字幕表 動画を再生する 英語字幕をプリント My time has finally come. Today, I get to talk about Cephalopods Hey guys, Julia here for Dnews Octopi and their fellow cephalopods scare the living daylights out of my sister. Something about a traumatic trip on the 20,000 leagues under the Sea Ride…. So sister, you should probably turn off this episode, because it turns out, there's a lot to be afraid of. Okay in my opinion there's a lot to love about these molluscs. Like a recent discovery that some species of octopuses can see through their skin. Seriously. Octopuses make a chemical in their eyes called opsins, which react to light, and send a chemical signal to the brain. In two studies published in the journal of Experimental Biology, researchers found that these molecules can also be found in their skin. In octopuses, these molecules are in nerve endings on the cell. These little hair like extensions detected light and send a chemical signal to specialized color changing cells on their skin called chromatophores. In other cephalopods like squid and cuttlefish, opsins are actually found in the chromatophores themselves. Scientists think this might be how cephalopods have such an uncanny ability to blend into their surroundings. Oh yeah these guys are masters of camouflage. I mean, some cephalopods have have up to 96,000 chromatophores per square inch of skin. Each of these chromatophores contain a sac of pigment surrounded by muscle and by stretching or squeezing this sac, they can change the appearance of their colors. Some species of cephalopods have other crazy color cells, like iridophores which make iridescent colors, or leucophores which mirror back the environment. But besides changing colors, some cephalopods can change texture. yeah crazy, In a study published in the Journal of Morphology researchers found that cephalopods have small muscular structures on their skin that either poke up vertically in a spike or bump or spread out nice and smooth. So they can morph into crazy patterns and changing textures in their environment, like mimicking corals, rocks or sand. Or mimicking other sea creatures like T. mimicus, an Indo-Pacific species of octopus. Not only are they great pretenders but they are crazy crazy smart. Like they've been known to pull pranks and play in captivity. According to Canadian biologist Jennifer Mather, they blow water at stuff in their tanks or take apart stuff like robots, just for the fun of it. And play is something thought to only be found in intelligent creatures, like birds and apes. There's so many stories of them sneaking out of their tanks at night and stealing a fish or two from a nearby tank then plopping back in their tank and acting like nothing happened. Mather even noticed that octopuses have personalities, different creatures are more shy or active than others. These come from their big brains, well relatively. They're brains aren't as big as ours per say, but bigger than many other molluscs. Most molluscs have “brains” that are actually clusters of nerve cells spread throughout the body. But cephalopods have a more centralized group of these ganglia, or nerve cells. This centralizes command in the creature and provides more room for developing things like memory. They also have little mini brains or groups of nerve cells in their arms! I haven't even mentioned that cuttlefish are adorable and cuddly… an octopus has a beak or some species have an arm, called a A hectocotylus, that acts a lot like penis by storing and transferring sperm to the female. Which just gets weird. Speaking of the weird and wonderful, Laci explains all about real life sea monsters in this great video here …