Crustaceans and Echinoderms

Crustaceans and Echinoderms, while sharing many of the same watery homes, are more different than they are similar.

One singular similarity between the two sorts of creatures is that they are both invertebrates.

However, there is an absolute plethora of differences:

• Crustaceans have bilateral symmetry, whilst echinoderms have radial symmetry.
• Crustaceans have hard exoskeletons, and echinoderms have endoskeletons.
• Echinoderms are far more sessile than crustaceans.
• Echinoderms leave behind tests, which are their endoskeleton remains; crustaceans do not.
• Crustaceans go through molting, while echinoderms do not. 
• Echinoderms move with their tube feet, but crustaceans move with walking feet.
• Crustaceans have segmented bodies, but echinoderms do not!
• Echinoderms have spiky skin made of calcium carbonate, but crustaceans in turn have jointed legs and feet (they're arthropods). 
• Crustaceans have more complex nervous systems than echinoderms. 

 Here are some photos of these nifty creatures, followed by their taxonomy (scientific classification):

First, some echinoderms... 

Animalia echonodermata asteroidea spinulosida acanthasteridae acanthaster planci

http://digital.library.colostate.edu/cgi-bin/pview.exe?CISOROOT=/garst&CISOPTR=60&CISORESTMP=/garst/html/garst_template1.html&CISOVIEWTMP=/garst/html/garst_template2.html&CISOMODE=thumbnails&CISOROWS=2&CISOCOLS=4

 Eukarya animalia echinodermata asteroidea forcipuladita asteriidae pycnopodia helianthoides

http://cdn1.arkive.org/media/2B/2B9B3E72-D665-4A7D-9560-EBBC4A9EA908/Presentation.Large/Sunflower-star-predating-on-sea-cucumber.jpg&imgrefurl=http://www.arkive.org/sunflower-star/pycnopodia-helianthoides/&usg=__nDmv2q-hz2DlvHVvxYv2oALDSyQ=&h=430&w=650&sz=68&hl=en&start=12&sig2=otTd6j2dicNxjqnnxmD7Mg&zoom=1&tbnid=24J6xqnnvxy2vM:&tbnh=91&tbnw=137&ei=5rV_TZKgNeG40QG8gpWDCQ&prev=/images%3Fq%3Dsunflower%2Bstar%26hl%3Den%26safe%3Dactive%26biw%3D1024%26bih%3D576%26gbv%3D2%26tbs%3Disch:10%2C228&itbs=1&biw=1024&bih=576

Eukarya Animalia Echinodermata Asteroidea Forcipulatida Asteriidae Pycnopodia helianthoides

http://www.racerocks.com/racerock/eco/taxalab/ensy02/gorgonocephalus/baskcentre.jpg

Now for some crustaceans!
Animalia arthropoda malacostraca  decapoda graspidae graspus

http://digital.library.colostate.edu/cgi-bin/pview.exe?CISOROOT=/garst&CISOPTR=1158&CISORESTMP=/garst/html/garst_template1.html&CISOVIEWTMP=/garst/html/garst_template2.html&CISOMODE=thumbnails&CISOROWS=2&CISOCOLS=4

Eukaryota animalia metazoa arthropoda crustacea malacostraca eumalacostraca eucarida decapoda pleacyemata brachyura

http://laterallineco.com/blog/2009/01/page/2/&usg=__Pgw7mTWFH2PYdRV2flYOysRuBQ0=&h=391&w=500&sz=432&hl=en&start=0&sig2=aeP-Ts80l9TOvKj_LZdcRA&zoom=1&tbnid=vtIwPRSRNHuvBM:&tbnh=134&tbnw=190&ei=lLN_TYOLMKq40QGm2c2TCQ&prev=/images%3Fq%3Dblue%2Bcrab%26um%3D1%26hl%3Den%26safe%3Dactive%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official%26biw%3D1024%26bih%3D576%26tbs%3Disch:1&um=1&itbs=1&iact=rc&dur=231&oei=lLN_TYOLMKq40QGm2c2TCQ&page=1&ndsp=13&ved=1t:429,r:2,s:0&tx=120&ty=101

 Metazoa Arthropoda Malacostraca Decopoda Ocypodidae Ocypode

http://www.aquaessence.com/image/store/0/productImages/ghostCrab.jpg&imgrefurl=http://www.aquaessence.com/index.cfm/m/38/fuseaction/store5products.productDetail/productID/120/merchantId/0/departmentId/0/categoryId/34&usg=__eUNLBJS4sd8tLdPmkif7wIkZN5U=&h=480&w=640&sz=37&hl=en&start=0&sig2=3MfruFZc4ymHWjFpmGFgyg&zoom=1&tbnid=Yc90pZsgBb2K9M:&tbnh=133&tbnw=201&ei=pLd_Ta31AY6atwfG2entCA&prev=/images%3Fq%3Dghost%2Bcrab%26um%3D1%26hl%3Den%26safe%3Dactive%26gbv%3D2%26biw%3D1024%26bih%3D576%26tbs%3Disch:10%2C95&um=1&itbs=1&iact=hc&vpx=522&vpy=136&dur=245&hovh=194&hovw=259&tx=162&ty=128&oei=lLd_Ta3oI8-gtgew2oXOCA&page=1&ndsp=12&ved=1t:429,r:6,s:0&biw=1024&bih=576

 Check out this AWESOME video of a nocturnal sea star!