{"id":926,"date":"2016-11-25T11:50:53","date_gmt":"2016-11-25T11:50:53","guid":{"rendered":"http:\/\/natgeokids.com?p=926"},"modified":"2025-11-11T17:49:54","modified_gmt":"2025-11-11T17:49:54","slug":"drkarl","status":"publish","type":"post","link":"https:\/\/www.natgeokids.com\/au\/discover\/science\/nature\/drkarl\/","title":{"rendered":"Science with Dr Karl: Immortal Jellyfish!"},"content":{"rendered":"

<\/p>\n

\n

\"t<\/a>There have always been myths<\/a> about immortality, <\/strong>the ability to live forever. But is it possible? Well, marine biologists have found a creature that comes close \u2013 a tiny, transparent jellyfish<\/a><\/strong>.<\/p>\n

WHAT ARE THEY?<\/strong><\/p>\n

While it has the unofficial name of ‘immortal jellyfish<\/strong>‘, its official name is Turritopsis dohrnii<\/em>\u00a0<\/strong>(it used to be\u00a0Turritopsis nutricula<\/em>).<\/p>\n

After an adult male\u00a0T. dohrnii<\/em> squirts his sperm<\/strong> into the ocean waters, some of them end up inside a female. This creates fertilised eggs<\/strong>, which then turn into tiny, free-swimming larvae<\/strong> called \u201cplanula<\/strong>\u201d.<\/p>\n

\"If<\/a><\/p>\n

After a while, the planula give up swimming and dive down to the sea floor<\/strong>, where they\u00a0attach themselves to a rock<\/strong>. They then change shape entirely into columns of highly branched polyps<\/strong>. After a few days, another change of shape happens. Tiny jellyfish (about 1mm across) “bud<\/strong>\u201d off from the tips of the polyp and, like miniature umbrellas with tentacles<\/strong>, float through the ocean.<\/p>\n

After 2-4 weeks, they become sexually mature males or females. They\u2019re about 5mm across, with a bright red stomach<\/strong> visible through their transparent body. They eat plankton<\/strong>, tiny molluscs<\/strong>, larvae<\/strong> and fish eggs<\/strong>.<\/p>\n

CAN THEY LIVE FOREVER?<\/strong><\/p>\n

Now\u00a0T. dohrnii<\/em>\u00a0jellyfish can be eaten by bigger creatures<\/strong> \u2013 so they are not truly immortal.<\/p>\n

But when this cool jellyfish suffers a physical attack, or starvation, or some kind of environmental stress, instead of dying, they change firstly into a tiny blob<\/strong>, and then back to the polyp stage<\/strong> within 3 days. They become another polyp colony sitting on a rock. The polyp is genetically identical<\/strong> to the original jellyfish \u2013 but is packaged differently.<\/p>\n

\"You'll<\/a><\/p>\n

Did that original jellyfish die? Not really. But did that original jellyfish continue to live in the same body? No. It\u2019s kind of like a butterfly that instead of dying changes back to a caterpillar \u2013 or an aged chicken turning back into an egg.<\/p>\n

So technically it\u2019s more like \u201cregeneration<\/strong>\u201d \u2013 but it\u2019s the closest that we have to immortality. And once scientists learn how T. dohrnii<\/em> does it, they could apply this knowledge to medical science<\/strong> for humans.<\/p>\n

\u00a9 Karl S. Kruszelnicki Pty Ltd 2016<\/p>\n

<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

There have always been myths about immortality, the ability to live forever. But is it possible? Well, marine biologists have found a creature that comes close \u2013 a tiny, transparent jellyfish. WHAT ARE THEY? While it has the unofficial name of ‘immortal jellyfish‘, its official name is Turritopsis dohrnii\u00a0(it used to be\u00a0Turritopsis nutricula). After an … Continue reading Science with Dr Karl: Immortal Jellyfish!<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":2069,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"categories":[28],"tags":[124,126,125,123],"christmas-category":[],"class_list":["post-926","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-nature","tag-immortal-jellyfish","tag-science-with-dr-karl","tag-sealife","tag-t-dohrnii","countries-australia","countries-ireland","countries-new-zealand","countries-south-africa","countries-united-kingdom"],"acf":[],"yoast_head":"\nScience with Dr Karl: Immortal Jellyfish! - National Geographic Kids<\/title>\n<meta name=\"description\" content=\"Ready for something awesome?! 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