{"id":537,"date":"2019-01-05T16:29:22","date_gmt":"2019-01-05T15:29:22","guid":{"rendered":"https:\/\/vidamarina.info\/?p=537"},"modified":"2019-02-07T20:43:54","modified_gmt":"2019-02-07T19:43:54","slug":"barquetes-de-sant-pere-bloom-a-la-costa-catalana","status":"publish","type":"post","link":"https:\/\/vidamarina.info\/?p=537","title":{"rendered":"Barquetes de Sant Pere, \u00abBloom\u00bb a la costa catalana"},"content":{"rendered":"<p><strong>per Carlos Bailo i Manuel Ballesteros<\/strong><\/p>\n<h4>Introducci\u00f3<\/h4>\n<p>A finals del mes d&#8217;abril del 2018, es va observar un dels fen\u00f2mens m\u00e9s estranys de l&#8217;oce\u00e0: una gran onada de Barquetes de Sant Pere o velers (Velella velella) van arribar al litoral (Figura 1). Aquests organismes van tenyir les platges del litoral catal\u00e0 de color blau i van inquietar a molts banyistes davant la pregunta de si eren perillosos. Per sort, es tracten de col\u00f2nies de p\u00f2lips, la picada dels quals no \u00e9s dolorosa pels humans, tot i que s&#8217;ha d&#8217;anar amb compte, ja que despr\u00e9s de manipular-la si ens toquem els ulls pot causar irritaci\u00f3 en ells.<\/p>\n<div id=\"attachment_547\" style=\"width: 910px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/vidamarina.info\/?attachment_id=547\" rel=\"attachment wp-att-547\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-547\" data-attachment-id=\"547\" data-permalink=\"https:\/\/vidamarina.info\/?attachment_id=547\" data-orig-file=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/figura1.jpg?fit=1920%2C720&amp;ssl=1\" data-orig-size=\"1920,720\" data-comments-opened=\"1\" data-image-title=\"Figura 1: Acumulaci\u00f3 de barquetes de Sant Pere (Velella velella)  al llarg de la costa de Badalona\" data-image-description=\"&lt;p&gt;Figura 1: Acumulaci\u00f3 de barquetes de Sant Pere (Velella velella)  al llarg de la costa de Badalona, Catalunya, Espanya&lt;\/p&gt;\n\" data-image-caption=\"&lt;p&gt;Figura 1: Acumulaci\u00f3 de barquetes de Sant Pere (Velella velella)  al llarg de la costa de Badalona, Catalunya, Espanya.&lt;br \/&gt;Fotos C. Bailo&lt;\/p&gt;\n\" data-large-file=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/figura1.jpg?fit=900%2C338&amp;ssl=1\" class=\"size-large wp-image-547\" src=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/figura1.jpg?resize=900%2C338&#038;ssl=1\" alt=\"Figura 1: Acumulaci\u00f3 de barquetes de Sant Pere (Velella velella) al llarg de la costa de Badalona, Catalunya, Espanya. Fotos C. Bailo\" width=\"900\" height=\"338\" srcset=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/figura1.jpg?resize=1024%2C384&amp;ssl=1 1024w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/figura1.jpg?resize=300%2C113&amp;ssl=1 300w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/figura1.jpg?resize=768%2C288&amp;ssl=1 768w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/figura1.jpg?resize=150%2C56&amp;ssl=1 150w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/figura1.jpg?w=1920&amp;ssl=1 1920w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/figura1.jpg?w=1800&amp;ssl=1 1800w\" sizes=\"auto, (max-width: 900px) 100vw, 900px\" \/><\/a><p id=\"caption-attachment-547\" class=\"wp-caption-text\">Figura 1: Acumulaci\u00f3 de barquetes de Sant Pere (Velella velella) al llarg de la costa de Badalona.<\/p><\/div>\n<h4>Taxonomia de <em>Velella velella<\/em><\/h4>\n<p>A continuaci\u00f3 s&#8217;indica la taxonomia completa de la barqueta de Sant Pere, segons el WoRMS:<\/p>\n<ul>\n<li>Regne Animalia\n<ul>\n<li>Filum Cnidaria Verrill, 1865\n<ul>\n<li>Classe Hydrozoa Owen, 1843\n<ul>\n<li>Subclasse Hydroidolina Collins, 2000\n<ul>\n<li>Ordre Anthoathecata Cornelius, 1992\n<ul>\n<li>Subordre Capitata K\u00fchn, 1913\n<ul>\n<li>Familia Porpitidae Goldfuss, 1818\n<ul>\n<li>G\u00e8nere <em>Velella<\/em> Lamarck, 1801\n<ul>\n<li>Esp\u00e8cie <em>Velella velella<\/em> (Linnaeus, 1758)<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h4>Qui \u00e9s la <em>Velella velella<\/em> ?