The soft-bodied coleids, including cuttlefish, octopi and squids, developed during the Triassac period (Packard, 1972 Messenger, 2001). This was due to the evolution of air-filled chambers connected by the siphuncle, which allowed them to control buoyancy. The first cephalopods appeared 500 mya with hard external shells and the ability to leave the ocean bottom- unlike the mollusks they evolved from. To contextualize the phylogenetic development of color-changing behavior in cuttlefish, we examine both the phylogeny of the species and the cuttlefish eye.Ĭuttlefish are of the phylum Mollusca class cephalopoda, order sepioloida, and family sepiidae (Battler and Alcock, 2012). Furthermore, a model in which the visual feature system is implemented in a hierarchical fashion (i.e., when needed, to fine tune a basic response to the overall background), in order for the animal to create the myriad camouflage responses used on the sea floor.Cuttlefish Camouflage Phylogeny Cuttlefish Camouflageīiology 342 Fall 2014 Emily Merfeld & Nicolette Tapia Whilst the study findings are preliminary, they are in line with a model in which European cuttlefish do employ a cognitive system that processes specific visual features of the environment, and which is used in combination with a system which responds to the visual background overall. Instead, the findings were more in line with a system whereby the whole range of the animals’ body pattern components could be activated, but selectively and in limited numbers, in response to the patterned feature they had been visually exposed to in the water tank. The results of the PCA found that a few key characteristics did not explain most of the variability in the experimental data, but which would have been expected if the cuttlefish were employing a cognitive system which was expressing only three body patterns. The analysis included a statistical technique called ‘principal component analysis’ (PCA) which searches for clusters of responses in the observed data and attempts to largely explain it with a reduced set of key characteristics of the data. The animals’ camouflage responses to these visual cues were photographed with a camera, and then analysed to see which of the 30 body pattern components appeared activated across the sample of test subjects. In the study, 15 European cuttlefish were independently acclimated to a small water tank in which they were randomly exposed to either a uniform, grey background, or one of seven backgrounds with detailed, patterned features (e.g., small black squares, small white squares, white stripes). Like their cephalopod relatives the octopus and the squid, cuttlefish are masters at blending in with their environments, which is largely attributable to the way their brains are able to control how pigments in special cells called chromatophores on their skin are displayed across their bodies. ![]() The study explored whether the cuttlefish uses a cognitive process that is triggered by specific, visual features in its environment and which warrants the number of body pattern components it possesses. However, that does not explain why the animal possesses about 30 different body pattern components it could use to achieve this. This is in contrast to previous research suggesting that the cognitive (brain) processes involved are much simpler, in that the cuttlefish adopts one of only three major types of body patterns to visually merge with its background. Cuttlefish camouflage may more complex previously thoughtĪ new study by City, University of London and others suggests that the European cuttlefish (sepia officinalis) may combine two distinct neural systems that process specific visual features from its local environment, and visual cues relating to its overall background environment, in order to create the body patterns it uses to camouflage itself on the sea floor.International agents and representatives.School of Health & Psychological Sciences.Job prospects and graduate destinations.Placements, internships and employment opportunities.Lesbian, gay, bisexual, transgender and queer plus.
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