While pondering what animal to work on for this assignment, my friend aka Chatter came and approached me on MSN to go for a graduation dive trip. Already at my wits end for this assignment, I still have to face all the pestering and bombardment of her underwater pictures and videos. Well, I decided to entertain her by showing interest in her youtube videos and that “tiny” respect for girls pays off. One of her captures caught my attention and made me realize something. Out of so many diving trips, I have missed something that is not as significant as whale sharks or stingrays but something that can fascinate most of the leisure divers. Judging by the title of this article, I can probably forgive myself for not making my dives more worthwhile.
The thought of camouflaging leads many to think of chameleon which is the most common animal to display fineness art of disguising. However, another expert in this field is the cuttlefish, collectively known as cephalopods. Cuttlefish are soft-bodied marine cephalopods, with a large head ringed by tentacles and an internal cuttlebone. Cuttlefish displays various skills of natural camouflage, sepia ink squirting, jet propulsion and neutral buoyancy. This article shall focus on their amazing skill of camouflaging which surprisingly is used for many purposes.
Camouflaging Colours
Cuttlefish is a master of disguise by utilizing its internal mechanism which is its skin covered with special cells (chromatophores, iridophores and leucophores) that can reflect light in many colours. Refer to the video below for youtube video showing changing colours of cuttlefish.
*my friends’ dive trip video capture of a cuttlefish changing colours rapidly while adopting defensive posture
According to Robert Hanlon of the Woods Hole Marine Biological Laboratory, there are three board categories of camouflage patterns: uniform colour, mottled colour, and disruptive patterns (like stripes and spots). Dr Hanlon even went to the extent to test whether the cuttlefish is able to blend with a black and white checkboard and it turns out that it responds by forming astonishingly sharp-edged blocks of white. What is more astonishing is the fact that cuttlefish is colour-blind although they are able to perceive the polarization of light.
Additional Camouflaging Enhancement Skills
Besides the instinctive skill of changing colours, cuttlefish is able to blend with the surroundings. Researchers have said that cuttlefish is far more superior to chameleon in camouflaging skills as they are able to display spatial learning. They are able to blend into surroundings by forming the same texture as the surrounding environments. Refer to video below for flamboyant cuttlefish camouflaging with change of texture and colour.
Furthermore, they do not just mimic the colours of the surroundings, they are able to disguise by making their arms flat and crinkled and wave them like seaweed. Cuttlefish is well-known for being one of the smartest creatures in the marine world and this kind of behavior may be due to imprinting.
Functional Aspects of Camouflaging
Cuttlefish uses camouflaging for different purposes and the most common purpose is defence and predatory instinct. Refer to video below to look at how cuttlefish camouflages itself under the sand to wait for its prey.
Trickery Mating and Courtship
Cuttlefish also uses camouflaging as a courtship strategy. It’s changing colour ability is able to display sexual deception where they disguise as females to elude from their adversaries before discretely mate with the genuine article.
Conclusion
There is lots of marine life out in a lot of dive sites that is worthwhile to observe. This module and my friend has made me realize that diving is not only about understanding the beauty of the underwater, but it is also about understanding animal before we can discover their hideouts as well as to conserve them.
References
The Biology Refugia. (2008). Secrets of Cuttlefish Camouflage. Retrieved March 21, 2008, from
http://staff.science.nus.edu.sg/~sivasothi/biorefugia/2008/02/secrets-of-cuttlefish-camouflage.html
New York Times- Science. (2008). Revealed: Secrets of the Camouflage Masters. Retrieved March 21, 2008, from
http://www.nytimes.com/2008/02/19/science/19camo.html?_r=2&pagewanted=1&ref=science&oref=slogin&oref=slogin
Tonmo. (2003). Cuttlefish Basics. Retrieved March 21, 2008, from
http://www.tonmo.com/articles/basiccuttlefish.php
Wikipedia. (2008). Cutterfish. Retrieved March 21, 2008, from
http://en.wikipedia.org/wiki/Cuttlefish
Nova. (2007) Mating Trickery. Retrieved March 21, 2008, from
http://www.pbs.org/wgbh/nova/camo/mating.html