<\/h4>\n<p>Tot i que pot semblar una medusa, es tracta d&#8217;una col\u00f2nia p\u00f2lips del F\u00edlum Cnidaria. En general cada col\u00f2nia mesura menys de 7 cent\u00edmetres de llarg, i la base \u00e9s d&#8217;un color blau intens degut als p\u00f2lips. Aquest organisme flota a la superf\u00edcie del mar, i est\u00e0 format (Figura 2) per una base ovalada (flotador) amb c\u00e0meres d\u00b4aire de forma circular amb porus, una vela triangular a la part superior i una col\u00f2nia de p\u00f2lips a la part inferior. Entre els p\u00f2lips hi ha un que alimenta a la col\u00f2nia (<em>gastrozo\u00efdes<\/em>), altres que tenen missi\u00f3 reproductora (<em>gonozo\u00efdes<\/em>) i altres de missi\u00f3 defensiva (<em>dactilozo\u00efdes<\/em>).<\/p>\n<div id=\"attachment_531\" style=\"width: 650px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/vidamarina.info\/?attachment_id=531\" rel=\"attachment wp-att-531\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-531\" data-attachment-id=\"531\" data-permalink=\"https:\/\/vidamarina.info\/?attachment_id=531\" data-orig-file=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image005.jpg?fit=640%2C461&amp;ssl=1\" data-orig-size=\"640,461\" data-comments-opened=\"1\" data-image-title=\"image005\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image005.jpg?fit=640%2C461&amp;ssl=1\" class=\"wp-image-531 size-full\" src=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image005.jpg?resize=640%2C461&#038;ssl=1\" alt=\"Estructura d\u00b4una barqueta de Sant Pere\" width=\"640\" height=\"461\" srcset=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image005.jpg?w=640&amp;ssl=1 640w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image005.jpg?resize=300%2C216&amp;ssl=1 300w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image005.jpg?resize=150%2C108&amp;ssl=1 150w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/a><p id=\"caption-attachment-531\" class=\"wp-caption-text\">Figura 2. Estructura d\u00b4una barqueta de Sant Pere (<em>Velella velella<\/em>)<br \/>(modificada segons <a href=\"http:\/\/cronodon.com\/BioTech\/Jellyfish2.html\">http:\/\/cronodon.com\/BioTech\/Jellyfish2.html<\/a> )<\/p><\/div>\n<p>La barqueta de Sant Pere \u00e9s carn\u00edvora i s\u2019alimenta generalment del zoopl\u00e0ncton que atrapa amb els tentacles dels p\u00f2lips defensius. Com tots els cnidaris, posseeixen <em>cnidocists<\/em> (c\u00e8l\u00b7lules urticants especialitzades en defensa i depredaci\u00f3), en principi benignes per als humans. S\u2019ha de tenir en compte que cada persona pot respondre de manera diferent davant les toxines d\u2019aquests organismes, per tant, \u00e9s recomanable no tocar-los.<\/p>\n<h4>H\u00e0bitat, cicle vital i el per qu\u00e8 del \u00abbloom\u00bb<\/h4>\n<p><em>Velella velella <\/em>t\u00e9 una distribuci\u00f3 global en aig\u00fces c\u00e0lides i temperades dels diferents mars i oceans. Viu en la interfase entre aire, mitjan\u00e7ant la vela, i aigua, amb els p\u00f2lips; llavors forma part del anomenat <strong>pl\u00e8uston<\/strong>. El seu mitj\u00e0 de locomoci\u00f3 \u00e9s la vela, la qual s\u2019alinea amb la direcci\u00f3 del vent actuant com a tim\u00f3. Per aquest motiu la <em>Velella velella<\/em> dep\u00e8n completament del vent per despla\u00e7ar-se i a conseq\u00fc\u00e8ncia de vents constants i els corrents marins poden formar grans congregacions al mar i finalment quedar varades a les costes.