period 6 justin liu antony santiago echinodermata

Period 6Period 6

Justin Liu

Antony SantiagoEchinodermataEchinodermata

Echinoderms

Classes

Asteroidea

Click to Select a TopicClick to Select a Topic

Holothuroidea

Concentricycloidea

Body Plans

Excretion

Response

Movement

Ophiuroidea

Echinoidea

Crinoidea

Feeding and Digestion

Respiration

Circulation

Reproduction

Works Cited

Home

General Characteristics of General Characteristics of EchinodermsEchinoderms

• 6000 species6000 species

• Pentamerous radial symmetry- the body can Pentamerous radial symmetry- the body can be divided into five parts around a main axisbe divided into five parts around a main axis

• Water vascular system- a hydraulic network Water vascular system- a hydraulic network of canals that run through the body, usually of canals that run through the body, usually ending in a series of tube feetending in a series of tube feet– The organism can control internal water pressure The organism can control internal water pressure

to extend/contract tube feet for locomotion, food to extend/contract tube feet for locomotion, food collection, and respirationcollection, and respiration

General Characteristics of General Characteristics of Echinoderms cont.Echinoderms cont.

• Internal skeleton covered with spines and Internal skeleton covered with spines and skinskin– Consists of multitudes of ossicles (small Consists of multitudes of ossicles (small

calcareous plates) forming flexible jointscalcareous plates) forming flexible joints

• Some species of sea stars actually extend Some species of sea stars actually extend their stomachs into their victims in order their stomachs into their victims in order to digest themto digest them

General Characteristics of General Characteristics of Echinoderms cont.Echinoderms cont.

• A system of endoskeletal elements A system of endoskeletal elements composed of a calcareous meshwork composed of a calcareous meshwork called the stereomcalled the stereom

• Construction of ambulacra (a radial Construction of ambulacra (a radial area bearing tube feet) by the area bearing tube feet) by the addition of new plates adjacent to addition of new plates adjacent to the terminal, or ocular, plate that the terminal, or ocular, plate that marks the ends of the radial canals.marks the ends of the radial canals.

• A diffuse sub-epithelial nervous A diffuse sub-epithelial nervous systemsystem

ClassesClasses

• There are six classes in the phylum There are six classes in the phylum Echinodermata.Echinodermata.– AsteroideaAsteroidea– OphiuroideaOphiuroidea– EchinoideaEchinoidea– CrinoideaCrinoidea– HolothuroideaHolothuroidea– ConcentricycloideaConcentricycloidea

Asteroidea (The Sea Stars)Asteroidea (The Sea Stars)

http://www.biodiversityexplorer.org/mm/echinoderms/asteroidea/index.htm

Ophiuroidea (The Brittle Stars)Ophiuroidea (The Brittle Stars)

http://www.eol.org/pages/2037

http://www.portalsaofrancisco.com.br/alfa/filo-equinodermata/filo-equinodermata-6.php


Echinoidea Echinoidea (The Sea Urchins and Sand (The Sea Urchins and Sand

Dollars)Dollars)

http://oceanlink.island.net/biodiversity/ask/echino.html



Crinoidea Crinoidea (The Sea Lilies and Feather (The Sea Lilies and Feather

Stars)Stars)


Holothuroidea (Sea Holothuroidea (Sea Cucumbers)Cucumbers)


ConcentricycloideaConcentricycloidea (Sea (Sea Daisies)Daisies)

http://www.mhhe.com/biosci/genbio/raven6b/graphics/raven06b/other/raven06_47.pdf

Body PlansBody Plans

• Bilateral Symmetry [in larvae]-left and Bilateral Symmetry [in larvae]-left and right sides of an organism can be divided right sides of an organism can be divided into mirror images of each otherinto mirror images of each other

• Radial Symmetry [in adults]-symmetrical Radial Symmetry [in adults]-symmetrical arrangement of parts of an organism arrangement of parts of an organism around a single main axisaround a single main axis

• All echinoderms exhibit All echinoderms exhibit secondary radial secondary radial symmetrysymmetry, because they exhibit bilateral , because they exhibit bilateral symmetry during larval development, but symmetry during larval development, but exhibit radial symmetry as adults.exhibit radial symmetry as adults.

Feeding and DigestionFeeding and Digestion

• Echinoderms have a stomach and mouth Echinoderms have a stomach and mouth areaarea– Some echinoderms, such as sea cucumbers Some echinoderms, such as sea cucumbers

have a mouth on the bottom side of their have a mouth on the bottom side of their body, and an anus on the front of their body.body, and an anus on the front of their body.

• In some echinoderms the tube feet are In some echinoderms the tube feet are important sensory organs and assist in important sensory organs and assist in directing food into the mouth once the directing food into the mouth once the animal has captured itanimal has captured it

Feeding and Digestion Cont.Feeding and Digestion Cont.

• Some echinoderms are carnivorous Some echinoderms are carnivorous and scavenge the ocean floor.and scavenge the ocean floor.

• Others such as feather stars and sea Others such as feather stars and sea cucumbers are mainly filter feeders, cucumbers are mainly filter feeders, and catch food in ocean currents.and catch food in ocean currents.

• Certain species, such as the sea star, Certain species, such as the sea star, actually extend their stomach into an actually extend their stomach into an unwary victim to digest it.unwary victim to digest it.

RespirationRespiration

• Poorly developed respiratory systemPoorly developed respiratory system

• Most echinoderms take in oxygen Most echinoderms take in oxygen across the skin through small across the skin through small fingerlike extensions of the coelem fingerlike extensions of the coelem (main body cavity) called papulae.(main body cavity) called papulae.

• The papulae are covered with a thin The papulae are covered with a thin layer of skin and protrude through layer of skin and protrude through the body wall to function as gills.the body wall to function as gills.

