1. Cuttlefish: The Colorblind Masters
of Camouflage
Example of Cuttlefish
http://www.youtube.co
m/watch?v=Bm-
8i89Qwkc&list=PL78925
FA46CFDFD45
http://web.stagram.com/tag/cuttlefish/
http://www.nicerweb.com/sketches/video/NATGEO-DevilsOfTheDeep/
http://www.123rf.com/photo_5962644_cuttlefish-at-palong-divesite-phi-phi-thailand.html
http://www.newscientist.com/blog/shortsharpscience/2006/04/cuttlefish-
camouflage.html

2. Introduction to Cuttlefish
• 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.
www.survivalofthebeautiful.com
• 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.
http://www.greyops.net/2010/05/active-camouflage-camouflage-
week.html

3. 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
http://www.astro.virginia.edu/class/oco
nnell/astr130/human-eye.html
and cones
http://redalertpolitics.com/2012/12/08/text-messages-direct-to-your-contact- • Rods perceive the contrast (how
lens/the-human-eye/
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
http://psychology.wikia.com/wiki/Retinal
the optic nerve and tells us the contrast
or color of what we are seeing.

4. 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
http://www.jonbondy.com/cuttlefish3.htm they can perceive polarized light
Photoreceptor configurations in cuttlefish eye
• They can see polarized light because
there is an orthogonal structure of
photoreceptors in the cuttlefish’s eye.
• Cuttlefish may use the polarization
Photoreceptor configurations in human eye 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.
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

5. How their camouflage works
Chromatophores
• Cuttlefish have 3 layers of cells in their • Chromatophores are pigment-containing
skin that contribute to their unique and light-reflecting organelles in cells and
camouflage are controlled by muscles that translocate
• Chromatophores pigment and reorient reflective plates.
• Iridophores
Iridophores
• Leucophores • 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.

6. 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.