<\/p>\n<p>Es dona la circumst\u00e0ncia que al estar la vela un mica en diagonal a la base ovalada de la col\u00f2nia, quan bufa el vent i segons la posici\u00f3 de les col\u00f2nies, unes es dirigeixen cap al nord i altres cap el sud, formant dues agregacions de col\u00f2nies ben definides. \u00c9s per aquest motiu pel qual \u201cl\u00b4invasi\u00f3\u201d de <em>Velella velella<\/em> a les costes es pot produir en una gran extensi\u00f3 de zona costanera (a Catalunya el 2018 van avarar des de la Costa Brava fins a la costa del Barcelon\u00e8s i de Tarragona).<\/p>\n<p><em>Velella velella<\/em> t\u00e9 un cicle vital en dues fases, la de p\u00f2lip i la de medusa, amb alternan\u00e7a de generacions, la asexual i la sexual (Figura 3).<\/p>\n<div id=\"attachment_532\" style=\"width: 485px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/vidamarina.info\/?attachment_id=532\" rel=\"attachment wp-att-532\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-532\" data-attachment-id=\"532\" data-permalink=\"https:\/\/vidamarina.info\/?attachment_id=532\" data-orig-file=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image007.png?fit=475%2C318&amp;ssl=1\" data-orig-size=\"475,318\" data-comments-opened=\"1\" data-image-title=\"Figura 3: Cicle vital de Vellella velella\" data-image-description=\"&lt;p&gt;Figura 3: Cicle vital de Vellella velella&lt;\/p&gt;\n\" data-image-caption=\"&lt;p&gt;Figura 3: Cicle vital de Vellella velella&lt;\/p&gt;\n\" data-large-file=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image007.png?fit=475%2C318&amp;ssl=1\" class=\"size-full wp-image-532\" src=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image007.png?resize=475%2C318&#038;ssl=1\" alt=\"Figura 3: Cicle vital de Vellella velella\" width=\"475\" height=\"318\" srcset=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image007.png?w=475&amp;ssl=1 475w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image007.png?resize=300%2C201&amp;ssl=1 300w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image007.png?resize=150%2C100&amp;ssl=1 150w\" sizes=\"auto, (max-width: 475px) 100vw, 475px\" \/><\/a><p id=\"caption-attachment-532\" class=\"wp-caption-text\">Figura 3: Cicle vital de <em>Vellella velella<\/em><\/p><\/div>\n<p>Els exemplars que apareixen a les platges estan en la fase p\u00f2lip del seu cicle vital. Cada veler \u00e9s en realitat una col\u00f2nia de molts p\u00f2lips que estan connectats per un sistema de canals (<em>solenis<\/em>) que els hi permet compartir el menjar que capturen els dactilozo\u00efdes i digereix el gastrozo\u00efde. Els p\u00f2lips reproductors o gonozo\u00efdes produeixen, mitjan\u00e7ant gemmaci\u00f3, nombroses i diminutes meduses d&#8217;1 mm que tenen vida lliure al pl\u00e0ncton. Aquestes meduses maduren sexualment i emeten g\u00e0metes a l&#8217;aigua que, quan es fecunden, originen unes larves anomenades <em>conaries<\/em> que finalment es transformaran en col\u00f2nies flotants de p\u00f2lips. Aquesta fase de p\u00f2lip es d\u00f3na entre els mesos de mar\u00e7 i juny, i s&#8217;observa una major quantitat d&#8217;aquests organismes entre els mesos d&#8217;abril i maig (Figura 4).