ADW: Platyhelminthes: INFORMATION

<!DOCTYPE html> <html xmlns:og="http://ogp.me/ns#" lang="en" xml:lang="en"> <head> <title>ADW: Platyhelminthes: INFORMATION</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <link rel="canonical" href="https://animaldiversity.org/accounts/Platyhelminthes/" /> <script type="text/javascript" src="//code.jquery.com/jquery-3.6.0.min.js"></script> <script type="text/javascript" src="//code.jquery.com/jquery-migrate-3.3.2.min.js"></script> <script type="text/javascript" src="/static/js/compat.js"></script> <link rel="shortcut icon" href="https://animaldiversity.org/favicon.ico" /> <link href="//fonts.googleapis.com/css?family=Gentium+Book+Basic:400,400italic,700,700italic" rel="stylesheet" type="text/css" /> <link href="//fonts.googleapis.com/css?family=PT+Sans:400,700,400italic,700italic" rel="stylesheet" type="text/css" /> <link rel="stylesheet" type="text/css" href="/static/bootstrap/css/bootstrap.css" /> <link rel="stylesheet" href="/static/css/pica.styles.css" /> <link rel="stylesheet" href="/static/css/pica.print.css" media="print" />  <link rel="stylesheet" type="text/css" href="/static/colorbox/colorbox.css" /> <meta property="og:url" content="https://animaldiversity.org/accounts/Platyhelminthes/" /> <meta content="Platyhelminthes (flatworms)" property="og:title" /> <meta content="website" property="og:type" /> <meta content="Animal Diversity Web" property="og:site_name" /> <meta content="https://animaldiversity.org/collections/contributors/Grzimek_inverts/Monogenea/Gyrodactylus_pungitii/medium.jpg" property="og:image" /> <meta name="twitter:card" content="summary" /> <meta name="twitter:site" content="@AnimalDiversity" /> <meta name="twitter:title" content="Platyhelminthes (flatworms)" /> <meta name="twitter:description" content="Read about Platyhelminthes (flatworms) on the Animal Diversity Web." /> <meta name="twitter:image:src" content="https://animaldiversity.org/collections/contributors/Grzimek_inverts/Monogenea/Gyrodactylus_pungitii/medium.jpg" /> <meta name="twitter:image:height" content="480" /> <meta name="twitter:image:width" content="189" /> <meta name="twitter:url" content="https://animaldiversity.org/accounts/Platyhelminthes/" /> <script type="text/javascript" src="/static/js/Hyphenator.js"></script> <link rel="stylesheet" href="/static/social-likes/social-likes_birman.css" /> <style> .social-likes { margin: 0; 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Some forms are free living but many are parasitic. Flatworms have a cephalized nervous system that consists of head ganglion, usually attached to longitudinal nerve cords that are interconnected across the body by transverse branches. Excretion and osmoregulation by flatworms is controlled by "flame cells" located in protonephridia (these are absent in some forms). Flatworms lack a respiratory or circulatory system; these functions take place by absorption through the body wall. Nonparasitic forms have a simple, incomplete gut; even this is lacking in many parasitic species.</p> <p>Movement in some flatworms is controlled by longitudinal, circular, and oblique layers of muscle. Others move along slime trails by the beating of epidermal cilia. The development of directional movement is correlated with cephalization. In some flatworms, the process of cephalization has included the development in the head region of light-sensitive organs called ocelli. Other sense organs found in at least some members of this group (not necessarily on the head) include chemoreceptors, balance receptors (statocysts), and receptors that sense water movement (rheoreceptors).</p> <p>Most flatworms can reproduce sexually or asexually. Most are monoecious. Most of these have developed ways of avoiding self-fertilization. Development may be direct (eggs hatch into tiny worms that resemble the adults) or indirect (with a ciliated larval form).</p> <p>Flatworms include a large number of parasitic forms, some of which are extremely damaging to human populations.</p> <hr /> <p> <em>Click on the name of a Class below to learn more:</em> </p> <ul class="simple"> <li>Class <a class="taxon-link" href="/accounts/Turbellaria/">Turbellaria</a> (turbellarians, flatworms)</li> <li>Class <span class="taxon-name">Monogenea</span> (parasitic flukes)</li> <li>Class <a class="taxon-link" href="/accounts/Trematoda/">Trematoda</a> (parasitic flukes)</li> <li>Class <a class="taxon-link" href="/accounts/Cestoda/">Cestoda</a> (tapeworms)</li> </ul> <hr /> <p><strong>Source</strong>:</p> <p>Hickman, C.P. and L. S. Roberts. 1994. <em>Animal Diversity</em>. Wm. C. Brown, Dubuque, IA.