EchinodermEchinoderm

Hristova, AleksandraHristova, Aleksandra

Kounov, PavelKounov, Pavel

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EchinodeEchinodermrm•Phylum of marine animals•Known as “Sea stars”•7000 living species•Name comes from Greek

–Echin – Spiny–Derma – skin [3]

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http://www.graphicmania.net/wp-content/uploads/sea-star-pair-758303-ga.jpg

SymmetrySymmetry•Adults – redial symmetry Adults – redial symmetry •Larvae – bilateral symmetry Larvae – bilateral symmetry

[2][2]

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http://dj003.k12.sd.us/images/32-05-BodySymmetry-L.gif

AnatoAnatomymy • Central disk- have Central disk- have

nerve rings and nerve nerve rings and nerve cord on the armscord on the arms

• Digestive glands- Digestive glands- have digestive juices have digestive juices that help storage of that help storage of nutrientsnutrients

• Radial canal- fluid Radial canal- fluid containing, form the containing, form the water vascular systemwater vascular system

• Madreporite- where Madreporite- where the water flow in or the water flow in or out [1]out [1]

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http://www.biog1105-1106.org/labs/deuts/media/echinowatervasc.jpg

Ancestors and Place in Ancestors and Place in the Cladogramthe Cladogram

• Kingdom: Kingdom: AnimaliaAnimalia• Subkingdom: Subkingdom: EumetazoaEumetazoa• Superphylum: Superphylum: DeuterostomiaDeuterostomia• Classes: Classes: 66

– Crinoidea, Ophiuroidea, Asteroidea, Crinoidea, Ophiuroidea, Asteroidea, Holothuroidea, Echinoidea, Holothuroidea, Echinoidea, ConcentricycloideaConcentricycloidea

• Most close to the BirdsMost close to the Birds• All classes of Echinoderm came from All classes of Echinoderm came from

Crinoidea [3] Crinoidea [3]

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Cladograms

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http://www.geog.ubc.ca/biodiversity/efauna/images/lophotrochozoa.jpg

http://image.absoluteastronomy.com/images/encyclopediaimages/n/ne/neoaves_alternative_cladogram.png

CharacteriCharacteristicsstics

• Water vascular system (Derived)– Network of fluid-filled canals- tube

foots– Gas exchange, feeding, locomotion

• Decentralized nervous system– Interconnected neurons with no

central brain– Ganglion- tissue of nerve cells

• Skeleton– Ossicles, calcium carbonate, and

several proteins [3]7

RegeneraRegenerationtion• The process in which

damaged or lost body parts re-grow

• Echinoderm may discharge parts when feeling danger

• These parts are quickly regenerated

• Leads to reproduction [2]

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http://fotosa.ru/stock_photo/Animals/p_63747.jpg

ReproductionReproductionSexualSexual

• 2-3-year-old• Egg and sperm are

released in the water

• In 3 species (sea cucumbers, sea stars, and brittle stars) – internal fertilization [3]

AsexualAsexual

• Sea stars and Brittle stars

• When a sea star loses an arm, it regenerates the arm and the arm regenerates the rest of the body. [2]

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Avoiding Avoiding PredationPredation•Many animals such as sharks and Many animals such as sharks and

crabs eat echinodermscrabs eat echinoderms•So EVOLUTIONSo EVOLUTION•Toxins delivered by the tube feetToxins delivered by the tube feet•Discharge of sticky entangling Discharge of sticky entangling

threatsthreats•Painful injuries when touching [3]Painful injuries when touching [3]

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FeedingFeeding• Different for every species• Shellfish, sea stars, particles in the water• Crinoids – when food particles touches the

surface the tube feet push them to the mouth

• Sea cucumbers – suck large amount of water and absorb the useful particles

• Sea stars lock their arms around the victim, release gastric juices and digest the animal alive [3]

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Representatives of the Representatives of the Phylum Phylum • Sea StarsSea Stars• Sand DollarsSand Dollars• Feature StarFeature Star

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http://irati.pnte.cfnavarra.es/cpsadrw/la_voz_menuda/blogs/media/blogs/ingles/seastar.jpg

http://www.animalpictures1.com/data/media/109/Sand_Dollar-2.jpg

http://www.onearth.com/gallery/seafeatuer.jpg

Sea StarsSea Stars• Multiple armsMultiple arms• Moves when the tube feet extend, Moves when the tube feet extend,

grip and releasegrip and release• Tube feet catch clams and oystersTube feet catch clams and oysters• RegenerationRegeneration• Live everywhere in the oceans [1]Live everywhere in the oceans [1]

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Sand DollarsSand Dollars• Have no armsHave no arms• Five rows of tube feet -> motionFive rows of tube feet -> motion• Flat disksFlat disks• Catch small organisms with the tube Catch small organisms with the tube

feet that they can swallow wholefeet that they can swallow whole• Lives everywhere in the oceansLives everywhere in the oceans• Ecological role – cleans the sea floor Ecological role – cleans the sea floor

from food particles [1]from food particles [1]

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Feature StarFeature Star•Crawl using flexible armsCrawl using flexible arms•Swallow big amounts of Swallow big amounts of

water and eat the useful water and eat the useful particles (suspension eating)particles (suspension eating)

•Lives everywhere in the Lives everywhere in the oceans [1]oceans [1]

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Human Human InteractionsInteractions• May get injuries from a sea

urchin• Sushi

– 50 000 kg of sea urchins and sea cucumbers are captured every year in Japan, Peru and France. [3]

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http://i270.photobucket.com/albums/jj96/beaubienb/sushi.jpg

Fun FactFun Fact•Echinoderms have pigment

cells•Their color is caused by the

sun light [3]

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http://www.perfumezilla.com/images_product/lancaster-sun-protection-precious-sun-global-protection-cellular-support-spf-women545313.jpg

Work CitedWork Cited• Campbell, Neil A. Campbell, Neil A. BiologyBiology. Boston: Pearson, 2008. . Boston: Pearson, 2008.

Print. [1]Print. [1]• Wray, Gregory A. "Echinodermata." Wray, Gregory A. "Echinodermata." Tree of LifeTree of Life. .

Duke University, 14 Dec. 1999. Duke University, 14 Dec. 1999.      Web. 29 Mar. 2010.      Web. 29 Mar. 2010. <http://tolweb.org/Echinodermata>. [2]<http://tolweb.org/Echinodermata>. [2]

• Wikipedia. "Echinoderm." Wikipedia. "Echinoderm." WikipediaWikipedia. Wikipedia, . Wikipedia, n.d. Web. 29 Mar. 2010. n.d. Web. 29 Mar. 2010.      http://en.wikipedia.org/wiki/Echinoderm [3]     http://en.wikipedia.org/wiki/Echinoderm [3]..