<\/p>\n<div id=\"attachment_533\" style=\"width: 463px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/vidamarina.info\/?attachment_id=533\" rel=\"attachment wp-att-533\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-533\" data-attachment-id=\"533\" data-permalink=\"https:\/\/vidamarina.info\/?attachment_id=533\" data-orig-file=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image009.jpg?fit=453%2C309&amp;ssl=1\" data-orig-size=\"453,309\" data-comments-opened=\"1\" data-image-title=\"Figura 4.Observacions de Velella velella segons la estacionalitat\" data-image-description=\"&lt;p&gt;Figura 4.Observacions de Velella velella segons la estacionalitat&lt;\/p&gt;\n\" data-image-caption=\"&lt;p&gt;Figura 4.Observacions de Velella velella segons la estacionalitat&lt;\/p&gt;\n\" data-large-file=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image009.jpg?fit=453%2C309&amp;ssl=1\" class=\"size-full wp-image-533\" src=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image009.jpg?resize=453%2C309&#038;ssl=1\" alt=\"Figura 4.Observacions de Velella velella segons la estacionalitat\" width=\"453\" height=\"309\" srcset=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image009.jpg?w=453&amp;ssl=1 453w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image009.jpg?resize=300%2C205&amp;ssl=1 300w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image009.jpg?resize=150%2C102&amp;ssl=1 150w\" sizes=\"auto, (max-width: 453px) 100vw, 453px\" \/><\/a><p id=\"caption-attachment-533\" class=\"wp-caption-text\">Figura 4. Observacions de <em>Velella velella<\/em> segons la estacionalitat<br \/>Font: Asturnatura.com<\/p><\/div>\n<p>Es tracta d&#8217;un fenomen que ocorre cada any, per\u00f2 l\u00b4any 2018 s\u2019ha observat un augment de la quantitat d&#8217;aquest velers a les costes catalanes, tenyint de blau les sorres de moltes platges, en all\u00f2 que anomenem un \u201cbloom\u201d de <em>Velella velella<\/em>.<\/p>\n<p>Des de l&#8217;ICM (Institut de Ci\u00e8ncies del Mar) de Barcelona informen que\u00a0 aquest fenomen (la gran quantitat de velers que han arribat a les costes Catalanes) pot ser conseq\u00fc\u00e8ncia d&#8217;una disminuci\u00f3 de la depredaci\u00f3 d&#8217;aquestes col\u00f2nies pels seus depredadors naturals o, tamb\u00e9, a l\u2019afavoriment de la direcci\u00f3 de les corrents marines degut a l&#8217;hivern fred de l&#8217;any 2018.<\/p>\n<p>Tot i aix\u00ed, tot aquell que s\u2019hagu\u00e9s acostat a les platges quan es va donar aquest fen\u00f2men, \u00e9s probable que observ\u00e9s la pres\u00e8ncia de\u00a0<em>Janthina janthina<\/em>, un cargol depredador de les barquetes de Sant Pere.<\/p>\n<div id=\"attachment_549\" style=\"width: 910px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/vidamarina.info\/?attachment_id=549\" rel=\"attachment wp-att-534\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-549\" data-attachment-id=\"549\" data-permalink=\"https:\/\/vidamarina.info\/?attachment_id=549\" data-orig-file=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image015-1.jpg?fit=900%2C652&amp;ssl=1\" data-orig-size=\"900,652\" data-comments-opened=\"1\" data-image-title=\"Figura 6: Janthina janthina depredant a les barquetes de Sant Pere (Velella velella), trobades a la costa de Badalona, Catalunya.\" data-image-description=\"&lt;p&gt;Figura 6: Janthina janthina depredant a les barquetes de Sant Pere (Velella velella), trobades a la costa de Badalona, Catalunya.&lt;\/p&gt;\n\" data-image-caption=\"&lt;p&gt;Figura 6: Janthina janthina depredant a les barquetes de Sant Pere (Velella velella), trobades a la costa de Badalona, Catalunya.&lt;BR&gt;Foto Carlos Bailo&lt;\/p&gt;\n\" data-large-file=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image015-1.jpg?fit=900%2C652&amp;ssl=1\" class=\"wp-image-549 size-full\" src=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image015-1.jpg?resize=900%2C652&#038;ssl=1\" alt=\"Figura 6: Janthina janthina depredant a les barquetes de Sant Pere (Velella velella), trobades a la costa de Badalona, Catalunya.