{"id":2208591,"date":"2026-10-17T18:00:36","date_gmt":"2026-10-17T16:00:36","guid":{"rendered":"https:\/\/focusingonwildlife.com\/news\/?p=2208591"},"modified":"2026-10-17T14:22:50","modified_gmt":"2026-10-17T12:22:50","slug":"world-octopus-day-new-discoveries-about-the-worlds-smartest-invertebrates","status":"publish","type":"post","link":"https:\/\/focusingonwildlife.com\/news\/world-octopus-day-new-discoveries-about-the-worlds-smartest-invertebrates\/","title":{"rendered":"World Octopus Day: new discoveries about the world\u2019s smartest invertebrates"},"content":{"rendered":"

Happy World Octopus Day! \u00a0Every Oct 8, the world celebrates one of the more unusual creatures of the sea. Octopuses are well-known for their eight legs and ability to squirt ink when frightened. They\u2019ve also been known to use tools, a sign of intelligence, and can shape-shift to mimic the colors and texture of their surroundings, an effective way to disappear from both predators and prey.<\/p>\n

Modern colossal squid are believed to be the largest invertebrates in the sea, but Mongabay\u2019s Shanna Hanbury recently reported on an even larger ancient octopus species whose fossils were described by Japanese researchers\u00a0in April 2026.<\/p>\n

The Japanese team found a fossilized jawbone from the now-extinct Nanaimoteuthis haggarti. <\/em>Based on its jaw size, researchers suggest the octopus may have reached 6.6 to 18.6 meters (22 to 61 feet) in length. On the higher end, that\u2019s around two-thirds the size of an adult blue whale, the largest animal to ever exist.<\/p>\n

\u201cIt suggests that it may have been among the largest invertebrates ever known,\u201d study co-author Yasuhiro Iba, a paleontologist at Hokkaido University in Japan, told Mongabay by email.<\/p>\n

They were likely gigantic predators that roamed the late Cretaceous seas between 100 million to 72 million years ago.<\/p>\n

From long dead octopus to newly born, Hanbury also reported on baby Argentine octopuses and a rare photo of them.<\/p>\n

\"Patagonian
Patagonian octopus eggs in Puerto Lobos Protected Natural Area in Argentina. Image courtesy of Martin Brogger.<\/figcaption><\/figure>\n

These eggs belong to a small\u00a0Patagonian octopus\u00a0(Octopus tehuelchus<\/em>). It\u2019s one of the more common octopus species in the region, but researchers still haven\u2019t been able to determine its global conservation status, although reported catches in Patagonia have\u00a0declined\u00a0over the past 50 years.<\/p>\n

The black dots inside each egg are the developing eyes of the embryos, indicating that they\u2019re progressing toward hatching.\u00a0The female octopus of this species often lays her eggs in the shell of an\u00a0oyster, then guards them fiercely. She even\u00a0stops eating\u00a0during this period.<\/p>\n

New octopus species are described often, including a blue octopus about the size of a golf ball recently discovered in the Galapagos.<\/p>\n

On a deep-sea expedition in 2015, scientists used a remotely operated vehicle to find a golf-ball sized, short-armed blue octopus. In a\u00a0recent study, they confirmed that it\u2019s new to science, reported Mongabay\u2019s David Brown.<\/p>\n

However, questions remain about how the new species, Microeledone galapagensis<\/em>, makes use of its stubby arms.<\/p>\n

\u201cIf you gather prey by moving your arms through the sediment (as we think they do), wouldn\u2019t it be better to have longer arms with more suckers than short little arms?\u201d queried lead author Janet Voight.<\/p>\n

<\/p>\n

This article<\/a> by David Brown was first published by Mongabay on 8 October 2026. Lead Image: Big blue octopus (Octopus cyanea) with a diver in background. Image courtesy of David Fleetham\/WWF via naturepl.com.<\/em><\/p>\n