</p> <p>Brusca, R. C., and G. J. Brusca. <em>Invertebrates.</em> 1990. Sinauer Associates, Sunderland, MA.</p> </section> <section class="hyphenate"> <h3 id="contributors">Contributors</h3> <p>Phil Myers (author), Museum of Zoology, University of Michigan-Ann Arbor. </p> </section> </div> </div> <div class="span2_5 right sidebar"> <div class="well" id="pocket-guide-link"> <a href="https://itunes.apple.com/us/app/adw-pocket-guide/id916179421?mt=8" target="_blank"><i class="icon-download icon-white" style="vertical-align: bottom"></i> ADW Pocket Guides on the iOS App Store! </a> <p>The Animal Diversity Web team is excited to announce ADW Pocket Guides!</p> <p> <a href="/news/5009059054038197651/">Read more...</a> </p> </div> <h2 class="offscreen">Search</h2> <div id="site-search"> <form action="/search" method="GET"> <label for="q" class="offscreen">Enter search text</label> <input value="" id="q" name="q" class="span12" size="15" type="text" placeholder="Search ADW" /> <button class="btn"> <i class="icon-zoom-in"></i> <span class="offscreen">Search</span> </button> <p style="max-height: 35px"> <label for="feature-list" class="offscreen">Search in feature</label> <select size="1" name="feature" class="feature-list input-medium" id="feature-list"> <option value="INFORMATION">Taxon Information</option> <option value="COLLECTIONS">Contributor Galleries</option> <option value="TOPICS">Topics</option> <option value="CLASSIFICATION">Classification</option> </select> </p> </form> <ul class="unstyled"> <li> <a href="https://animaldiversity.ummz.umich.edu/quaardvark/">Explore Data @ Quaardvark</a> </li> <li> <a href="/search_guide/">Search Guide</a> </li> </ul> </div> <h2 class="offscreen">Navigation Links</h2> <dl class="tabbed features"> <dd class="feature-information active"> <a name="feature-information" href="/accounts/Platyhelminthes/" class="active" id="feature-information"> Information </a> </dd> <dd class="feature-pictures"> <a name="feature-pictures" href="/accounts/Platyhelminthes/pictures/" id="feature-pictures"> Pictures </a> </dd> <dd class="feature-specimens"> <a name="feature-specimens" href="/accounts/Platyhelminthes/specimens/" id="feature-specimens"> Specimens </a> </dd> <dd class="feature-classification"> <a name="feature-classification" href="/accounts/Platyhelminthes/classification/#Platyhelminthes" id="feature-classification"> Classification </a> </dd> </dl> <div class="classification well"> <h3>Classification</h3> <ul class="unstyled"> <li> <span class="rank">Kingdom</span> <a href="/accounts/Animalia/" class="taxon-name rank-kingdom">Animalia</a> <span class="vernacular-name">animals</span> <div class="features"> <a href="/accounts/Animalia/" class="feature feature-information" rel="tooltip" data-original-title="Animalia: information (1)" data-delay="250" data-total="4749">Animalia: information (1)</a> <a href="/accounts/Animalia/pictures/" class="feature feature-pictures" rel="tooltip" data-original-title="Animalia: pictures (22861)" data-delay="250">Animalia: pictures (22861)</a> <a href="/accounts/Animalia/specimens/" class="feature feature-specimens" rel="tooltip" data-original-title="Animalia: specimens (7109)" data-delay="250">Animalia: specimens (7109)</a> <a href="/accounts/Animalia/sounds/" class="feature feature-sounds" rel="tooltip" data-original-title="Animalia: sounds (722)" data-delay="250">Animalia: sounds (722)</a> <a href="/accounts/Animalia/maps/" class="feature feature-maps" rel="tooltip" data-original-title="Animalia: maps (42)" data-delay="250">Animalia: maps (42)</a> </div> </li> <li class="active"> <span class="rank">Unspecified</span> <a href="/accounts/Platyhelminthes/" class="taxon-name rank-unspecified">Platyhelminthes</a> <span class="vernacular-name">flatworms</span> <div class="features"> <a href="/accounts/Platyhelminthes/" class="feature feature-information" rel="tooltip" data-original-title="Platyhelminthes: information (1)" data-delay="250" data-total="40">Platyhelminthes: information (1)</a> <a href="/accounts/Platyhelminthes/pictures/" class="feature feature-pictures" rel="tooltip" data-original-title="Platyhelminthes: pictures (31)" data-delay="250">Platyhelminthes: pictures (31)</a> <a href="/accounts/Platyhelminthes/specimens/" class="feature feature-specimens" rel="tooltip" data-original-title="Platyhelminthes: specimens (4)" data-delay="250">Platyhelminthes: specimens (4)</a> <span class="feature-off feature-sounds"></span> <span class="feature-off feature-maps"></span> </div> </li> </ul> </div> <div class="related navlist well"> <h3>Related Taxa</h3> <ul class="descendants classification unstyled"> <li> <span class="rank">Class</span> <a