ECHINODERMS
By: Emily Parker and Emma Cribbs
WHAT IS AN ECHINODERM?
Echinoderms are invertebrates that have radial
symmetry, a spiny skin, a water vascular system, and
a simple nervous system.
"Boundless - Textbooks." Boundless. N.p., n.d. Web. 01 Oct. 2015. <https://www.boundless.com/>.
HABITAT/ FACTS
 Strictly marine organisms
 No freshwater or terrestrial
 Referred to as “spiny skinned”
 Greek “echinos” (“spiny”)
 Greek “dermos” (“skin”)
"Sea+lilies - Google Search." Sea+lilies - Google Search. N.p., n.d. Web. 02 Oct. 2015.
<https://www.google.com/search?q=sea%2Blilies&es_sm=93&tbm=isch&tbo=u&source=univ&sa=X&ved=0CB0QsARqFQoTCPW62uzzo8gCFUt1PgodshcORA&biw=1137&bih=554&dpr=0.9&safe=active&ssui=on#safe=active&tbm=
isch&q=echinoderm+habitat&imgrc=NegFagoHe5NAFM%3A>.
"Boundless - Textbooks." Boundless. N.p., n.d. Web. 01 Oct. 2015. <https://www.boundless.com/>.
SYMMETRY/ LOCOMOTION
 Radial Symmetry, circular pattern
 Use tube feet to crawl and hold on to certain objects
 Tube feet are extendable tubes with suction cups on the ends
THE 5 MAIN CLASSES
 Asteroidea
 Ophiuroidea
 Echinoidea
 Crinoidea
 Holothuroidea
"Boundless - Textbooks." Boundless. N.p., n.d. Web. 01 Oct. 2015. <https://www.boundless.com/>.
ASTEROIDEA
 Sea Stars
 1,800+ species
 Large variety of shapes, colors, & sizes
 Thick arms that extend from central disk
"Boundless - Textbooks." Boundless. N.p., n.d. Web. 01 Oct. 2015. <https://www.boundless.com/>.
OPHIUROIDEA
 Brittle, Basket, & Snake Stars
 Long and thin arms that extend from central disk
 Brittle Stars: 5 arms
 Snake Stars: 5 arms
 Basket Stars: repeatedly branched arms
Snake Stars. N.d. Images. Web. 01 Oct. 2015.
"Boundless - Textbooks." Boundless. N.p., n.d. Web. 01 Oct. 2015. <http://www.bing.com/images/search?q=sea+lilies+and+feather+stars&view=detailv2&&id=081C9F3E4E094BBFC4E4B10A1C
<https://www.boundless.com/>.
E9000702013E43&selectedIndex=1&ccid=hmptKrw0&simid=214323628265&thid=HQ.214323628265&ajaxhist=0>.
ECHINOIDEA
 Sea urchins & Sand dollars
 Do not have any arms
 Hemispherical (flattened)
 5 rows of tube feet
"Boundless - Textbooks." Boundless. N.p., n.d. Web. 01 Oct. 2015.
<https://www.boundless.com/>.
CRINOIDEA
 Sea lilies (Feather Stars)
 Mouth on top surface
 Surrounded by feeding arms
 Can live in shallow or deep water
 Found in depths of 6,000 meters
"Boundless - Textbooks." Boundless. N.p., n.d. Web. 01 Oct. 2015. <https://www.boundless.com/>.
"Sea+lilies - Google Search." Sea+lilies - Google Search. N.p., n.d. Web. 02 Oct. 2015. <https://www.
google.com/search?q=sea%2Blilies&es_sm=93&tbm=isch&tbo=u&source=univ&sa=X&ved=0CB0QsARq
FQoTCPW62uzzo8gCFUt1PgodshcORA&biw=1137&bih=554&dpr=0.9&safe=active&ssui=on#imgrc=SWO
7L1EtkjowWM%3A>.
HOLOTHUROIDEA
 Sea Cumbers
 Also have an endoskeleton
 “Functional” bilateral symmetry (Adults)
 Lie horizontally not vertically (other Echinoderms)
"Boundless - Textbooks." Boundless. N.p., n.d. Web. 01 Oct. 2015. <https://www.boundless.com/>.
BODY SYSTEMS AND FUNCTIONS
Sea Lilies. N.d. Sea Lilies - Google Search. Web. 02 Oct. 2015.
<https://www.google.com/search?q=sea+lilies&es_sm=93&tbm=isch&tbo=u&source=univ&sa=X&ved=0CB0QsARqFQoTCPW62uzzo8gCFUt1PgodshcORA&biw=1137&bih=554&dpr=0.9&safe=
active&ssui=on#safe=active&tbm=isch&q=echinoderm &imgrc=UTSgGjOF_Bk_sM:>.