\" width=\"900\" height=\"652\" srcset=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image015-1.jpg?w=900&amp;ssl=1 900w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image015-1.jpg?resize=300%2C217&amp;ssl=1 300w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image015-1.jpg?resize=768%2C556&amp;ssl=1 768w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image015-1.jpg?resize=150%2C109&amp;ssl=1 150w\" sizes=\"auto, (max-width: 900px) 100vw, 900px\" \/><\/a><p id=\"caption-attachment-549\" class=\"wp-caption-text\">Figura 5: <em>Janthina janthina<\/em> depredant a les barquetes de Sant Pere (<em>Velella velella<\/em>), trobades a la costa de Badalona<\/p><\/div>\n<h4>El depredador <em>Janthina janthina<\/em><\/h4>\n<p><em>El cargol violaci o Janthina janthina<\/em> (Figura 6) \u00e9s un mol\u00b7lusc completament pel\u00e0gic d\u2019uns 3 cent\u00edmetres de di\u00e0metre, amb una conquilla de color blau lil\u00f3s. \u00c9s carn\u00edvor i s\u2019alimenta d\u2019animals que floten en l\u2019aigua de mar com ara\u00a0<em>Velella velella<\/em> (Figura 5) i la caravel\u00b7la portuguesa <em>Physalia physalis<\/em>.<\/p>\n<p>Aquest cargol forma part del <strong>pl\u00e8uston<\/strong> i utilitza una estrat\u00e8gia molt interesant per flotar i arribar al seu aliment: captura aire i el tanca dins d&#8217;unes bombolles que mant\u00e9 adherides al peu i per aquest motiu viu invertit en la interfase aire \/ aigua, penjant de les bombolles d&#8217;aire amb la conquilla cap avall.<\/p>\n<div id=\"attachment_535\" style=\"width: 910px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/vidamarina.info\/?attachment_id=535\" rel=\"attachment wp-att-535\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-535\" data-attachment-id=\"535\" data-permalink=\"https:\/\/vidamarina.info\/?attachment_id=535\" data-orig-file=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image017.jpg?fit=1595%2C1400&amp;ssl=1\" data-orig-size=\"1595,1400\" data-comments-opened=\"1\" data-image-title=\"Figura 5: Janthina janthina a l\u00b4interfase aire\/aigua flotant gr\u00e0cies a les seves bombolles.\" data-image-description=\"&lt;p&gt;Figura 5: Janthina janthina a l\u00b4interfase aire\/aigua&lt;br \/&gt;\nflotant gr\u00e0cies a les seves bombolles.&lt;\/p&gt;\n\" data-image-caption=\"&lt;p&gt;Figura 5: Janthina janthina a l\u00b4interfase aire\/aigua&lt;br \/&gt;\nflotant gr\u00e0cies a les seves bombolles. Foto D. Riek (https:\/\/www.livescience.com\/16476-bubble-rafting-snail-evolution.html )&lt;\/p&gt;\n\" data-large-file=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image017.jpg?fit=900%2C790&amp;ssl=1\" class=\"size-large wp-image-535\" src=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image017.jpg?resize=900%2C790&#038;ssl=1\" alt=\"Figura 5: Janthina janthina a l\u00b4interfase aire\/aigua flotant gr\u00e0cies a les seves bombolles.\" width=\"900\" height=\"790\" srcset=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image017.jpg?resize=1024%2C899&amp;ssl=1 1024w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image017.jpg?resize=300%2C263&amp;ssl=1 300w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image017.jpg?resize=768%2C674&amp;ssl=1 768w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image017.jpg?resize=150%2C132&amp;ssl=1 150w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image017.jpg?w=1595&amp;ssl=1 1595w\" sizes=\"auto, (max-width: 900px) 100vw, 900px\" \/><\/a><p id=\"caption-attachment-535\" class=\"wp-caption-text\">Figura 6: <em>Janthina janthina<\/em> a l&#8217;interfase aire\/aigua flotant gr\u00e0cies a les seves bombolles.