Echinodermata tina sunny mihaela 10 6

Echinodermata(Sea Stars)Konstantina Stefanova

Mihaela Kozanova

Alexandra Panusheva

10/6

Phylogenetic Tree (7)

• Domain: Eukaryots

• Kingdom: Animalia [Metazoa]

• Main Phylum: Deuterostromia

• Phylum: Echinodermata

• Class: Asteroidea

• Clade: sea stars (7)

Echinodermata (2)

• Origin of the name – Greek: ἐχινός- echinos ,and δέρμα – derma; “spiny skin”

• A taxon that incorporates 7000 marine animals second largest division of the Deuterostromia main phylum after the Chordates

• The largest group of living species that doesn’t consist of terrestrial or freshwater members

• The earliest representatives date from the Cambrian period• Significance:

- biologically: one of the most deep sea and shallow ocean groups

- geologically: production of limestone from the decayed bodies of echinodermata representatives (2)

http://www.starfish.ch/c-invertebrates/seesterne.html

Symmetry (1)• Symmetry:

Evolve from organisms with bilateral symmetry

Larvae – initially bilateral symmetry

Adult organisms – radial symmetry; body arranged around an axis in five parts (1)

http://www.animalwebguide.com/Starfish.htm

http://www.geneseo.edu/~antarc/week3/image9.jpg

Taxon Relationship (7)• Main Phylum: Deuterostromia

Echinodermata Hemichordata Chordata

• Surprisingly, vertebraes belong to the Chordata phylum, which makes them closely related to Echinodermata, or sea stars.

• Common ancestry with humans: 500 million years ago (7)

Derived Characteristics (3)• Ossicles covering the skeleton – calcite in

tiny crystals; mostly as an endoskeletonforming a tough, but flexible covering

• Water vascular system –a network of canals extending to the tubefeet (radial canal; madreporite ); for feeding, locomotion, and respiration

• radial canal• madreporite

• Collagenous tissue – ligaments connecting the ossicles, thus making them “locked” or “unlocked”; mechanical advantages

• Symmetry and body organization (3)

http://upload.wikimedia.org/wikipedia/commons/4/4c/Madreporenplatte.jpg

Sea Star (Starfish)

(8) • Inhabit all world’s oceans (Indian, Pacific, Arctic, Atlantic, etc)

• There are more than 1800 representatives

• Live in both shallow and deep waters (more than 6000m)

• Typical characteristics: regeneration of body parts and eating mussels (8)

http://en.wikipedia.org/wiki/File:Starfish_komodo.jpg

http://en.wikipedia.org/wiki/File:Sun_flower_sea_star_in_tide_pools.jpg

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

Reproduction (8)• Sexual:

External Male and female sea stars give off their gametes in the

environment (water) Fertilization takes place in the water between gametes from the

opposite sex Embryos – part of the zooplankton Gather in groups to increase chances of reproduction, thus

using environmental and chemical signals to show readiness• Asexual

Part of the body developing into a separate and independent organism

An arm is possible to regenerate into a separate organism only if part of the central ring is in the arm (8)

http://www.youtube.com/watch?v=7uj15vMXc30

Nervous System • Complex decentralized system (1)• Nerve plexus (a system of interlacing nerves) runs inside

and under the skin of the starfish (8)• A central disk that includes a nerve ring is located

around the esophagus and its primary function is to give start to nerve cords (1)

• Nerve cords – situated in the arms; ensure balance + orientation (8)

• Lack of sense organs, but sensibility to light (eye spots), touch (tube feet, spine), temperature, orientation and water condition (8)

Digestive System

• Food: both plants and animals (8)• As the mouth opens, it turns into a two

layered (back and front part) stomach (1)• When the food enters, enzymes are released by digestive glands to break

down the food (1)• The waste products are transported by a short intestine to the anus (8)• Swallowing their prey (clams + oysters): (1)

• The whole prey enters the mouth (8)• The stomach goes out of the body in order to capture the prey (1)• In the case of shells: the prey is caught by the tube feet and the cardiac

