http://photography.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/Photography/Images/Content/sea-star-pair-758303-sw.jpg

Echinoderm Classes

Asteroidea – Sea Stars: Multiple arms radiating from

central disk Tube feet on bottom

Riley Galton

Asteroidea – Sea Stars: Multiple arms radiating from

central disk Tube feet on bottom

Ophiuroidea – Brittle Stars: Distinct central disk with snake like arms Tube feet lack suckers

http://photography.nationalgeographic.com/staticfiles/

http://environment.nationalgeographic.com/staticfiles/

Echinoderm Classes

Echinoidea – Sea Urchins and Sand Dollars: No arms, but 5 rows of tube feet Have muscles that can move spines

Riley Galton

Echinoidea – Sea Urchins and Sand Dollars: No arms, but 5 rows of tube feet Have muscles that can move spines

http://environment.nationalgeographic.com/staticfiles/

www.emiliogrossi.com/images/Photographyiles/

Crinoidea – Feather Starsand Sea Lilies

Flexible arms used insuspension feeding

Haven’t changed in 500 millionyears

http://lh6.ggpht.com http://image44.webshots.com

Echinoderm Classes

Holothuroidea – Sea Cucumbers Reduced endoskeleton Five rows of tube feet

Riley Galton

Holothuroidea – Sea Cucumbers Reduced endoskeleton Five rows of tube feet

Concentricycloidea – Sea Daisies Only two known species Disk shaped, less than 1cm in diameter

http://blog.case.edu/case-news/2008/03/06/seacucumber.jpg

http://www.sfu.ca/~fankbone/v/xyloplax.jpg

Echinoderm SensoryStructures

Eyespots on the ends of ambulacra aresensitive to light

Pedicellariae (jaw like skeletal structures used to keep

organisms from settling on skin), tube feet, and spinesare sensitive to touch

http://www.ucmp.berkeley.edu/echinodermata/echinomm.html

Riley Galton

Eyespots on the ends of ambulacra aresensitive to light

Pedicellariae (jaw like skeletal structures used to keep

organisms from settling on skin), tube feet, and spinesare sensitive to touch

http://www.ucmp.berkeley.edu/echinodermata/echinomm.html

Echinoderm Reproduction

Sexual:• Eggs and sperm are released into the

water where they are fertilized• Larvae are planktonic• Internal fertilization has been observed

in certain species of sea stars, brittlestars, and sea cucumbers

Asexual:• Echinoderms can regenerate body

parts and organs• Asexual reproduction can occur

(though not by will) if the echinoderm istorn with enough of the body on eachpart

http://www.oceaninn.com/guides/echino.htm

Riley Galton

http://www.biolbull.org/content/vol204/issue3/images/medium/coverfig.gifSexual:

• Eggs and sperm are released into thewater where they are fertilized

• Larvae are planktonic• Internal fertilization has been observed

in certain species of sea stars, brittlestars, and sea cucumbers

Asexual:• Echinoderms can regenerate body

parts and organs• Asexual reproduction can occur

(though not by will) if the echinoderm istorn with enough of the body on eachpart

http://www.oceaninn.com/guides/echino.htmhttp://www.starfish.ch/Fotos/echinoderms

Body Cavity (Coelom)

PRESENT! Coelom = A fluid-filled cavity between body wall and gut;

lined by mesoderm Two parts:Perivisceral coelom – large, fluid-filled cavity where major

organs, digestive tube and sex organs, are suspendedWater Vascular System - network of hydraulic canals unique

to echinoderms that branches into extensions (tube feet)which function in locomotion, feeding and gas exchange

Julia Heunis

PRESENT! Coelom = A fluid-filled cavity between body wall and gut;

lined by mesoderm Two parts:Perivisceral coelom – large, fluid-filled cavity where major

organs, digestive tube and sex organs, are suspendedWater Vascular System - network of hydraulic canals unique

to echinoderms that branches into extensions (tube feet)which function in locomotion, feeding and gas exchange

http://www.colin.edu/science/awashington/syllabi/General%20Zoology%20Terminology.htm

http://biology.kenyon.edu/courses/biol112/Biol112WebPage/Syllabus/Topics/Week%207/Resources/coelom.GIF

http://www.britannica.com/EBchecked/topic/452108/perivisceral-coelom

http://www.und.nodak.edu/instruct/jvaughan/b151/VOCAB_vertebrates.html

Body Symmetry

evolved from animals with bilateralsymmetry

adult echinoderms possess radialsymmetry

All echinoderms exhibit fivefold radialsymmetry in portions of their body at somestage of life (5 parts around central axis),even if they have secondary bilateralsymmetry

