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robertogreco : squid   18

You're Not Hallucinating. That's Just Squid Skin. | Deep Look - YouTube
"Octopuses and cuttlefish are masters of underwater camouflage, blending in seamlessly against a rock or coral. But squid have to hide in the open ocean, mimicking the subtle interplay of light, water, and waves. How do they do it? (And it is NOT OCTOPI)"



"--- How do squid change color?

For an animal with such a humble name, market squid have a spectacularly hypnotic appearance. Streaks and waves of color flicker and radiate across their skin. Other creatures may posses the ability to change color, but squid and their relatives are without equal when it comes to controlling their appearance and new research may illuminate how they do it.

To control the color of their skin, cephalopods use tiny organs in their skin called chromatophores. Each tiny chromatophore is basically a sac filled with pigment. Minute muscles tug on the sac, spreading it wide and exposing the colored pigment to any light hitting the skin. When the muscles relax, the colored areas shrink back into tiny spots.

--- Why do squid change color?

Octopuses, cuttlefish and squid belong to a class of animals referred to as cephalopods. These animals, widely regarded as the most intelligent of the invertebrates, use their color change abilities for both camouflage and communication. Their ability to hide is critical to their survival since, with the exception of the nautiluses, these squishy and often delicious animals live without the protection of protective external shells.

But squid often live in the open ocean. How do you blend in when there's nothing -- except water -- to blend into? They do it by changing the way light bounces off their their skin -- actually adjust how iridescent their skin is using light reflecting cells called iridophores. They can mimic the way sunlight filters down from the surface. Hide in plain sight.

Iridophores make structural color, which means they reflect certain wavelengths of light because of their shape. Most familiar instances of structural color in nature (peacock feathers, mother of pearl) are constant–they may shimmer when you change your viewing angle, but they don't shift from pink to blue."
chromatophores  2015  squid  octopus  cuttlefish  camouflage  classideas  science  multispecies  nature 
august 2018 by robertogreco
Something Fishy in the Atlantic Night : Feature Articles
"About 300 to 500 kilometers (200 to 300 miles) offshore, a city of light appeared in the middle of the South Atlantic Ocean. There are no human settlements there, nor fires or gas wells. But there are an awful lot of fishing boats.

Adorned with lights for night fishing, the boats cluster offshore along invisible lines: the underwater edge of the continental shelf, the nutrient-rich Malvinas Current, and the boundaries of the exclusive economic zones of Argentina and the Falkland Islands.

The night fishermen are hunting for Illex argentinus, a species of short-finned squid that forms the second largest squid fishery on the planet. The squid are found tens to hundreds of kilometers offshore from roughly Rio de Janeiro to Tierra del Fuego (22 to 54 degrees South latitude). They live 80 to 600 meters (250 to 2,000 feet) below the surface, feeding on shrimp, crabs, and fish. In turn, Illex are consumed by larger finfish, whales, seals, sea birds, penguins...and humans.

The fishery is fueled by abundant nutrients and plankton carried on the Malvinas Current. Spun off of the Circumpolar Current of the Southern Ocean, the Malvinas flows north and east along the South American coast. The waters are enriched by iron and other nutrients from Antarctica and Patagonia, and they are made even richer by the interaction of ocean currents along the shelfbreak front, where the continental shelf slopes down to the deep ocean abyssal plain.



Scientists first noted such night-lighting of the seas in the late 1970s and early 1980s, while compiling the first maps of the Earth at night. The images from the Operational Linescan System on the polar-orbiting satellites of the Defense Meteorological Satellite Program (DMSP) clearly showed fishing boats working the waters off of Japan, China, and Korea.



Fisheries researchers and managers suggest that as much as 300,000 tons of Illex squid are harvested from the South Atlantic each year by unlicensed, unregulated fishing vessels. Managing the fishery and monitoring the presence of foreign fishing fleets is very difficult for navies and fisheries managers; the satellite views provide at least some sense of the activity in the area.