(front) stomach enters the shell, eats out its content, which then goes to the pyloric (back) stomach where it is further broken down (8)

http://en.wikipedia.org/wiki/File:Starfishmussel.jpg

Sea Cucumbers (4)• Latin name: Holothuria• Representatives of the Holothuroidea class• Live on the sea floor, or floating to move to new location, except the strawberry sea cucumber, which lives on the rocks • Location: Florida Reef, New Zealand (Pacific Ocean)• Diet: plankton, decaying organisms, eat with the help of feeding

tentacles• Locomotion: its tube feet help it for crawling along• Ecological role: support the life cycle by serving as food• while eating other organism• Human uses: food, medicine• Fun Fact: inspiration (haiku, song, novel) (4)

http://en.wikipedia.org/wiki/File:Espardenya_(animal).jpg

Sea Daisies (9) • Latin name: Asteriscus Maritimus • Representative of Concentricycloidea class• Found only on pieces of wood that have sunk below 1000m• Location: only in New Zealand (Pacific ocean), and the Bahamas• Diet: bacteria, decaying organisms on sunken woods; micro –

molluskus• Locomotion: they can move through a series of pulsations

movements of stomach• Ecology role: support the life cycle by serving as food• while eating other organism• Human use: no interaction with humans• Fun Fact: they are as big as a pencil’s diameter; also do not have

mouth, guts, or anus (9)

http://www.teara.govt.nz/files/a5200eta.gif

Sea Urchin• Latin name: Sterechinos Neumayeri (6)• Representatives of Echinoidea class (5)• They are found in all oceans and almost all seas (6)• Location: example of location is White sea (Greece), Pacific ocean

(New Zealand) (6)• Diet: plants, decaying matter, dead fish, sponges, mussels,

seaweed (5)• Locomotion: have five rows of tube feet that function for slow motion• Ecology role: support the life cycle by serving as food (6)• while eating other organism• Human use: food (6)• Fun Fact: can be combined with cream, soy sauce, butter, etc. (6)

http://www.scubaequipmentusa.com/marine/NOV04/images/Heliocidaris_erythrogramma.jpg

Human Uses/ Interactions• Delicacy

• Sea Urchins - more than 50, 000 tons of are captured per year; distributed and consumed primarily in Japan, Peru, France; characterized with soft taste, as of a mixture of fruit and seafood (6)

• Sea Cucumbers – delicacy in south-east Asia; eaten when dried only if the poisonous parts have been removed; medicine – prevent the growth of tumor cells in the body (4)

• Source of lime in parts of the world where limestone is not available (6)

• Decoration (6)

http://en.wikipedia.org/wiki/File:Uniryori.jpghttp://img4.coastalliving.com/i/2008/12/christmas-wreath-8-l.jpg

Work Cited • Campbell, Neil A., and Jane B. Reece. Biology. 18th ed. San Francisco:

Pearson, Benjamin Cummings, 2008. Print. (1)• "Echinoderm." Wikipedia, the Free Encyclopedia. Web. 28 Mar. 2010.

<http://en.wikipedia.org/wiki/Echinoderm>. (2)• "Echinodermata." Tree of Life Web Project. Wray, Gregory. Web. 28 Mar. 2010.

<http://tolweb.org/Echinodermata>. (3)• "Sea Cucumber." Wikipedia, the Free Encyclopedia. Web. 28 Mar. 2010.

<http://en.wikipedia.org/wiki/Sea_cucumber>. (4)• "Sea Urchin." Echanted Learning. Web. 28 Mar. 2010.

<http://www.enchantedlearning.com/subjects/invertebrates/echinoderm/Seaurchin.shtml>. (5)

• "Sea Urchin." Wikipedia, the Free Encyclopedia. Web. 28 Mar. 2010. <http://en.wikipedia.org/wiki/Sea_urchin>. (6)

• Speer, Brian. "UCMP Web Lift to Taxa." UCMP - University of California Museum of Paleontology. 18 Apr. 1996. Web. 28 Mar. 2010. <http://www.ucmp.berkeley.edu/help/taxaform.html>. (7)

• "Starfish." Wikipedia, the Free Encyclopedia. Web. 28 Mar. 2010. <http://en.wikipedia.org/wiki/Starfish>. (8)

• “Sea Daisy.” Wikipedia, the Free Encyclopedia. Web. 28 Mar. 2010. <http://en.wikipedia.org/wiki/Sea_daisy>. (9)