For the most part…LARVAE ~ bilateralADULTS ~ radial

Julia Heunis

http://tbn2.google.com/images?q=tbn:KrJSbsj0l4ImqM:http://photos.tobinhosting.com/d/117553-2/sea%2Burchins.jpg

evolved from animals with bilateralsymmetry

adult echinoderms possess radialsymmetry

All echinoderms exhibit fivefold radialsymmetry in portions of their body at somestage of life (5 parts around central axis),even if they have secondary bilateralsymmetry

For the most part…LARVAE ~ bilateralADULTS ~ radial

http://en.wikipedia.org/wiki/Echinoderm

Excretory System

NO true excretorysystem!

Main opening of asponge used only toEXPEL WASTE

Anus leads directly fromstomach/digestive tract

Anus = topmouth = bottom

Julia Heunis

NO true excretorysystem!

Main opening of asponge used only toEXPEL WASTE

Anus leads directly fromstomach/digestive tract

Anus = topmouth = bottom

universe-review.ca

Olivia Heunis

http://universe-review.ca/I10-82-starfish.jpg

Skeletal TypeEchinodermata: “Spiny Skinned”

DO NOT possess an exoskeleton a thin outermost skin covers a mesodermal

endoskeleton made of tiny calcified plates andspines - forms rigid support contained withintissues of the organism

Skeleton composed of skeletal plates calledossicles

Ossicles = small bones In some species, such as the sea urchin, plates

of the skeleton are locked together to form arigid structure.

most sea stars and brittle stars can flex their‘arms’ = skeleton has gaps, flexible platejunctures

Julia Heunis

DO NOT possess an exoskeleton a thin outermost skin covers a mesodermal

endoskeleton made of tiny calcified plates andspines - forms rigid support contained withintissues of the organism

Skeleton composed of skeletal plates calledossicles

Ossicles = small bones In some species, such as the sea urchin, plates

of the skeleton are locked together to form arigid structure.

most sea stars and brittle stars can flex their‘arms’ = skeleton has gaps, flexible platejunctures

http://ebiomedia.com/prod/BOechinoderms.htmlhttp://en.wikipedia.org/wiki/File:Sanc0521.jpg

Other Unique Features

Echinoderms can REGENERATEex: sea cucumbers can eject a portion ofgut in response to predators andregenerate when safe

Water vascular system (described earlier)is unique to echinoderms; varies waterpressure to control tube feet

Crinoids and some brittle stars = passivefilter-feeders, absorbing suspendedparticles from passing watersea urchins = grazerssea cucumbers = deposit feedersstarfish = active hunters

Julia Heunis

Echinoderms can REGENERATEex: sea cucumbers can eject a portion ofgut in response to predators andregenerate when safe

Water vascular system (described earlier)is unique to echinoderms; varies waterpressure to control tube feet

Crinoids and some brittle stars = passivefilter-feeders, absorbing suspendedparticles from passing watersea urchins = grazerssea cucumbers = deposit feedersstarfish = active hunters

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

More Unique Features

Autonomy = The spontaneousself amputation of anappendage when the organismis injured or under attack. Theautotomized part is usuallyregenerated.

have more because ofregeneration

mutable collagenous tissue ~connect ossicles; can maintaindifferent positions withoutmuch effort

Julia Heunis

Autonomy = The spontaneousself amputation of anappendage when the organismis injured or under attack. Theautotomized part is usuallyregenerated.

have more because ofregeneration

mutable collagenous tissue ~connect ossicles; can maintaindifferent positions withoutmuch effort

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

Nervous System

Decentralized central nerve ring surrounds gut, connect

radial nerves. Radial nerves run under each arm, coordinate

movement, etc. Do not have “brains,” but some have ganglia

along radial nerves

David Lin

Decentralized central nerve ring surrounds gut, connect

radial nerves. Radial nerves run under each arm, coordinate

movement, etc. Do not have “brains,” but some have ganglia

along radial nerves

http://www.tolweb.org/Echinodermata

Digestive System

Complete digestive system(tubular gut), mouth to anus.(bottom to top)

