Spectacular Cephalopods

6 responses to “Spectacular Cephalopods”

1. 

   BWJones

   Jan 27, 2010 at 6:24 am

   Used to have an octopus as a pet. Named her Cephus, short for cephalopod. She was one amazing animal, no doubt.

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2. 

   BWJones

   Jan 27, 2010 at 6:27 am

   As to their eyes, there is more to it. A cephalopods retina is backwards from ours, configured like you’d imagine it since they do not apparently have the metabolic demands that our retinas do. Still, they are quite sophisticated retinas. By the way, mammals do not have nearly the sophisticated retinas that even the lowly goldfish or turtle has. We see in 3 colors, turtles may see in 7-9 colors.

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3. 

   Todd Huffman

   Jan 27, 2010 at 2:25 pm

   Cuttlefish: GO!

   xkcd.com/520/

   

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4. 

   jurvetson

   Jan 27, 2010 at 6:21 pm

   200 DPI body screens! …image all that wasted ad space….

   xkcd reminds me of a classic Far Side
   

   BWJones: mind bending. I was amazed at the wide 4D color space of birds, and 9D has me spinning in a hypertorus…

   And how about the tadpoles rewiring their visual pathways with a single gene trigger when they become frogs and move from prey to predator (watchful eyes on the side -> overlapping binocular vision looking forward).

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5. 

   BWJones

   Jan 28, 2010 at 6:26 am

   Even cooler than the single gene trigger in tadpoles… Those more "primitive" organisms such as frogs, goldfish and salamanders can *fix* their more complex retinas when injured or damaged. They have a population of stem cells that hangs out in the glial cell population and dedifferentiates upon injury to start forming all the cell classes again, essentially remaking their retinas.

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6. 

   jurvetson

   Mar 31, 2012 at 4:52 pm

   Magic Eyes!

   

   And here are some excerpts from that love story with the octopus:

   “I have always loved octopuses. No sci-fi alien is so startlingly strange. Here is someone who, even if she grows to one hundred pounds and stretches more than eight feet long, could still squeeze her boneless body through an opening the size of an orange; an animal whose eight arms are covered with thousands of suckers that taste as well as feel; a mollusk with a beak like a parrot and venom like a snake and a tongue covered with teeth; a creature who can shape-shift, change color, and squirt ink.

   Athena’s suckers felt like an alien’s kiss—at once a probe and a caress. Although an octopus can taste with all of its skin, in the suckers both taste and touch are exquisitely developed.

   Three-fifths of an octopus’s neurons are not in the brain; they’re in its arms. It is as if each arm has a mind of its own… For example, researchers who cut off an octopus’s arm (which the octopus can regrow) discovered that not only does the arm crawl away on its own, but if the arm meets a food item, it seizes it—and tries to pass it to where the mouth would be if the arm were still connected to its body.

   For its color palette, the octopus uses three layers of three different types of cells near the skin’s surface. The deepest layer passively reflects background light. The topmost may contain the colors yellow, red, brown, and black. The middle layer shows an array of glittering blues, greens, and golds. But how does an octopus decide what animal to mimic, what colors to turn? Scientists have no idea, especially given that octopuses are likely colorblind.

   But new evidence suggests a breathtaking possibility. Woods Hole Marine Biological Laboratory and University of Washington researchers found that the skin of the cuttlefish Sepia officials, a color-changing cousin of octopuses, contains gene sequences usually expressed only in the light-sensing retina of the eye. In other words, cephalopods—octopuses, cuttlefish, and squid—may be able to see with their skin.”

   And if that was not strange enough, the detachable arms that think for themselves take on a whole new meaning for the males…

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