scholarly journals Effects of Visual Cues of a Moving Model Predator on Body Patterns in Cuttlefish Sepia pharaonis

2015 ◽  
Vol 32 (4) ◽  
pp. 336 ◽  
Keyword(s):  
Visual Cues ◽  
Sepia Pharaonis ◽  
Body Patterns ◽  
Model Predator

scholarly journals Effects of early visual experience on the background preference in juvenile cuttlefish Sepia pharaonis

2012 ◽  
Vol 8 (5) ◽  
pp. 740-743 ◽  
Author(s):  
Yi-Hsin Lee ◽  
Hong Young Yan ◽  
Chuan-Chin Chiao
Keyword(s):  
Body Size ◽  
Visual Experience ◽  
Choice Experiments ◽  
Enriched Environment ◽  
Object Size ◽  
High Contrast ◽  
Sepia Pharaonis ◽  
Body Patterns ◽  
Enriched Environments

Although cuttlefish are capable of showing diverse camouflage body patterns against a variety of background substrates, whether they show background preference when given a choice of substrates is not well known. In this study, we characterized the background choice of post-embryonic cuttlefish ( Sepia pharaonis ) and examined the effects of rearing visual environments on their background preferences. Different rearing backgrounds (enriched, uniformly grey and checkerboard) were used to raise cuttlefish from eggs or hatchlings, and four sets of two-background-choice experiments (differences in contrast, shape, size and side) were conducted at day 1 and weeks 4, 8 and 12 post-hatch. Cuttlefish reared in the enriched environment preferred high-contrast backgrounds at all post-embryonic stages. In comparison, those reared in the impoverished environments (uniformly grey and checkerboard) had either reversed or delayed high-contrast background preference. In addition, cuttlefish raised on the uniformly grey background, exposed to a checkerboard briefly (0.5 or 3 h) at week 4 and tested at week 8 showed increased high-contrast background preference. Interestingly, cuttlefish in the enriched group preferred an object size similar to their body size at day 1 and week 4, but changed this preference to smaller objects at week 12. These results suggest that high-contrast backgrounds may be more adaptive for juvenile cuttlefish, and visually enriched environments are important for the development of these background preference behaviours.

scholarly journals Cuttlefish dynamic camouflage: responses to substrate choice and integration of multiple visual cues

2009 ◽  
Vol 277 (1684) ◽  
pp. 1031-1039 ◽  
Author(s):  
Justine J. Allen ◽  
Lydia M. Mäthger ◽  
Alexandra Barbosa ◽  
Kendra C. Buresch ◽  
Emilia Sogin ◽  
...  
Keyword(s):  
Visual Cues ◽  
Substrate Preference ◽  
Artificial Substrates ◽  
Energy Costs ◽  
Evolutionary Response ◽  
Substrate Choice ◽  
Left And Right ◽  
Body Patterns ◽  
Insight Into ◽  
Body Pattern

Prey camouflage is an evolutionary response to predation pressure. Cephalopods have extensive camouflage capabilities and studying them can offer insight into effective camouflage design. Here, we examine whether cuttlefish, Sepia officinalis , show substrate or camouflage pattern preferences. In the first two experiments, cuttlefish were presented with a choice between different artificial substrates or between different natural substrates. First, the ability of cuttlefish to show substrate preference on artificial and natural substrates was established. Next, cuttlefish were offered substrates known to evoke three main camouflage body pattern types these animals show: Uniform or Mottle (function by background matching); or Disruptive. In a third experiment, cuttlefish were presented with conflicting visual cues on their left and right sides to assess their camouflage response. Given a choice between substrates they might encounter in nature, we found no strong substrate preference except when cuttlefish could bury themselves. Additionally, cuttlefish responded to conflicting visual cues with mixed body patterns in both the substrate preference and split substrate experiments. These results suggest that differences in energy costs for different camouflage body patterns may be minor and that pattern mixing and symmetry may play important roles in camouflage.

