{"id":14838,"date":"2020-09-05T15:25:34","date_gmt":"2020-09-05T15:25:34","guid":{"rendered":"https:\/\/www.lifescienceart.com\/?p=14838"},"modified":"2020-09-05T15:25:34","modified_gmt":"2020-09-05T15:25:34","slug":"do-sharks-sleep-and-if-so-how","status":"publish","type":"post","link":"https:\/\/www.lifescienceart.com\/cs\/science\/zoology\/do-sharks-sleep-and-if-so-how\/","title":{"rendered":"Sp\u00ed \u017eraloci? Nov\u00e1 studie odhaluje p\u0159ekvapivou pravdu"},"content":{"rendered":"<h2 class=\"wp-block-heading\">Sp\u00ed \u017eraloci, a pokud ano, jak?<\/h2>\n\n<h2 class=\"wp-block-heading\">Metabolismus a dr\u017een\u00ed t\u011bla odhaluj\u00ed sp\u00e1nek u \u017eralok\u016f<\/h2>\n\n<p>Po stalet\u00ed v\u011bdci vedli debaty o tom, zda \u017eraloci sp\u00ed. N\u011bkter\u00e9 druhy, jako jsou \u017eraloci b\u00edl\u00ed a tyg\u0159\u00ed, mus\u00ed neust\u00e1le plavat, aby zajistili proud\u011bn\u00ed okysli\u010den\u00e9 vody p\u0159es sv\u00e9 \u017e\u00e1bra. To vedlo k p\u0159esv\u011bd\u010den\u00ed, \u017ee \u017eraloci v\u016fbec nesp\u00ed.<\/p>\n\n<p>Nicm\u00e9n\u011b ned\u00e1vn\u00fd v\u00fdzkum tento dlouho tradovan\u00fd p\u0159edpoklad vyvr\u00e1til. V\u011bdci v Austr\u00e1lii zdokumentovali, jak druh \u017eraloka \u017eij\u00edc\u00edho u dna, \u017eralok \u0161achovnicov\u00fd, poprv\u00e9 sp\u00ed.<\/p>\n\n<p>Na rozd\u00edl od \u017eralok\u016f b\u00edl\u00fdch a tyg\u0159\u00edch jsou \u017eraloci \u0161achovnicov\u00ed tzv. buk\u00e1ln\u00ed pumpuj\u00edc\u00ed \u017eraloci. To znamen\u00e1, \u017ee mohou ru\u010dn\u011b vh\u00e1n\u011bt vodu p\u0159es sv\u00e9 \u017e\u00e1bra, aby p\u0159ij\u00edmali kysl\u00edk, zat\u00edmco z\u016fst\u00e1vaj\u00ed nehybn\u00ed.<\/p>\n\n<p>Aby v\u00fdzkumn\u00fd t\u00fdm zjistil, zda \u017eraloci \u0161achovnicov\u00ed skute\u010dn\u011b sp\u00ed, analyzoval jejich metabolismus a dr\u017een\u00ed t\u011bla po dobu 24 hodin. Zjistili, \u017ee kdy\u017e \u017eraloci odpo\u010d\u00edvali po dobu p\u011bti minut nebo d\u00e9le, jejich spot\u0159eba kysl\u00edku v\u00fdrazn\u011b klesla, co\u017e nazna\u010dovalo, \u017ee upadali do sp\u00e1nku.<\/p>\n\n<p>Krom\u011b poklesu metabolismu pozorovali v\u011bdci tak\u00e9 zm\u011bny v dr\u017een\u00ed t\u011bla \u017eralok\u016f. Kdy\u017e spali, \u017eraloci zplo\u0161tili sv\u00e1 t\u011bla a p\u0159itiskli se bl\u00ed\u017ee k zemi.<\/p>\n\n<h2 class=\"wp-block-heading\">Zav\u0159en\u00e9 o\u010di a sv\u011btlo<\/h2>\n\n<p>Zaj\u00edmav\u00e9 je, \u017ee v\u011bdci zjistili, \u017ee \u017eraloci \u0161achovnicov\u00ed n\u011bkdy spali se zav\u0159en\u00fdma o\u010dima, ale v\u011bt\u0161inou p\u0159es den. V noci se \u010dast\u011bji rozhodli nech\u00e1vat o\u010di otev\u0159en\u00e9.<\/p>\n\n<p>To vedlo v\u011bdce k podez\u0159en\u00ed, \u017ee zav\u00edr\u00e1n\u00ed o\u010d\u00ed u \u017eralok\u016f m\u016f\u017ee m\u00edt v\u00edce spole\u010dn\u00e9ho se sv\u011btlem ne\u017e se samotn\u00fdm sp\u00e1nkem. P\u0159ibli\u017en\u011b 38 % \u017eralok\u016f nechalo v noci o\u010di otev\u0159en\u00e9, i kdy\u017e vypadali, \u017ee sp\u00ed.