{"id":5961,"date":"2013-12-16T08:00:21","date_gmt":"2013-12-16T07:00:21","guid":{"rendered":"http:\/\/codexvirtualis.fr\/codex\/?p=5961"},"modified":"2013-12-12T21:12:37","modified_gmt":"2013-12-12T20:12:37","slug":"semaine-51-2013","status":"publish","type":"post","link":"https:\/\/codexvirtualis.fr\/codex\/semaine-51-2013","title":{"rendered":"Semaine 51-2013"},"content":{"rendered":"<h2>Une citation<\/h2>\n<p>\u00ab\u00a0Il ne faut point juger des hommes par ce qu&rsquo;ils ignorent, mais par ce qu&rsquo;ils savent et par la mani\u00e8re dont ils le savent.\u00a0\u00bb<\/p>\n<p>Marquis de Vauvenargues<\/p>\n<p> &nbsp; <\/p>\n<h2>Une image<\/h2>\n<figure style=\"width: 300px\" class=\"wp-caption alignnone\"><a rel=\"lightbox\" href=\"https:\/\/i0.wp.com\/www.codexvirtualis.fr\/documents\/images\/Patella_pellucida_02_11-WEB.JPG\" target=\"_blank\"><img data-recalc-dims=\"1\" decoding=\"async\" class=\" \" title=\"Helcion\" src=\"https:\/\/i0.wp.com\/www.codexvirtualis.fr\/documents\/images\/Patella_pellucida_02_11-WEB.JPG?w=300\" alt=\"Helcion\"  \/><\/a><figcaption class=\"wp-caption-text\">Helcion (Carantec, f\u00e9vrier 2011)<\/figcaption><\/figure>\n<p> &nbsp; <\/p>\n<p>L&rsquo;Helcion (<em>Patella pellucida<\/em>) est un Mollusque Gast\u00e9ropode de la famille des Patellid\u00e9s.<\/p>\n<p>L&rsquo;<a href=\"\/codex\/glossaire\/glossaire-de-a-a-c#adulte\" target=\"_blank\">adulte<\/a> vit sur les laminaires, grandes algues brunes pr\u00e9sentes dans la zone du littoral soumise \u00e0 une alternance d&rsquo;immersions et \u00e9mersions due aux mar\u00e9es (zone de balancement des mar\u00e9es ou zone intertidale) et la frange de c\u00f4te toujours immerg\u00e9e qui la borde (zone infralittorale).<\/p>\n<p> &nbsp; <\/p>\n<p>L&rsquo;Helcion est ais\u00e9ment identifi\u00e9 \u00e0 la forme et aux couleurs de sa coquille.<\/p>\n<p>Ovale et relativement aplatie, elle a une longueur de 20 mm au maximum. <\/p>\n<p>De teinte brune, elle est lisse, translucide et orn\u00e9e de bandes longitudinales discontinues. Celles du centre sont d&rsquo;une couleur bleue dont les reflets m\u00e9talliques sont remarquables.<\/p>\n<p> &nbsp; <\/p>\n<p>L&rsquo;Helcion adulte se nourrit de laminaires, dont il broute les tissus \u00e0 l&rsquo;aide d&rsquo;un ruban h\u00e9riss\u00e9 de dents associ\u00e9 \u00e0 sa bouche, appel\u00e9 radula.<\/p>\n<p>Les mouvements de va-et-vient de la radula d\u00e9tachent de l&rsquo;algue de petites particules que l&rsquo;animal avale, creusant progressivement une d\u00e9pression \u00e0 sa surface.<\/p>\n<p>Les individus jeunes ing\u00e8rent pour leur part les algues microscopiques pr\u00e9sentes sur les laminaires, qu&rsquo;ils pr\u00e9l\u00e8vent de la m\u00eame mani\u00e8re.<\/p>\n<p> &nbsp; <\/p>\n<p>La reproduction des Helcions intervient en hiver et au printemps.<\/p>\n<p>La femelle d\u00e9pose des ovules sur les algues, et le m\u00e2le r\u00e9pand des spermatozo\u00efdes \u00e0 leur contact.<\/p>\n<p>La f\u00e9condation conduit \u00e0 la formation d&rsquo;<a href=\"\/codex\/glossaire\/glossaire-de-i-a-o#oeuf\" target=\"_blank\">\u0153ufs<\/a> que la mer emporte.