href="/accounts/Cestoda/" class="taxon-name rank-class">Cestoda</a> <span class="vernacular-name"></span> <div class="features"> <a href="/accounts/Cestoda/" class="feature feature-information" rel="tooltip" data-original-title="Cestoda: information (1)" data-delay="250" data-total="11">Cestoda: information (1)</a> <a href="/accounts/Cestoda/pictures/" class="feature feature-pictures" rel="tooltip" data-original-title="Cestoda: pictures (6)" data-delay="250">Cestoda: pictures (6)</a> <span class="feature-off feature-specimens"></span> <span class="feature-off feature-sounds"></span> <span class="feature-off feature-maps"></span> </div> </li> <li> <span class="rank">Species</span> <a href="/accounts/Moniezia_expansa/" class="taxon-name rank-species">Moniezia expansa</a> <span class="vernacular-name"></span> <div class="features"> <a href="/accounts/Moniezia_expansa/" class="feature feature-information" rel="tooltip" data-original-title="Moniezia expansa: information (1)" data-delay="250" data-total="1">Moniezia expansa: information (1)</a> <span class="feature-off feature-pictures"></span> <span class="feature-off feature-specimens"></span> <span class="feature-off feature-sounds"></span> <span class="feature-off feature-maps"></span> </div> </li> <li> <span class="rank">Class</span> <a href="/accounts/Trematoda/" class="taxon-name rank-class">Trematoda</a> <span class="vernacular-name"></span> <div class="features"> <a href="/accounts/Trematoda/" class="feature feature-information" rel="tooltip" data-original-title="Trematoda: information (1)" data-delay="250" data-total="25">Trematoda: information (1)</a> <a href="/accounts/Trematoda/pictures/" class="feature feature-pictures" rel="tooltip" data-original-title="Trematoda: pictures (17)" data-delay="250">Trematoda: pictures (17)</a> <span class="feature-off feature-specimens"></span> <span class="feature-off feature-sounds"></span> <span class="feature-off feature-maps"></span> </div> </li> <li> <span class="rank">Class</span> <a href="/accounts/Turbellaria/" class="taxon-name rank-class">Turbellaria</a> <span class="vernacular-name"></span> <div class="features"> <a href="/accounts/Turbellaria/" class="feature feature-information" rel="tooltip" data-original-title="Turbellaria: information (1)" data-delay="250" data-total="2">Turbellaria: information (1)</a> <a href="/accounts/Turbellaria/pictures/" class="feature feature-pictures" rel="tooltip" data-original-title="Turbellaria: pictures (7)" data-delay="250">Turbellaria: pictures (7)</a> <a href="/accounts/Turbellaria/specimens/" class="feature feature-specimens" rel="tooltip" data-original-title="Turbellaria: specimens (3)" data-delay="250">Turbellaria: specimens (3)</a> <span class="feature-off feature-sounds"></span> <span class="feature-off feature-maps"></span> </div> </li> </ul> </div> </div> </div> </div> </div> <div id="footer" aria-role="contentinfo"> <div class="inner-footer"> <div class="page-citation"> <p class="content">To cite this page: Myers, P. 2002. "Platyhelminthes" (On-line), Animal Diversity Web. Accessed November 24, 2024 at https://animaldiversity.org/accounts/Platyhelminthes/</p> </div> <div class="disclaimer"> <p class="content"><strong>Disclaimer:</strong> The Animal Diversity Web is an educational resource <strong>written largely by and for college students</strong>. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control. </p> </div> <div class="footer-links"> <ul class="unstyled"> <li><a href="https://www.umich.edu/">U-M Gateway</a> | <a href="https://lsa.umich.edu/ummz/">U-M Museum of Zoology</a></li> <li> <a href="https://lsa.umich.edu/eeb/">U-M Ecology and Evolutionary Biology</a> </li> <li> 漏 2020 Regents of the University of Michigan </li> <li><a href="/feedback/error_form/">Report Error</a> / <a href="/feedback/comment_form/">Comment</a></li> </ul> </div> <div class="thanks-links"> <p>This material is based upon work supported by the <a href="https://nsf.gov">National Science Foundation</a> Grants DRL 0089283, DRL 0628151, DUE 0633095, DRL 0918590, and DUE 1122742. Additional support has come from the Marisla Foundation, UM College of Literature, Science, and the Arts, Museum of Zoology, and Information and Technology Services. </p> <p> The ADW Team gratefully acknowledges their support. </p> </div> </div> </div> <script></script> </div> <script src="/static/js/jquery.colorbox.js"></script> <script src="/static/js/pica.information.js"></script> <script type="text/javascript"> var gaJsHost = (("https:" == document.location.protocol) ? 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ADW: Platyhelminthes: INFORMATION