<br \/>Foto: D. Riek (<a href=\"https:\/\/www.livescience.com\/16476-bubble-rafting-snail-evolution.html\">https:\/\/www.livescience.com\/16476-bubble-rafting-snail-evolution.html<\/a> )<\/p><\/div>\n<p>Aquest mol\u00b7lusc es comunament observat al mes de febrer, i entre els mesos de mar\u00e7 i juny amb un pic entre els mesos d\u2019abril i maig (Figura 7) com en el cas de la <em>Velella velella<\/em>. Podr\u00edem dir que la pres\u00e8ncia les col\u00f2nies de <em>Velella velella<\/em> condicionen la pres\u00e8ncia de <em>Janthina janthina<\/em>.<\/p>\n<div id=\"attachment_536\" style=\"width: 491px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/vidamarina.info\/?attachment_id=536\" rel=\"attachment wp-att-536\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-536\" data-attachment-id=\"536\" data-permalink=\"https:\/\/vidamarina.info\/?attachment_id=536\" data-orig-file=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image019.jpg?fit=481%2C315&amp;ssl=1\" data-orig-size=\"481,315\" data-comments-opened=\"1\" data-image-title=\"Figura 7: Observacions de Janthia janthia segons la estacionalitat.\" data-image-description=\"&lt;p&gt;Figura 7: Observacions de Janthia janthia segons la estacionalitat.&lt;\/p&gt;\n\" data-image-caption=\"&lt;p&gt;Figura 7: Observacions de Janthina janthina segons la estacionalitat.&lt;\/p&gt;\n\" data-large-file=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image019.jpg?fit=481%2C315&amp;ssl=1\" class=\"size-full wp-image-536\" src=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image019.jpg?resize=481%2C315&#038;ssl=1\" alt=\"Figura 7: Observacions de Janthia janthia segons la estacionalitat.\" width=\"481\" height=\"315\" srcset=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image019.jpg?w=481&amp;ssl=1 481w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image019.jpg?resize=300%2C196&amp;ssl=1 300w, https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/image019.jpg?resize=150%2C98&amp;ssl=1 150w\" sizes=\"auto, (max-width: 481px) 100vw, 481px\" \/><\/a><p id=\"caption-attachment-536\" class=\"wp-caption-text\">Figura 7: Observacions de <em>Janthina janthina<\/em> segons la estacionalitat.<br \/>Font: Asturnatura.com<\/p><\/div>\n<p>Altres depredadors de <em>Velella velella<\/em> s\u00f3n el nudibranqui <a href=\"https:\/\/opistobranquis.info\/ca\/LcNpj\"><em>Fiona pinnata<\/em><\/a>, que viu en objectes que floten a l\u00b4aigua i varies esp\u00e8cies de tortugues marines.<\/p>\n<h4>Per con\u00e8ixer m\u00e9s&#8230;<\/h4>\n<ul>\n<li><strong>Animali blu <em>Velella velella<\/em><\/strong>. [online]<br \/>\nDisponible a: <a href=\"https:\/\/www.youtube.com\/watch?v=jtnZPyT-iic\">https:\/\/www.youtube.com\/watch?v=jtnZPyT-iic\u00a0<\/a><\/li>\n<li><strong>CCMA. (2018)<\/strong>.\u00a0<em>Meduses velella, preludi d&#8217;un estiu de meduses<\/em><span style=\"font-family: Ubuntu;\">. [online]<br \/>\nDisponible a:\u00a0<a href=\"https:\/\/www.ccma.cat\/video\/embed\/5763273\/\">https:\/\/www.ccma.cat\/video\/embed\/5763273\/<\/a><\/span><\/li>\n<li><strong>Francis, L. 1991.<\/strong> Sailing Downwind: Aerodynamic Performance of the\u00a0<em>Velella<\/em><span style=\"font-family: Ubuntu;\">\u00a0Sail. <\/span><em>Journal of Experimental Biology<\/em><span style=\"font-family: Ubuntu;\">, 158:\u00a0117-132.<\/span><\/li>\n<li><strong>Langstroth, L. &amp; Langstroth, L. 2000.<\/strong> A living bay:\u00a0 the underwater world of Monterey Bay. University of California Press, Berkeley, CA.