NERVOUS SYSTEM
 Nerve ring in the center
 5 radial nerves
 Does not have brain like
structure
 Have eye spots which detect
light
 Have sensory cells that support
and maintain the skeleton
"Echinoderms." Echinoderms. N.p., n.d. Web. 25 Sept. 2015.
<http://faculty.fmcc.suny.edu/mcdarby/animals&plantsbook/animals/08-
DIGESTIVE SYSTEM
 Mostly carnivorous
 Have mouth, esophagus,
stomach, intestine, rectum, and
anus.
 One way digestive system
"Echinoderms." Echinoderms. N.p., n.d. Web. 25 Sept. 2015. <http://www.mesa.edu.au/echinoderms/>.
EXCRETORY SYSTEM
 Use diffusion to rid the body of
nitrogenous waste
 Podcytes
-Cells used for filtration of bodily
fluids
 Podcytes are connected by a
system of canals
 Madreporite
-Opening used to filter water into
the WVS
Echinoderms." Echinoderms. N.p., n.d. Web. 25 Sept. 2015. <http://www.mesa.edu.au/echinoderms/>.
WATER VASCULAR SYSTEM
 Consists of a central ring canal
and radial canals
 Water circulates through and
aids in gas exchange
 Also aids in predation,
locomotion, and nutrition
 Madreporite is a key factor in
the system
Water Vascular System. N.d. Vascular System of a Starfish - Google Search. Web. 30 Sept. 2015.
<https://www.google.com/search?q=vascular+system+of+a+starfish&espv=2&biw=1137&bih=505&source=lnms&tbm=isch&sa=X&ved=0CAYQ_AUoAWoVChMI0aul2fKeyAIVw_M-Ch1kmAYf&dpr=0.9&safe=active&ssui=on#imgrc=J1NB0OMVov0maM:>
CIRCULATORY SYSTEM
 Open circulatory system
 Network of fluid, found near center of body
 Don’t have a true heart and blood
 Tissues of body are surrounded by blood
 Contains a central ring and tube feet that stretch along the body.
"Respiratory System." Respiratory System of Echinoderms. N.p., n.d. Web. 30 Sept. 2015. <https://www.google.com/search?q=circulatory%2Bsystem%2Bechinoderms&es_sm=93&source=lnms&tbm=isch&sa=X&ved=0CAcQ_AUoAWoVChMI8_SesPWeyAIViD8Ch2meQJE&biw=1137&bih=505&dpr=0.9&safe=active&ssui=on#safe=active&tbm=isch&q=gills+and+tube+feet+echinoderms&imgrc=kiam_ohz7ndT3M%3A>.
RESPIRATORY SYSTEM
 Use diffusion/ osmosis
 Use simple gills
 Tube feet take in oxygen and
pass out carbon dioxide
"Respiratory System." Respiratory System of Echinoderms. N.p., n.d. Web. 30 Sept. 2015.
<https://www.google.com/search?q=circulatory%2Bsystem%2Bechinoderms&es_sm=93&source=lnms&tbm=isch&sa=X&ved=0CAcQ_AUoAWoVChMI8_SesPWeyAIViD8-
>.
Ch2meQJE&biw=1137&bih=505&dpr=0.9&safe=active&ssui=on#safe=active&tbm=isch&q=gills+and+tube+feet+echinoderms&imgrc=kiam_ohz7ndT3M%3A
SKELETAL SYSTEM
 Endoskeleton
 Ossicles
-calcerous elements that
embedded in the body cell
- Provides protection
"Endoskeletal System." Support+or+skeletal+system+of+starfish - Google Search. N.p., n.d. Web. 30 Sept. 2015.
<https://www.google.com/search?q=support%2Bor%2Bskeletal%2Bsystem%2Bof%2Bstarfish&espv=2&biw=1137&bih=505&site=webhp&source=lnms&tbm=isch&sa=X&ved=0CAYQ_AUoAWoVChMI9uqDw_ieyAIVChY-
Reproductive System. N.d. Reproductive System Starfish - Google Search. Web. 01 Oct. 2015. <https://www.google.com/search?q=reproductive+system+starfish&es_sm=93&source=lnms&tbm=isch&sa=X&ved=0CAcQ_AUoAWoVChMIs-uqyPmeyAIVC1gCh2F1wsh&biw=1137&bih=505&dpr=0.9&safe=active&ssui=on#safe=active&tbm=isch&q= starfish gonads&imgrc=fEIAO0-4wJ_yXM:>.
REPRODUCTIVE SYSTEM
 Two sexes in echinoderms
 Each release egg and sperm
 Reproduce sexually, fertilization is
external
 Can reproduce asexually by
regeneration
 Each arm has a gonad (sex organ)
"Echinoderms." Echinoderms. N.p., n.d. Web. 25 Sept. 2015. <http://www.mesa.edu.au/echinoderms/>.
BODY STRUCTURE