Camouflage is a process through which animals change colors in accordance with the surrounding environment, becoming hardly distinguishable from it. The two most common processes animals use to change color are chemical or physical coloration. In chemical coloration, animals use microscopic natural pigments in their body named chromatophores, which absorb some colors of light and reflect others. In physical coloration, on the other hand, animals produce colors via microscopic physical structures that function like prisms, refractingand scattering light causing a certain combination of colors to reflect. Let me now introduce you to some of the most fascinating creatures using different color camouflage techniques.
Mimic Octopodes
Lurking in the Indonesian and Malaysian shallow open waters is the newely dicovered master of underwater color camouflage: the Mimic Octopus. Like chameleons, Mimic Octopodes use pigment-filled chromatophores for coloration; not only that, to dodge away hungry predators,
these creatures skillfuly contort to impersonate a large variety of sea creatures including sea snakes, lionfish, jellyfish and sole fish.
To mimic a lionfish, the Mimic Octopus adopts striped patterns on its skin and swims surrounded by its floating arms that resembles the fish's many venomous spines. Similarly, to mimic deadly sea snakes, it buries its body, leaving two arms out and moving them together.
"The intelligence implied by their ability to mimic different kinds of sea animals depending on the circumstances is astonishing" said Healy Hamilton, Director of Applied Biodiversity Informatics Center at the California Academy of Sciences. According to the kind of threat it faces, this octopus reacts by changing its color and shape to look as predators of its own predators.
Seahorses
known as the chameleons of the seas, seahorses are known for their skillful color camouflage abilities that set them among the most famous hiders and seekers in marine life.
Seahorses are beautiful small sea creatures that swim in an upright position with their tails down and their heads up. They exsit in tens of species distributed all over the world, usually inhabiting coral reefs and seagrass beds.
These small creatures change color in response to different factors including stress, social interactions, temperature, disease and diet. Being poor swimmers, seahorses also change color to blend with their surroundings, seeking protection from their predators and aiming to catch their preys.
Seahorses change color through contracting or expanding the pigment cells in their skin, showing a wide set of colors including shades of green, orange, red, black and white. Moreover, some species can grow extra skin filaments that make them similar in shape to fronds of seaweed, or long appendages that make them match the surrounding corals even better.
*Published in PSC Newsletter, 2nd School Semester 2012/2013 issue.
References
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