<\/li>\n<li><strong>Monterey Bay Aquarium: the secret life of <em>Velella<\/em><\/strong><span style=\"font-family: Ubuntu;\">. [online]<br \/>\nDisponible a: <\/span><a href=\"https:\/\/www.youtube.com\/watch?v=ZJGO_bSsR3w\">https:\/\/www.youtube.com\/watch?v=ZJGO_bSsR3w<\/a><\/li>\n<li><span style=\"font-family: Ubuntu;\"><strong>AsturNatura.com<\/strong> \u00abVelella velella (Linnaeus, 1758)\u00bb. Asturnatura.com [online]. Num. 9, 07\/03\/2005 [consultat el: 5\/01\/2019]. Disponible a <a href=\"https:\/\/www.asturnatura.com\/especie\/velella-velella.html\">&lt;https:\/\/www.asturnatura.com\/especie\/velella-velella.html&gt;<\/a>. ISSN 1887-5068\u00a0<\/span><\/li>\n<li><strong>Pires RFT, Cordeiro N, Dubert J, Marraccini A, Relvas P, dos Santos A (2018)<\/strong> Untangling <em>Velella velella<\/em> (Cnidaria: Anthoathecatae) transport: a citizen science and oceanographic approach. <em>Mar Ecol Prog Ser<\/em> 591:241-251. <a href=\"https:\/\/doi.org\/10.3354\/meps12266\">https:\/\/doi.org\/10.3354\/meps12266 <\/a><\/li>\n<li><strong>Purcell, J. E., Clarkin, E. &amp; Doyle, T. K. 2012<\/strong>. Foods of\u00a0<em>Velella velella<\/em><span style=\"font-family: Ubuntu;\">\u00a0(Cnidaria: Hydrozoa) in algal rafts and its distribution in Irish seas. <\/span><a href=\"https:\/\/link.springer.com\/journal\/10750\"><em>Hydrobiologia<\/em><\/a><span style=\"font-family: Ubuntu;\">, 690 (1): 47\u201355.<\/span><\/li>\n<li><strong>WoRMS (World Register of Marine Species)<\/strong>, <em>Velella velella<\/em><span style=\"font-family: Ubuntu;\">. [online] Disponible a: <\/span><a href=\"http:\/\/www.marinespecies.org\/aphia.php?p=taxdetails&amp;id=117832\">http:\/\/www.marinespecies.org\/aphia.php?p=taxdetails&amp;id=117832<\/a><\/li>\n<\/ul>\n<div class=\"wpcp-citation-box\"><p><b>Citar este art\u00edculo como:<\/b><\/p><p class=\"citacio\"><b>Carlos Bailo, <\/b> \"Barquetes de Sant Pere, \u00abBloom\u00bb a la costa catalana\", en <em>VIMAR-Vida Marina<\/em>, publicado el 05\/01\/2019, accedido el 30\/07\/2026 en (<a href=\"https:\/\/vidamarina.info\/?p=537\">https:\/\/vidamarina.info\/?p=537<\/a>).<\/p><\/div>\n<div class=\"pvc_clear\"><\/div>\n<p id=\"pvc_stats_537\" class=\"pvc_stats all  \" data-element-id=\"537\" style=\"\"><i class=\"pvc-stats-icon medium\" aria-hidden=\"true\"><svg aria-hidden=\"true\" focusable=\"false\" data-prefix=\"far\" data-icon=\"chart-bar\" role=\"img\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewBox=\"0 0 512 512\" class=\"svg-inline--fa fa-chart-bar fa-w-16 fa-2x\"><path fill=\"currentColor\" d=\"M396.8 352h22.4c6.4 0 12.8-6.4 12.8-12.8V108.8c0-6.4-6.4-12.8-12.8-12.8h-22.4c-6.4 0-12.8 6.4-12.8 12.8v230.4c0 6.4 6.4 12.8 12.8 12.8zm-192 0h22.4c6.4 0 12.8-6.4 12.8-12.8V140.8c0-6.4-6.4-12.8-12.8-12.8h-22.4c-6.4 0-12.8 6.4-12.8 12.8v198.4c0 6.4 6.4 12.8 12.8 12.8zm96 0h22.4c6.4 0 12.8-6.4 12.8-12.8V204.8c0-6.4-6.4-12.8-12.8-12.8h-22.4c-6.4 0-12.8 6.4-12.8 12.8v134.4c0 6.4 6.4 12.8 12.8 12.8zM496 400H48V80c0-8.84-7.16-16-16-16H16C7.16 64 0 71.16 0 80v336c0 17.67 14.33 32 32 32h464c8.84 0 16-7.16 16-16v-16c0-8.84-7.16-16-16-16zm-387.2-48h22.4c6.4 0 12.8-6.4 12.8-12.8v-70.4c0-6.4-6.4-12.8-12.8-12.8h-22.4c-6.4 0-12.8 6.4-12.8 12.8v70.4c0 6.4 6.4 12.8 12.8 12.8z\" class=\"\"><\/path><\/svg><\/i> <img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"16\" height=\"16\" alt=\"Loading\" src=\"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/plugins\/page-views-count\/ajax-loader-2x.gif?resize=16%2C16&#038;ssl=1\" border=0 \/><\/p>\n<div class=\"pvc_clear\"><\/div>\n","protected":false},"excerpt":{"rendered":"<p>per Carlos Bailo i Manuel Ballesteros Introducci\u00f3 A finals del mes d&#8217;abril del 2018, es va observar un dels fen\u00f2mens m\u00e9s estranys de l&#8217;oce\u00e0: una gran onada de Barquetes de Sant Pere o velers (Velella velella) van arribar al litoral (Figura 1). Aquests organismes van tenyir les platges del litoral catal\u00e0 de color blau i van