<\/p>\n<p>Le <a href=\"\/codex\/glossaire\/glossaire-de-d-a-h#developpement-embryonnaire\" target=\"_blank\">d\u00e9veloppement embryonnaire<\/a> dure quelques semaines et \u00e0 son terme, en mai, l&rsquo;\u00e9closion lib\u00e8re des <a href=\"\/codex\/glossaire\/glossaire-de-i-a-o#larve\" target=\"_blank\">larves<\/a> qui \u00e9voluent dans le plancton.<\/p>\n<p>Le <a href=\"\/codex\/glossaire\/glossaire-de-d-a-h#developpement-post-embryonnaire\" target=\"_blank\">d\u00e9veloppement post-embryonnaire<\/a> implique une <a href=\"\/codex\/glossaire\/glossaire-de-i-a-o#metamorphose\" target=\"_blank\">m\u00e9tamorphose<\/a> qui transforme la larve en <a href=\"\/codex\/glossaire\/glossaire-de-i-a-o#juvenile\" target=\"_blank\">juv\u00e9nile<\/a> vivant sur le substrat.<br \/>\nCelui-ci se d\u00e9place jusqu&rsquo;\u00e0 trouver une laminaire sur laquelle il s&rsquo;installe.<\/p>\n<p>\u00c0 l&rsquo;automne, il acquiert la maturit\u00e9 sexuelle et devient adulte.<\/p>\n<p> &nbsp; <\/p>\n<p>Pour en savoir plus, consulter :<\/p>\n<p><span style=\"color: #999999;\">&bull; <\/span>le site <a href=\"http:\/\/doris.ffessm.fr\" target=\"_blank\">Doris<\/a> (Donn\u00e9es d&rsquo;observations pour la reconnaissance et l&rsquo;identification de la faune et de la flore subaquatiques &#8211; F\u00e9d\u00e9ration fran\u00e7aise d&rsquo;\u00e9tudes et de sports sous-marins &#8211; adresse : http:\/\/doris.ffessm.fr)<\/p>\n<p>et notamment<\/p>\n<p><span style=\"color: #999999;\">&bull; <\/span>la fiche <a href=\"http:\/\/doris.ffessm.fr\/fiche2.asp?fiche_numero=792\" target=\"_blank\">ZIEMSKI Fr\u00e9d\u00e9ric, M\u00dcLLER Yves,  in : DORIS, 19\/4\/2012 : Patella pellucida Linnaeus 1758<\/a> (adresse : http:\/\/doris.ffessm.fr\/fiche2.asp?fiche_numero=792)<\/p>\n<p> &nbsp; <\/p>\n<hr \/>\n","protected":false},"excerpt":{"rendered":"<p>Une citation \u00ab\u00a0Il ne faut point juger des hommes par ce qu&rsquo;ils ignorent, mais par ce qu&rsquo;ils savent et par la mani\u00e8re dont ils le savent.\u00a0\u00bb Marquis de Vauvenargues &nbsp; Une image &nbsp; L&rsquo;Helcion (Patella pellucida) est un Mollusque Gast\u00e9ropode de la famille des Patellid\u00e9s. L&rsquo;adulte vit sur les laminaires, grandes algues brunes pr\u00e9sentes dans [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[1],"tags":[28,12,23],"class_list":["post-5961","post","type-post","status-publish","format-standard","hentry","category-a-la-une","tag-biologie","tag-mollusque","tag-observation"],"aioseo_notices":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/posts\/5961","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/comments?post=5961"}],"version-history":[{"count":16,"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/posts\/5961\/revisions"}],"predecessor-version":[{"id":6004,"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/posts\/5961\/revisions\/6004"}],"wp:attachment":[{"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/media?parent=5961"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/categories?post=5961"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/tags?post=5961"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}