CirculationCirculation

• Echinoderms have a simple circulatory Echinoderms have a simple circulatory system that pumps water through its body.system that pumps water through its body.– echinoderms have an open circulatoryechinoderms have an open circulatory

systemsystem with cilia circulating the fluids through with cilia circulating the fluids through each arm. each arm.

• The echinoderm’s coelom, or main body The echinoderm’s coelom, or main body cavity, connects with a complicated system cavity, connects with a complicated system of tubes that helps to provide circulationof tubes that helps to provide circulation

ExcretionExcretion

• Amoeboid cells, which are foreign to Amoeboid cells, which are foreign to the echinoderm, carry wastes out of the echinoderm, carry wastes out of the coelomic fluid. the coelomic fluid.

• Waste removal also occurs through Waste removal also occurs through small fingerlike extensions of the small fingerlike extensions of the coelem called the papulae.coelem called the papulae.

• The process of excretion in The process of excretion in echinoderms also makes use of the echinoderms also makes use of the echinoderm’s water vascular system.echinoderm’s water vascular system.

ResponseResponse

• Have a poorly developed nervous system Have a poorly developed nervous system and lack a brainand lack a brain

• Echinoderms have a light sensitive organ Echinoderms have a light sensitive organ called a eyespot that can detect light and called a eyespot that can detect light and its general direction, which allows the its general direction, which allows the echinoderm to move in response to light.echinoderm to move in response to light.

• In some echinoderms their skin cells may In some echinoderms their skin cells may be sensitive to certain chemicals given be sensitive to certain chemicals given off by prey or predatorsoff by prey or predators

MovementMovement

• All echinoderms possess an internal skeletonAll echinoderms possess an internal skeleton• In sea stars and brittle stars, the skeleton is made up In sea stars and brittle stars, the skeleton is made up

of small calcareous plates (ossicles) which form of small calcareous plates (ossicles) which form flexible joints that can be used for movement.flexible joints that can be used for movement.

• An echinoderms tube feet work to enable movementAn echinoderms tube feet work to enable movement– Canals of small muscular tubes (water vascular Canals of small muscular tubes (water vascular

system) supplies water to the tube feet.system) supplies water to the tube feet.– As tube feet press against a moving object, water As tube feet press against a moving object, water

is then withdrawn from the tube feet, which is then withdrawn from the tube feet, which results in a suction effect.results in a suction effect.

– When water returns to the canals the suction of When water returns to the canals the suction of the tube feet is released.the tube feet is released.

– This type of movement is generally very slow.This type of movement is generally very slow.

ReproductionReproduction

• Echinoderms are classified as Echinoderms are classified as deuterostomesdeuterostomes– In deuterostomes, the blastopore (the In deuterostomes, the blastopore (the

first opening that appears in the first opening that appears in the embryo) becomes the animal’s anusembryo) becomes the animal’s anus

– Deuterostomes exhibit indeterminate Deuterostomes exhibit indeterminate development in which none of the development in which none of the daughter cell’s have a predetermined daughter cell’s have a predetermined function and some daughter cells could function and some daughter cells could even form a new organism.even form a new organism.

Reproduction cont.Reproduction cont.

•Some echinoderms are diecious, Some echinoderms are diecious, meaning that there are separate meaning that there are separate female and male individuals.female and male individuals.

•The males and females discharge The males and females discharge their sperm and eggs, respectively, their sperm and eggs, respectively, into the water to be fertilizedinto the water to be fertilized

•A female can release one hundred A female can release one hundred million eggs at oncemillion eggs at once

Reproduction cont.Reproduction cont.

• Echinoderms usually perform sexual Echinoderms usually perform sexual reproduction, while some species reproduction, while some species perform asexual reproductionperform asexual reproduction

• Sexual reproduction involves the external Sexual reproduction involves the external fertilization of eggs by spermatozoa.fertilization of eggs by spermatozoa.

• Asexual Reproduction usually involves Asexual Reproduction usually involves the division of the body into two or more the division of the body into two or more parts (fission) and the reproduction of parts (fission) and the reproduction of missing body parts. missing body parts.

Works CitedWorks Cited

• Lambert, Phil. "Echinoderms of BC." Lambert, Phil. "Echinoderms of BC." UBC UBC Department of Department of GeographyGeography. Web. 20 Apr. 2010. . Web. 20 Apr. 2010.

<http://www.geog.ubc.ca/biodiversity/efauna/Echin<http://www.geog.ubc.ca/biodiversity/efauna/EchinodermsofBC.html>. odermsofBC.html>.

• EchinodermsEchinoderms. Web. 20 Apr. 2010. . Web. 20 Apr. 2010. <http://www.mcwdn.org/Animals/Starfish.html>.<http://www.mcwdn.org/Animals/Starfish.html>.

• Wonders of the Sea: EchinodermsWonders of the Sea: Echinoderms. Oceanside . Oceanside Meadows Meadows Innstitute for the Arts and Sciences. Innstitute for the Arts and Sciences. Web. 20 Apr. Web. 20 Apr. 2010. 2010. <http://www.oceaninn.com/guides/echino.htm>.<http://www.oceaninn.com/guides/echino.htm>.

• Raven, Peter, George Johnson, Susan Singer, and Raven, Peter, George Johnson, Susan Singer, and Jonathan Losos. "Echinoderms." Jonathan Losos. "Echinoderms." BiologyBiology. Sixth . Sixth

ed. ed. McGraw-Hill Companies, 2001. 933-44. Print.McGraw-Hill Companies, 2001. 933-44. Print.

Thank YouThank You

period 6 justin liu antony santiago echinodermata

Documents

respiration slide

sea stars http

cited home slide

species of sea stars

radial canals

feather stars http

brittle stars http

sea urchins