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The Colourful World of Cephalopods - Cephalopod body patterning IV<< Cephalopod Articles | byWhy cephalopods use body patterning It would certainly give most of us an epic sized head-ache to balance all these patterning control elements just to perform basic tasks like getting food and interacting with those around us. Why do cephalopods have these amazing body patterns?  One reason is camouflage, which can be used to several advantages. Blending into the background, or imitating other animals lets them approach unsuspecting prey more easily. Some scientists hypothesize that less cryptic hunting patterns might be used to mesmerize prey. Also, as most cephalopods have little external protection for their soft bodies, it is in their best interest not to be easily found. They are a tempting soft snack for hungry fish and eels that can see them!
When found, cephalopods sometimes change colour rapidly, perhaps as a message to the predator that they have been seen, and might find it easier to hunt an unsuspecting prey. In this way, cephalopods communicate with their predators. It is pretty obvious that the Caribbean reef squid, Sepioteuthis sepioidea, uses colour to communicate with others of the same species. When competing for females, males will show an intense zebra display to each other. Often, they determine the dominant male by this display and without physically fighting with each other. This is highly ritualized communication using colour and shape. One researcher has even hypothesized that Caribbean reef squid display language on their skin, with various parts of the their body patterns representing nouns (Signalers) and adjectives (Modifiers). Although this is a fantastic theory to most, it testifies to the wonder that these dynamic and seemingly intelligent animals invoke in us. They certainly can be used as an out-group for studies on vertebrate communication. And who knows, maybe one day we will have the technology to be like cephalopods and reflexively turn our thoughts into print simply by using neural control. I wonder if that will happen before I type up my thesis.... So next time you see a slug, exclaim excitedly, "Look, a slug!!!" Who knows what wondrous secrets these animals, like their cephalopod cousins, are waiting to share with us. To go back to page 3, click here. More exciting work on cephalopod senses and communicationFor those of you who just can't get enough of these amazing creatures and how theyinteract with the world, head down to your local library and check out the following topics:Lateral line analogues Fish have special lines on their sides that allow them to detect the movement of other animals in the water. These are called lateral lines. It seems that cephalopods have a similar ability. Their lines runalong their arms and head. Hanlon and Messenger (1996) offer an overview of these organs intheir book, with Dr. Budelmann and his colleagues being involved with much of the primary research. The use of polarized light in dermal patterning Many animals and plants can use light that humans can't. For example, bees can see in ultraviolet, an ability that some flowers use to make themselves extra attractive to prospective pollination. It is now being discovered that cephalopods might also have an ability to see things that humans can't. It has been fairly well established that cephalopods can't see in colour, but they might get extra information by seeing the planeof polarization of light. Nadav Shashar is doing a lot of the primary research on the topic. References and CreditsCreditsAlison would like to thank Roland Anderson for his dialogue on the differences between photophores and other types of bioluminescence in cephalopods. She would also like to thank Ian Gleadall for his helpful suggestions after reviewing her page online and providing more information about current (and past) bioluminescence studies. Thanks to the photographers who were:Images in page 1: Adult cuttlefish, Sepia officinalis - James B. Wood Images in page 2: Australian giant cuttlefish, Sepia apama - Geoff Costello, Caribbean reef squid, Sepiateuthis sepioidea - Roger Hanlon, Euprymna scolopes - Roland Anderson Images in page 3: Adult cuttlefish, Sepia officinalis - James B. Wood Images in page 4: Caribbean reef squid, Sepiateuthis sepioidea - John Forsythe ReferencesBrusca R.C. and Brusca G.J. (1990). Phylum Mollusca. IN Invertebrates. Sinauer Associates, Sunderland, pp. 695-769.Cooper K.M. et al. (1990). Physiological color change in squid iridophores. II. Ultrastructual mechanisms in Lolliguncula brevis. Cell Tissue Res., 259: 15-24. Hanlon R.T. et al. (1990). Physiological color change in squid iridophores. I. Behavior morphology and pharmacology in Lolliguncula brevis. Cell Tissue Res., 259: 3-14. Hanlon R.T. and Messenger J.B. (1996). Cephalopod Behavior. Cambridge University Press, Cambridge. Mather J.A. (1995). Cognition in Cephalopods. Advances in the study of behavior, 24: 317-353. Packard, A. (1995). Organization of cephalopod chromatophore systems: a neuromuscular image-generator. IN Cephalopod Neurobiology. Abbott, N.J., Williamson, R. and Maddock, L. (Eds.). Oxford, Oxford University Press. pp. 331-368.
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