teresa. “Echinoderms.” Inverebrates. 15 April 2008. 18 April 2008.

<http:www.starfish.ch/reef/echinoderms.html>.

Thanks for listening to our presentation!presentation!