Cephalopod Color and Skin discoveries

DWhatley

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SQUID COMMUNICATE WITH A SECRET, SKIN-POWERED ALPHABET
Wired
AUTHOR: ANNA VLASITS.ANNA VLASITS SCIENCE DATE OF PUBLICATION: 02.07.2017
Squid and their cephalopod brethren have been the inspiration for many a science fiction creature. Their slippery appendages, huge proportions, and inking abilities can be downright shudder-inducing. (See: Arrival.) But you should probably be more concerned by the cephalopod’s huge brain—which not only helps it solve tricky puzzles, but also lets it converse in its own sign language.

Right now, you’re probably imagining twisted tentacles spelling out creepy cephalopod communiqués. But it’s not that: Certain kinds of squid send messages by manipulating the color of their skin. “Their body patterning is fantastic, fabulous,” says Chuan-Chin Chiao, a neuroscientist at National Tsing Hua University in Taiwan. They can display bands, or stripes, or turn completely dark or light. And Chiao is trying to crack their code.

Chiao got his inspiration from physiologist B. B. Boycott, who in the 1960s showed that the cuttlefish brain was the control center for changing skin color. Boycott copied his technique from neurosurgeon Wilder Penfield, who treated epilepsy patients by burning out the misbehaving bits of their brains. While their grey matter was exposed for surgery, Penfield also applied a gentle current through the electrodes in his patients’ brains. You know, just to see what would happen.

A zap in one spot above the ears caused a tingle in the left hand. In another spot, tingles in the leg. And so Penfield discovered that the sensory cortex is a homunculus, with specific brain areas mapping onto different parts of your body. Over time, scientists tried the electrical stimulation technique on all kinds of animals—including Boycott’s cuttlefish.
 

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@Stavros Can I get you to add your authorship name and TONMO name to a new thread in the OctopusDen > Member's Publications forum (Members' Publications) I have you included in my Google Scholar search and found a new article but can't add it to the list until you initialize an entry.

SpotMetrics: an open source image-analysis software plugin for automatic chromatophore detection and measurement
Stavros P. Hadjisolomou, George El-Haddad 2017 (PDF available from Frontiers in Physiology)

Coleoid cephalopods (squid, octopus, and sepia) are renowned for their elaborate body patterning capabilities, which are employed for camouflage or communication. The specific chromatic appearance of a cephalopod, at any given moment, is a direct result of the combined action of their intradermal pigmented chromatophore organs and reflecting cells. Therefore, a lot can be learned about the cephalopod coloration system by video recording and analyzing the activation of individual chromatophores in time. The fact that adult cephalopods have small chromatophores, up to several hundred thousand in number, makes measurement and analysis over several seconds a difficult task. However, current advancements in videography enable high-resolution and high framerate recording, which can be used to record chromatophore activity in more detail and accuracy in both space and time domains. In turn, the additional pixel information and extra frames per video from such recordings result in large video files of several gigabytes, even when the recording spans only few minutes. We created a software plugin, “SpotMetrics,” that can automatically analyze high resolution, high framerate video of chromatophore organ activation in time. This image analysis software can track hundreds of individual chromatophores over several hundred frames to provide measurements of size and color. This software may also be used to measure differences in chromatophore activation during different behaviors which will contribute to our understanding of the cephalopod sensorimotor integration system. In addition, this software can potentially be utilized to detect numbers of round objects and size changes in time, such as eye pupil size or number of bacteria in a sample. Thus, we are making this software plugin freely available as open-source because we believe it will be of benefit to other colleagues both in the cephalopod biology field and also within other disciplines.
 

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@Stavros Can I get you to add your authorship name and TONMO name to a new thread in the OctopusDen > Member's Publications forum (Members' Publications) I have you included in my Google Scholar search and found a new article but can't add it to the list until you initialize an entry.

SpotMetrics: an open source image-analysis software plugin for automatic chromatophore detection and measurement
Stavros P. Hadjisolomou, George El-Haddad 2017 (PDF available from Frontiers in Physiology)
Done-- thank you for your interest. The article is in production now and the final version should be released in the next few days along with the plugin on GitHub.
 

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Octopus cyanea body patterns: A methodological approach
by Benolkin, Anne, M.S.E.S., ALASKA PACIFIC UNIVERSITY, 2016

Abstract:
Cephalopods, such as Octopus cyanea have the ability to rapidly change their overall appearance, or body pattern. Therefore, manually describing changes in body pattern in quantitative terms is important for understanding this unique and complex ability. A manually graded quantitative method addresses two questions. Are patterns of O. cyanea best described as a continuum or as discrete patterns? And what range of body patterns does O. cyanea produce? I developed a new technique, that I will call tri-shade mapping, which describes each pattern as a vector of regional intensities (light, medium, and dark). I explore a set of tri-shade mapping vectors for patterns using principal component analysis and k-means clustering analysis. This method measures components by the color displayed, and thereby avoids defining components by contrast with neighboring regions. I scored visible body CREs of n=17 octopuses in a total of 124 images. I identified two principal components of variation in body pattern. The first loaded positively on mantle bands and spots as well as alternating eye wedges. The second loaded positively on alternating mantle bands and the arms and loads negatively on the arm spots, mantle spots, and one mantle band. The two principle components also captured different aspects of overall body pattern: the first represented dark to light variation in body patterns, while the second represented contrast variation in body patterns. Possible synthetic stereotyped patterns fall along these axes in two-dimensional space but observed patterns cluster into distinct coloration types. Tri-shade mapping classifies body patterns into categories that align with Hanlon et al.?s (2009) coloration types. The new method provides a more consistent approach for future cephalopod body pattern research.