scholarly journals Contrasting stripes are a widespread feature of group living in birds, mammals and fishes

2020 ◽  
Author(s):  
Juan J. Negro ◽  
Jorge Doña ◽  
M. del Carmen Blázquez ◽  
Airam Rodríguez ◽  
James E. Herbert-Read ◽  
...  
Keyword(s):  
Visual Cues ◽  
Group Living ◽  
Visual Channel ◽  
Social Species ◽  
Behavioral Rules ◽  
Directional Movement ◽  
Collective Movements ◽  
Logistic Regressions ◽  
Body Patterns ◽  
Solitary Species

AbstractGrouping is a widespread form of predator defense, with individuals in groups often performing evasive collective movements in response to predators’ attacks. Individuals in these groups use behavioral rules to coordinate their movements, with visual cues about neighbors’ positions and orientations informing movement decisions. Although the exact visual cues individuals use to coordinate their movements with neighbors have not yet been decoded, some studies have suggested that stripes, lines or other body patterns may act as conspicuous conveyors of movement information that could promote coordinated group movement, or promote dazzle camouflage, thereby confusing predators. We used phylogenetic logistic regressions to test whether the contrasting achromatic stripes present in four different taxa vulnerable to predation, including species within two orders of birds (Anseriformes and Charadriiformes), a suborder of Artiodactyla (the ruminants) and several orders of marine fish (predominantly Perciformes) were associated with group living. Contrasting patterns were significantly more prevalent in social species, and tended to be absent in solitary species or species less vulnerable to predation. We suggest that stripes taking the form of light-colored lines on dark backgrounds, or vice versa, provide a widespread mechanism across taxa that serves either to inform conspecifics of neighbors’ directional movement, or to confuse predators, when moving in groups. Detection and processing of patterns and of motion in the visual channel is essentially colourblind. That diverse animal taxa with widely different vision systems (including di-, tri- and tetrachromats) appear to have converged on a similar use of achromatic patterns is therefore expected given signal-detection theory. This hypothesis would explain the convergent evolution of conspicuous achromatic patterns as an antipredator mechanism in numerous vertebrate species.

scholarly journals Contrasting stripes are a widespread feature of group living in birds, mammals and fishes

2020 ◽  
Vol 287 (1936) ◽  
pp. 20202021
Author(s):  
Juan J. Negro ◽  
Jorge Doña ◽  
M. Carmen Blázquez ◽  
Airam Rodríguez ◽  
James E. Herbert-Read ◽  
...  
Keyword(s):  
Visual Cues ◽  
Signal Detection Theory ◽  
Group Living ◽  
Visual Channel ◽  
Social Species ◽  
Collective Movements ◽  
Logistic Regressions ◽  
Body Patterns ◽  
Predator Defence ◽  
Solitary Species

Grouping is a widespread form of predator defence, with individuals in groups often performing evasive collective movements in response to attack by predators. Individuals in these groups use behavioural rules to coordinate their movements, with visual cues about neighbours’ positions and orientations often informing movement decisions. Although the exact visual cues individuals use to coordinate their movements with neighbours have not yet been decoded, some studies have suggested that stripes, lines, or other body patterns may act as conspicuous conveyors of movement information that could promote coordinated group movement, or promote dazzle camouflage, thereby confusing predators. We used phylogenetic logistic regressions to test whether the contrasting achromatic stripes present in four different taxa vulnerable to predation, including species within two orders of birds (Anseriformes and Charadriiformes), a suborder of Artiodactyla (the ruminants), and several orders of marine fishes (predominantly Perciformes) were associated with group living. Contrasting patterns were significantly more prevalent in social species, and tended to be absent in solitary species or species less vulnerable to predation. We suggest that stripes taking the form of light-coloured lines on dark backgrounds, or vice vers a , provide a widespread mechanism across taxa that either serves to inform conspecifics of neighbours' movements, or to confuse predators, when moving in groups. Because detection and processing of patterns and of motion in the visual channel is essentially colour-blind, diverse animal taxa with widely different vision systems (including mono-, di-, tri-, and tetrachromats) appear to have converged on a similar use of achromatic patterns, as would be expected given signal-detection theory. This hypothesis would explain the convergent evolution of conspicuous achromatic patterns as an antipredator mechanism in numerous vertebrate species.