<\/p>\n\n<h2 class=\"wp-block-heading\">D\u016fkazy sp\u00e1nku u \u017eralok\u016f<\/h2>\n\n<p>Kombinace poklesu metabolismu, zm\u011bn v dr\u017een\u00ed t\u011bla a sn\u00ed\u017een\u00e9 reakce na podn\u011bty poskytuje siln\u00e9 d\u016fkazy o tom, \u017ee \u017eraloci \u0161achovnicov\u00ed skute\u010dn\u011b sp\u00ed.<\/p>\n\n<p>Tento objev je v\u00fdznamn\u00fd, proto\u017ee zpochyb\u0148uje dlouho tradovanou v\u00edru, \u017ee \u017eraloci nesp\u00ed. Poskytuje tak\u00e9 nov\u00e9 poznatky o evoluci sp\u00e1nku, proto\u017ee \u017eraloci jsou nejstar\u0161\u00ed \u017eij\u00edc\u00ed \u010delistnat\u00ed obratlovci.<\/p>\n\n<h2 class=\"wp-block-heading\">Budouc\u00ed v\u00fdzkum<\/h2>\n\n<p>V\u00fdzkumn\u00fd t\u00fdm pl\u00e1nuje prov\u00e9st dal\u0161\u00ed studie, aby prozkoumal sp\u00e1nek u dal\u0161\u00edch druh\u016f \u017eralok\u016f. Pl\u00e1nuj\u00ed tak\u00e9 analyzovat mozkovou aktivitu \u017eralok\u016f, zat\u00edmco sp\u00ed, aby se dozv\u011bd\u011bli v\u00edce o jejich stavech bd\u011blosti a odpo\u010dinku.<\/p>\n\n<p>Pochopen\u00ed toho, jak a pro\u010d \u017eraloci sp\u00ed, poskytne d\u016fle\u017eit\u00e9 poznatky o funkci sp\u00e1nku a o tom, jak se vyv\u00edjel v pr\u016fb\u011bhu \u010dasu.<\/p>\n\n<h2 class=\"wp-block-heading\">Dal\u0161\u00ed informace<\/h2>\n\n<ul class=\"wp-block-list\">\n<li>\u017draloci \u0161achovnicov\u00ed jsou dravci z utajen\u00ed, kte\u0159\u00ed obvykle lov\u00ed v noci.<\/li>\n<li>Pou\u017e\u00edvaj\u00ed sv\u00e9 maskov\u00e1n\u00ed, aby splynuli s mo\u0159sk\u00fdm dnem, a \u010dekaj\u00ed, a\u017e se ko\u0159ist p\u0159ibl\u00ed\u017e\u00ed.<\/li>\n<li>\u017draloci \u0161achovnicov\u00ed se vyskytuj\u00ed v pob\u0159e\u017en\u00edch vod\u00e1ch kolem Nov\u00e9ho Z\u00e9landu.<\/li>\n<li>Jsou relativn\u011b mal\u00ed a dosahuj\u00ed maxim\u00e1ln\u00ed d\u00e9lky asi t\u0159i stopy.<\/li>\n<li>\u017draloci \u0161achovnicov\u00ed nejsou pova\u017eov\u00e1ni za hrozbu pro \u010dlov\u011bka.<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>Sp\u00ed \u017eraloci, a pokud ano, jak? Metabolismus a dr\u017een\u00ed t\u011bla odhaluj\u00ed sp\u00e1nek u \u017eralok\u016f Po stalet\u00ed v\u011bdci vedli debaty o tom, zda \u017eraloci sp\u00ed. N\u011bkter\u00e9 druhy, jako jsou \u017eraloci b\u00edl\u00ed&hellip;<\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[280],"tags":[309,136,361,888,73],"class_list":["post-14838","post","type-post","status-publish","format-standard","hentry","category-zoology","tag-animal-behavior","tag-evolution","tag-marine-biology","tag-sleep","tag-sharks"],"_links":{"self":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/14838","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/comments?post=14838"}],"version-history":[{"count":1,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/14838\/revisions"}],"predecessor-version":[{"id":14839,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/14838\/revisions\/14839"}],"wp:attachment":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/media?parent=14838"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/categories?post=14838"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/tags?post=14838"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}