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Cuttlefish: The Colorblind Masters of Camouflage http://www.newscientist.com/blog/shortsharpscience/2006/04/ cuttlefish-camouflage.html http://www.nicerweb.com/sketches/video/NATGEO-DevilsOfTheD eep / http://web.stagram.com/tag/cuttlefish / http:// www.123rf.com/photo_5962644_cuttlefish-at-palong-divesite-phi- phi-thailand.html http:// www.youtube.com/w atch?v=Bm-8i89Qwk c&list=PL78925FA4 6CFDFD45 Example of Cuttlefish

Cuttlefish masters of camouflage

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Page 2: Cuttlefish masters of camouflage

Introduction to Cuttlefish

www.survivalofthebeautiful.com

http://www.greyops.net/2010/05/active-camouflage-camouflage-week.html

• Cuttlefish are marine animals that are related to octopi. They have large W-shaped pupils, eight arms, two tentacles, and have the largest brain-to-body size ratios of all invertebrates.

• Cuttlefish have the ability to change the color of their skin to camouflage into the surroundings giving it the nickname “chameleons of the sea”.• They can change between colors in a matter of

seconds.• They can camouflage themselves even in the

dark.• And they also have circular muscles which

they can use to change the structure of their skin to enhance camouflage.

Page 3: Cuttlefish masters of camouflage

How do we see?• Human eyes work a lot like the eyes of

cuttlefish but we can see colors.

• Ours eyes use photoreceptors called rods and cones• Rods perceive the contrast (how

light or dark)• Cones perceive the color

• When the light approaches these receptors, retinal molecules change forms from 11-cis-retinal (A) to all-trans-retinal (B). As you can see this makes the molecule change shape.

• This shape change ultimately leads to the generation of a nerve impulse

• And that impulse then goes to through the optic nerve and tells us the contrast or color of what we are seeing.

http://psychology.wikia.com/wiki/Retinal

http://redalertpolitics.com/2012/12/08/text-messages-direct-to-your-contact-lens/the-human-eye/

http://www.astro.virginia.edu/class/oconnell/astr130/human-eye.html

Page 4: Cuttlefish masters of camouflage

How do they see?• Cuttlefish eyes only contains rods, so it

is unable to perceive color.

• But cuttlefish have one of the most highly developed eyes of any animal and they can perceive polarized light

• They can see polarized light because there is an orthogonal structure of photoreceptors in the cuttlefish’s eye.• Cuttlefish may use the polarization

of light much like we use color• Because they can see polarized light

cuttlefish can respond to subtle changes in the angle of the light and it adds resolution to their vision.

Photoreceptor configurations in human eye

Photoreceptor configurations in cuttlefish eye

Photoreceptors in the human eye are not arranged in any specific order making it very difficult for us to see how light is polarized but the Cuttlefish’s receptors have a definite arrangement that allows them to see the changes

http://www.jonbondy.com/cuttlefish3.htm

Page 5: Cuttlefish masters of camouflage

How their camouflage worksChromatophores

• Chromatophores are pigment-containing and light-reflecting organelles in cells and are controlled by muscles that translocate pigment and reorient reflective plates.

Iridophores• Iridophores are pigment-containing cells

that reflect light using plates of crystalline chemochromes made from guanine, which is part of DNA and RNA bases.

• When illuminated Iridophores generate metallic colors because of the diffraction of light within the stacked plates.

• Iridophores create an optical effect known as Rayleigh scattering, that producing bright blue or green colors.

Leucophores• Leucophores are flat cells that reflect all

colors of light at all angles.

• Cuttlefish have 3 layers of cells in their skin that contribute to their unique camouflage• Chromatophores• Iridophores• Leucophores

Page 6: Cuttlefish masters of camouflage

References• http://www.underwatertimes.com/news.php?article_id=23954817601• http://www.nicerweb.com/sketches/video/NATGEO-DevilsOfTheDeep/• http://www.jonbondy.com/cuttlefish3.htm• http://tolweb.org/notes/?note_id=2646• http://news.softpedia.com/news/Invisibility-039-s-Secret-May-Lay-in-the-Skin-of-the-Octopus-

42790.shtml• http://blogs.scientificamerican.com/octopus-chronicles/2012/02/20/polarized-display-sheds-light-on-

octopus-and-cuttlefish-vision-and-camouflage/• http://io9.com/5886954/cuttlefish-are-the-first-known-species-to-see-the-world-in-polarized-light• http://jeb.biologists.org/content/199/9/2077• http://news.nationalgeographic.com/news/2008/08/080608-cuttlefish-camouflage-missions_2.html• http://www.seafriends.org.nz/indepth/octopus.htm• http://psychology.wikia.com/wiki/Retinal• http://en.wikipedia.org/wiki/Cuttlefish• Skold, H. N.; Aspengren, S.; Wallin, M. Rapid color change in fish and amphibians - function,

regulation, and emerging applications. Pigment Cell Melanoma Res. 2013, 26, 29-38.• Maethger, L. M.; Bell, G. R. R.; Kuzirian, A. M.; Allen, J. J.; Hanlon, R. T. How does the blue-ringed

octopus (Hapalochlaena lunulata) flash its blue rings? J. Exp. Biol. 2012, 215, 3752-3757• Kreit, E.; Maethger, L. M.; Hanlon, R. T.; Dennis, P. B.; Naik, R. R.; Forsythe, E.; Heikenfeld, J.

Biological versus electronic adaptive coloration: how can one inform the other? J. R. Soc. Interface 2013, 10, 20120601.