scholarly journals Cephalopod dynamic camouflage: bridging the continuum between background matching and disruptive coloration

2008 ◽  
Vol 364 (1516) ◽  
pp. 429-437 ◽  
Author(s):  
R.T Hanlon ◽  
C.-C Chiao ◽  
L.M Mäthger ◽  
A Barbosa ◽  
K.C Buresch ◽  
...  
Keyword(s):  
Visual Cues ◽  
The Body ◽  
Background Matching ◽  
Disruptive Coloration ◽  
Size Contrast ◽  
Body Patterns ◽  
Three Body ◽  
Web Archive ◽  
Body Pattern ◽  
The Continuum

Individual cuttlefish, octopus and squid have the versatile capability to use body patterns for background matching and disruptive coloration. We define—qualitatively and quantitatively—the chief characteristics of the three major body pattern types used for camouflage by cephalopods: uniform and mottle patterns for background matching, and disruptive patterns that primarily enhance disruptiveness but aid background matching as well. There is great variation within each of the three body pattern types, but by defining their chief characteristics we lay the groundwork to test camouflage concepts by correlating background statistics with those of the body pattern. We describe at least three ways in which background matching can be achieved in cephalopods. Disruptive patterns in cuttlefish possess all four of the basic components of ‘disruptiveness’, supporting Cott's hypotheses, and we provide field examples of disruptive coloration in which the body pattern contrast exceeds that of the immediate surrounds. Based upon laboratory testing as well as thousands of images of camouflaged cephalopods in the field (a sample is provided on a web archive), we note that size, contrast and edges of background objects are key visual cues that guide cephalopod camouflage patterning. Mottle and disruptive patterns are frequently mixed, suggesting that background matching and disruptive mechanisms are often used in the same pattern.

Supporting the Use of Rudimentary Vocalizations

2014 ◽  
Vol 23 (3) ◽  
pp. 132-139 ◽  
Author(s):  
Lauren Zubow ◽  
Richard Hurtig
Keyword(s):  
Rett Syndrome ◽  
Visual Cues ◽  
Acoustic Analysis ◽  
Eye Gaze ◽  
Research Question ◽  
Primary Research ◽  
Multiple Modalities ◽  
Face To Face ◽  
Perceptual Judgments ◽  
The Face

Children with Rett Syndrome (RS) are reported to use multiple modalities to communicate although their intentionality is often questioned (Bartolotta, Zipp, Simpkins, & Glazewski, 2011; Hetzroni & Rubin, 2006; Sigafoos et al., 2000; Sigafoos, Woodyatt, Tuckeer, Roberts-Pennell, & Pittendreigh, 2000). This paper will present results of a study analyzing the unconventional vocalizations of a child with RS. The primary research question addresses the ability of familiar and unfamiliar listeners to interpret unconventional vocalizations as “yes” or “no” responses. This paper will also address the acoustic analysis and perceptual judgments of these vocalizations. Pre-recorded isolated vocalizations of “yes” and “no” were presented to 5 listeners (mother, father, 1 unfamiliar, and 2 familiar clinicians) and the listeners were asked to rate the vocalizations as either “yes” or “no.” The ratings were compared to the original identification made by the child's mother during the face-to-face interaction from which the samples were drawn. Findings of this study suggest, in this case, the child's vocalizations were intentional and could be interpreted by familiar and unfamiliar listeners as either “yes” or “no” without contextual or visual cues. The results suggest that communication partners should be trained to attend to eye-gaze and vocalizations to ensure the child's intended choice is accurately understood.

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