inquietar a molts banyistes&#8230;<\/p>\n<p class=\"continue-reading-button\"> <a class=\"continue-reading-link\" href=\"https:\/\/vidamarina.info\/?p=537\">Leer m\u00e1s&#8230;<i class=\"crycon-right-dir\"><\/i><\/a><\/p>\n<div class=\"pvc_clear\"><\/div>\n<p id=\"pvc_stats_537\" class=\"pvc_stats all  \" data-element-id=\"537\" style=\"\"><i class=\"pvc-stats-icon medium\" aria-hidden=\"true\"><svg aria-hidden=\"true\" focusable=\"false\" data-prefix=\"far\" data-icon=\"chart-bar\" role=\"img\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewBox=\"0 0 512 512\" class=\"svg-inline--fa fa-chart-bar fa-w-16 fa-2x\"><path fill=\"currentColor\" d=\"M396.8 352h22.4c6.4 0 12.8-6.4 12.8-12.8V108.8c0-6.4-6.4-12.8-12.8-12.8h-22.4c-6.4 0-12.8 6.4-12.8 12.8v230.4c0 6.4 6.4 12.8 12.8 12.8zm-192 0h22.4c6.4 0 12.8-6.4 12.8-12.8V140.8c0-6.4-6.4-12.8-12.8-12.8h-22.4c-6.4 0-12.8 6.4-12.8 12.8v198.4c0 6.4 6.4 12.8 12.8 12.8zm96 0h22.4c6.4 0 12.8-6.4 12.8-12.8V204.8c0-6.4-6.4-12.8-12.8-12.8h-22.4c-6.4 0-12.8 6.4-12.8 12.8v134.4c0 6.4 6.4 12.8 12.8 12.8zM496 400H48V80c0-8.84-7.16-16-16-16H16C7.16 64 0 71.16 0 80v336c0 17.67 14.33 32 32 32h464c8.84 0 16-7.16 16-16v-16c0-8.84-7.16-16-16-16zm-387.2-48h22.4c6.4 0 12.8-6.4 12.8-12.8v-70.4c0-6.4-6.4-12.8-12.8-12.8h-22.4c-6.4 0-12.8 6.4-12.8 12.8v70.4c0 6.4 6.4 12.8 12.8 12.8z\" class=\"\"><\/path><\/svg><\/i> <img loading=\"lazy\" decoding=\"async\" width=\"16\" height=\"16\" alt=\"Loading\" src=\"https:\/\/vidamarina.info\/wp-content\/plugins\/page-views-count\/ajax-loader-2x.gif\" border=0 \/><\/p>\n<div class=\"pvc_clear\"><\/div>\n","protected":false},"author":5,"featured_media":551,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[3,5],"tags":[208,211,194,195,213,212,210,191,209,55,207],"coauthors":[268,266],"class_list":["post-537","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-biologia","category-ecologia","tag-barqueta-de-sant-pere","tag-bloom","tag-catala","tag-catalan","tag-corrents","tag-costa","tag-depredador","tag-ecologia","tag-janthina","tag-taxonomia","tag-velella"],"a3_pvc":{"activated":true,"total_views":4346,"today_views":0},"jetpack_featured_media_url":"https:\/\/i0.wp.com\/vidamarina.info\/wp-content\/uploads\/2019\/01\/IMG_20180428_203919.jpg?fit=3026%2C1693&ssl=1","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/parR2S-8F","_links":{"self":[{"href":"https:\/\/vidamarina.info\/index.php?rest_route=\/wp\/v2\/posts\/537","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vidamarina.info\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vidamarina.info\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vidamarina.info\/index.php?rest_route=\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/vidamarina.info\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=537"}],"version-history":[{"count":20,"href":"https:\/\/vidamarina.info\/index.php?rest_route=\/wp\/v2\/posts\/537\/revisions"}],"predecessor-version":[{"id":987,"href":"https:\/\/vidamarina.info\/index.php?rest_route=\/wp\/v2\/posts\/537\/revisions\/987"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vidamarina.info\/index.php?rest_route=\/wp\/v2\/media\/551"}],"wp:attachment":[{"href":"https:\/\/vidamarina.info\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=537"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vidamarina.info\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=537"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vidamarina.info\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=537"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/vidamarina.info\/index.php?rest_route=%2Fwp%2Fv2%2Fcoauthors&post=537"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}