Crinoidia: filter-feed, use cilia Asteroidea: Cardiac (evert),

pyloric stomach, digestive glands Urchins: “Aristotle’s lantern”

(masticatory apparatus) Holothurians: suspension/deposit

feeders, use tentacles.

http://www.experiencefestival.com/a/Sea_star_-_Internal_Anatomy/id/2099728

David Lin

Complete digestive system(tubular gut), mouth to anus.(bottom to top)

Crinoidia: filter-feed, use cilia Asteroidea: Cardiac (evert),

pyloric stomach, digestive glands Urchins: “Aristotle’s lantern”

(masticatory apparatus) Holothurians: suspension/deposit

feeders, use tentacles.

http://www.experiencefestival.com/a/Sea_star_-_Internal_Anatomy/id/2099728

http://userwww.sfsu.edu/~biol240/labs/lab_17hydrostaticsk/pages/echinoderm.html

Locomotion/Musculature

Utilize water vascularsystem and tube feet

Water in frommadreporite, pumped intoampulla by radial canal

Ampulla contracts, waterto podia

Podia contracts, water toampulla– Podia bend, shorten

allows movement(vacuum and suction)

David Lin

Utilize water vascularsystem and tube feet

Water in frommadreporite, pumped intoampulla by radial canal

Ampulla contracts, waterto podia

Podia contracts, water toampulla– Podia bend, shorten

allows movement(vacuum and suction)

http://animaldiversity.ummz.umich.edu/site/resources/biodidac/basicechino.jpg/medium.jpghttp://userwww.sfsu.edu/~biol240/labs/lab_17hydrostaticsk/pages/echinoderm.html

Gas Exchange

Asteroids, crinoids: dermalgills (thin epidermis)

Urchins: infolds of body wall(bursae) opening to outside

Sand dollars: modified podiaon top (petaloids) which arethin-walled and flaplike.

Holothurians: highly branchedhindgut called "respiratorytree"

David Lin

Asteroids, crinoids: dermalgills (thin epidermis)

Urchins: infolds of body wall(bursae) opening to outside

Sand dollars: modified podiaon top (petaloids) which arethin-walled and flaplike.

Holothurians: highly branchedhindgut called "respiratorytree"

http://faculty.vassar.edu/mehaffey/academic/animalstructure/outlines/echinodermata.html

Circulatory System

Mostly in perivisceralcoelom, enhanced bywater vascular systemand hemal system.– Hemal system: series

of canals and spacesmostly in coelomicchannels. Fluidmovement by cilia.Used to distributenutrients. Norespiratory system.

David Lin

Mostly in perivisceralcoelom, enhanced bywater vascular systemand hemal system.– Hemal system: series

of canals and spacesmostly in coelomicchannels. Fluidmovement by cilia.Used to distributenutrients. Norespiratory system. http://faculty.vassar.edu/mehaffey/academic/animalstructure/outlines/

echinodermata.htmlhttp://www.dailygalaxy.com/photos/uncategorized/urchins_1.jpg

Quiz

1. Echinodermata have ________ symmetry aslarvae, but display ________ symmetry as adults.

2. What allows Echinoderms to function in locomotion,feeding and gas exchange?

3. Sea stars can grow new arms and sea cucumberscan replace their gut after ejecting them. Whatfeature of echinoderms does this demonstrate?

4. Name the stomachs of a sea star. Functions?

1. Echinodermata have ________ symmetry aslarvae, but display ________ symmetry as adults.

2. What allows Echinoderms to function in locomotion,feeding and gas exchange?

3. Sea stars can grow new arms and sea cucumberscan replace their gut after ejecting them. Whatfeature of echinoderms does this demonstrate?

4. Name the stomachs of a sea star. Functions?

Answers

Bilateral, radial Water vascular

system Regeneration Cardiac, pyloric;

evert and enzymes,further digestion

Bilateral, radial Water vascular

system Regeneration Cardiac, pyloric;

evert and enzymes,further digestion