 

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Done-- thank you for your interest. The article is in production now and the final version should be released in the next few days along with the plugin on GitHub.
Article: SpotMetrics: An Open-Source Image-Analysis Software Plugin for Automatic Chromatophore Detection and Measurement
Code: available at George El-Haddad's GitHub page: GitHub - george-haddad/spotmetrics: An Open-Source Image-Analysis Software Plugin for Automatic Chromatophore Detection and Measurement
 
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Quantitative Analysis of Dynamic Body Patterning Reveals the Grammar of Visual Signals during the Reproductive Behavior of the Oval Squid Sepioteuthis lessoniana
Chun-Yen Lin, Yueh-Chun Tsai, Chuan-Chin Chiao 2017 (Full Article)
Cephalopods use a diverse range of body patterns for visual communication. Each pattern is composed of several distinct chromatic components that are under neural control and are expressed dynamically. In the oval squid Sepioteuthis lessoniana, males use distinct body patterns to interact with females and other males at the spawning site. To systematically examine their visual signals during reproductive behavior, an ethogram of 27 body pattern components produced by S. lessoniana was observed in both the wild and captivity; these were then characterized. Five behaviors were commonly seen among these reproductively active squids, namely parallel swimming, male guarding, male-male fighting, male-parallel mating, and male-upturn mating. Each behavior was found to be composed of the expression in a temporal sequence of different chromatic components. By analyzing the dynamic body patterning time series associated with each behavior, it was found that a certain subset of components was expressed simultaneously or sequentially in response to conspecifics. Importantly, the results not only revealed that each behavior is composed of multiple chromatic components, but the findings also showed that each component is often associated with multiple behaviors. To gain insight into the visual communication associated with each behavior in terms of the body patterning's key components, the co-expression frequencies of two or more components at any moment in time were calculated in order to assess uniqueness when distinguishing one behavior from another. This approach identified the minimum set of key components that, when expressed together, represents an unequivocal visual communication signal. While the interpretation of the signal and the associated response of the receiver during visual communication are difficult to determine, the concept of the component assembly is similar to a typical language within which individual words often have multiple meanings, but when they appeared together with other words, the message becomes unequivocal. The present study thus demonstrates that dynamic body pattering, by expressing unique sets of key components acutely, is an efficient way of communicating behavioral information between oval squids.
 

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Dynamic skin patterns in cephalopods
Martin J. How, Mark D. Norman, Julian Finn,Wen-Sung Chung, N Justin Marshall 2017 (subscription Frontiers in Physiology)

ephalopods are unrivalled in the natural world in their ability to alter their visual appearance. These mollusks have evolved a complex system of dermal units under neural, hormonal and muscular control to produce an astonishing variety of body patterns. With parallels to the pixels on a television screen, cephalopod chromatophores can be coordinated to produce dramatic, dynamic, and rhythmic displays, defined collectively here as ‘dynamic patterns’. This study examines the nature, context, and potential functions of dynamic patterns across diverse cephalopod taxa. Examples are presented for 21 species, including 11 previously unreported in the scientific literature. These range from simple flashing or flickering patterns, to highly complex passing wave patterns involving multiple skin fields.
 

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THE OLFACTORY SYSTEM OF THE EMBRYONIC COMMON CUTTLEFISH, SEPIA OFFICINALIS
Alexia Scaros 2017 (Master's Thesis PDF)
In summary, cephalopods have an unusual combination of features that are reminiscent of other more complex animals. Their olfactory sensory systems have similar complexity to those of both vertebrates, insects, and crustaceans. They also share the same bipolar OSN morphology and follow similar trends in their olfactory receptors. Their early and direct development makes cephalopods a great study specimen for describing the development of the nervous system. To gain further insights into the olfactory system of cephalopods, I have focused my research on two different chapters: Chapter 3: Histamine in the Olfactory System of Sepia officinalis Hypothesis: Histamine has been suggested as a neurotransmitter in the chemosensory systems of gastropods; therefore, I hypothesize that histamine is a neurotransmitter in a subset of olfactory sensory neurons in Sepia officinalis. Chapter 4: The Organization and Development of the Olfactory Lobe Hypothesis: Sepia officinalis have glomeruli to organize their olfactory inputs into the olfactory lobe, homologous to the glomeruli previously described in vertebrates, insects, crustaceans, and gastropods.
 

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Adaptive infrared-reflecting systems inspired by cephalopods
Chengyi Xu, George T. Stiubianu, Alon A. Gorodetsky 2018 (Science Magazine, Full article)

Abstract
Materials and systems that statically reflect radiation in the infrared region of the electromagnetic spectrum underpin the performance of many entrenched technologies, including building insulation, energy-conserving windows, spacecraft components, electronics shielding, container packaging, protective clothing, and camouflage platforms. The development of their adaptive variants, in which the infrared-reflecting properties dynamically change in response to external stimuli, has emerged as an important unmet scientific challenge. By drawing inspiration from cephalopod skin, we developed adaptive infrared-reflecting platforms that feature a simple actuation mechanism, low working temperature, tunable spectral range, weak angular dependence, fast response, stability to repeated cycling, amenability to patterning and multiplexing, autonomous operation, robust mechanical properties, and straightforward manufacturability. Our findings may open opportunities for infrared camouflage and other technologies that regulate infrared radiation.
 

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