“These lights help reveal the full range, patterns, and night-to-night variability of these fishing activities in striking detail,” said Steve Miller, a Colorado State University scientist who works with VIIRS nighttime imagery. “It’s just another example of how much information exists in these measurements and how unique they are for coupling human activity with the natural environment in a way that conventional visible imagery cannot do.”"

[via: http://notes.husk.org/post/65057439543/squid-fishing ]
malvinas  falklands  fishing  argentina  atlantic  night  light  squid  cephalopods  chlorophyll  plankton 
october 2013 by robertogreco
Backyard Brains » Insane in the Chromatophores
"During experiments on the giant axons of the Longfin Inshore Squid (loligo pealei) at the Marine Biological Laboratory in Woods Hole, MA; we were fascinated by the fast color-changing nature of the squid’s skin. Squids (like many other cephalopods) can quickly control pigmented cells called chromatophores to reflect light. The Longfin Inshore has 3 different chromatophore colors: Brown, Red, and Yellow. Each chromatophore has tiny muscles along the circumference of the cell that can contract to reveal the pigment underneath.

We tested our cockroach leg stimulus protocol on the squid’s chromatophores. We used a suction electrode to attach to the squid’s fin nerve, then connected the electrode to an iPod nano as our stimulator. The results were both interesting and beautiful. The video below is a view through an 8x microscope zoomed in on the dorsal side of the fin."

[via: http://www.cesarharada.com/squid-hop/ via http://www.flickr.com/photos/worldworldworld/7887219272/ ]
science  greggage  animals  cockroaches  2012  color  membranes  robotics  muscles  music  biology  squid  chromatophores 
august 2012 by robertogreco
collision detection: The Humboldt squid beak: Diamond-sharp mystery of the briny deep
"There are many weird things about the giant Humboldt squid, but here’s one of the strangest: Its beak. The squid’s beak is one of the hardest organic substances in existence — such that the sharp point can slice through a fish or whale like a Ginsu knife. Yet the beak is attached to squid flesh that itself is the texture of jello. How precisely does a gelatinous animal safely wield such a razor-sharp weapon? Why doesn’t it just sort of, y’know, rip off? It’s as if you tried to carve a roast with a knife that doesn’t have a handle: It would cut into your fingers as much as the roast."
squid  edg  materials  biomimicry  animals  nature  biomimetics 
september 2008 by robertogreco
Climate Change: Giant Squids Invade The Dead Zones Of California
"The massive squid predators feed off the "free suffocated food at the edge of that anoxic zone," writes senior ocean analyst Kate Wing. "Like a jubilee for cephalopods.""
squid  animals  oceans  food  deadzone  anoxiczone 
february 2008 by robertogreco
Dark Roasted Blend: The Machine-Animals of Nantes
"French city of Nantes recently became host to extremely strange and fascinating sculptural display: "Les Machines de l'Ile Nantes", designed by François Delarozière and Pierre Orefice."
animals  robotics  robots  squid  sculptures  exhibitions  machines  sculpture  puppets  steampunk 
january 2008 by robertogreco
California's attack of the jumbo squid - earth - 23 July 2007 - New Scientist Environment
"Ferocious, pack-feeding jumbo squid have invaded waters off California's central coast and are devouring local fish populations. Researchers say global warming and overfishing are likely to blame."
squid  animals  globalwarming  oceans  marine 
july 2007 by robertogreco
collision detection: Bioluminescent killer squid caught on video!
"a bunch of Japanese scientists finally managed to capture the dread Dana Octopus Squid on camera"
science  animals  squid  video  nature  biology 
february 2007 by robertogreco
Pink Tentacle
"Toyama Bay is the habitat of the world-famous glowing firefly squid, which surface in large numbers every spring in a phenomenon that has been designated a special natural monument. Peak firefly squid season means big catches for fishermen and brisk busi
animals  biology  science  squid  japan  nature  photography  light 
april 2006 by robertogreco
BBC NEWS | Science/Nature | Giant squid grabs London audience
"One of the biggest and most complete giant squids ever found is on display at London's Natural History Museum."
squid  animals  biology  science 
march 2006 by robertogreco

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