1
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Tong H, Shao G, Wang L, Li J, Wang T, Zhang L, Lv Y, Ye F, Fu C, Jin Y. Association of a single amino acid replacement with dorsal pigmentation in a lizard from the Qinghai-Tibetan Plateau. Int J Biol Macromol 2023; 242:124907. [PMID: 37230451 DOI: 10.1016/j.ijbiomac.2023.124907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 05/08/2023] [Accepted: 05/13/2023] [Indexed: 05/27/2023]
Abstract
Reptiles can evolve adaptive colors in different environments, but relatively little is known about the genetic mechanisms. Here, we identified the MC1R gene and its association with intraspecific color variation in the lizard Phrynocephalus erythrurus. Analysis of the MC1R sequence in 143 individuals from dark South Qiangtang Plateau (SQP) and light North Qiangtang plateau (NQP) populations, revealed two amino acid sites that showed significant differences in frequency between two areas. One SNP, corresponding to Glu183Lys residue, was found to be a highly significant outlier and differentially fixed for SQP and NQP populations. This residue is located in an extracellular area in the second small extracellular loop within the secondary structure of MC1R, which represents an "attachment pocket" part of the 3D structure. Cytological expression of MC1R alleles with the Glu183Lys replacement showed a 39 % increase in intracellular agonist-induced cyclic AMP levels and a 23.18 % greater cell surface expression of MC1R protein in the SQP relative to the NQP allele. Further in silico 3D modeling and in vitro binding experiments indicated a higher MC1R-α-MSH binding for the SQP allele, and elevated melanin synthesis. We provide an overview of how a single amino acid replacement leads to fundamental changes in MC1R function, and hence shapes variation in dorsal pigmentation in lizards from different environments.
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Affiliation(s)
- Haojie Tong
- College of Life Sciences, China Jiliang University, Hangzhou 310018, PR China
| | - Gang Shao
- College of Life Sciences, China Jiliang University, Hangzhou 310018, PR China
| | - Leijie Wang
- College of Life Sciences, China Jiliang University, Hangzhou 310018, PR China
| | - Jiasheng Li
- College of Life Sciences, China Jiliang University, Hangzhou 310018, PR China
| | - Tao Wang
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Lun Zhang
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Yudie Lv
- College of Life Sciences, China Jiliang University, Hangzhou 310018, PR China
| | - Fei Ye
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Caiyun Fu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Yuanting Jin
- College of Life Sciences, China Jiliang University, Hangzhou 310018, PR China.
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2
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Gould GG, Barba-Escobedo PA, Horton RE, Daws LC. High Affinity Decynium-22 Binding to Brain Membrane Homogenates and Reduced Dorsal Camouflaging after Acute Exposure to it in Zebrafish. Front Pharmacol 2022; 13:841423. [PMID: 35754508 PMCID: PMC9218599 DOI: 10.3389/fphar.2022.841423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 03/29/2022] [Indexed: 11/13/2022] Open
Abstract
Organic cation transporters (OCTs) are expressed in the mammalian brain, kidney, liver, placenta, and intestines, where they facilitate the transport of cations and other substrates between extracellular fluids and cells. Despite increasing reliance on ectothermic vertebrates as alternative toxicology models, properties of their OCT homologs transporting many drugs and toxins remain poorly characterized. Recently, in zebrafish (Danio rerio), two proteins with functional similarities to human OCTs were shown to be highly expressed in the liver, kidney, eye, and brain. This study is the first to characterize in vivo uptake to the brain and the high-affinity brain membrane binding of the mammalian OCT blocker 1-1'-diethyl-2,2'cyanine iodide (decynium-22 or D-22) in zebrafish. Membrane saturation binding of [3H] D-22 in pooled zebrafish whole brain versus mouse hippocampal homogenates revealed a high-affinity binding site with a KD of 5 ± 2.5 nM and Bmax of 1974 ± 410 fmol/mg protein in the zebrafish brain, and a KD of 3.3 ± 2.3 and Bmax of 704 ± 182 fmol/mg protein in mouse hippocampus. The binding of [3H] D-22 to brain membrane homogenates was partially blocked by the neurotoxic cation 1-methyl-4-phenylpyridinium (MPP+), a known OCT substrate. To determine if D-22 bath exposures reach the brain, zebrafish were exposed to 25 nM [3H] D-22 for 10 min, and 736 ± 68 ng/g wet weight [3H] D-22 was bound. Acute behavioral effects of D-22 in zebrafish were characterized in two anxiety-relevant tests. In the first cohort of zebrafish, 12.5, 25, or 50 mg/L D-22 had no effect on their height in the dive tank or entries and time spent in white arms of a light/dark plus maze. By contrast, 25 mg/L buspirone increased zebrafish dive tank top-dwelling (p < 0.05), an anticipated anxiolytic effect. However, a second cohort of zebrafish treated with 50 mg/L D-22 made more white arm entries, and females spent more time in white than controls. Based on these findings, it appears that D-22 bath treatments reach the zebrafish brain and have partial anxiolytic properties, reducing anti-predator dorsal camouflaging, without increasing vertical exploration. High-affinity binding of [3H] D-22 in zebrafish brain and mouse brain was similar, with nanomolar affinity, possibly at conserved OCT site(s).
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Affiliation(s)
- Georgianna G Gould
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States.,Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Priscilla A Barba-Escobedo
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States.,Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Rebecca E Horton
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States.,Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Lynette C Daws
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States.,Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States.,Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
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3
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Wuthrich KL, Nagel A, Swierk L. Rapid Body Color Change Provides Lizards with Facultative Crypsis in the Eyes of Their Avian Predators. Am Nat 2021; 199:277-290. [DOI: 10.1086/717678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Kelly Lin Wuthrich
- Department of Biological Sciences, Binghamton University, State University of New York, Binghamton, New York 13902
| | - Amber Nagel
- Department of Chemical Engineering, University of Oklahoma, Norman, Oklahoma 73019
| | - Lindsey Swierk
- Department of Biological Sciences, Binghamton University, State University of New York, Binghamton, New York 13902
- School of the Environment, Yale University, New Haven, Connecticut 06511; and Amazon Conservatory for Tropical Studies, Iquitos, Loreto 16001, Perú
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4
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Wan L, Liu Z, Wang T, Yang M, Li J, Sun H, Niu C, Zhao W, Jin Y. Camouflage versus running performance as strategies against predation in a lizard inhabiting different habitats. Ecol Evol 2021; 11:17409-17416. [PMID: 34938517 PMCID: PMC8668757 DOI: 10.1002/ece3.8374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 10/30/2021] [Accepted: 11/02/2021] [Indexed: 11/13/2022] Open
Abstract
Running speed and camouflage are associated with the foraging and anti-predator abilities of animals. The toad-headed lizard, Phrynocephalus versicolor, has evolved a darker dorsal color in melanistic habitats and maintained a lighter color in adjacent, non-melanistic habitats. We test the hypothesis that lizards have weaker running speed on well-matching backgrounds than on less matching backgrounds. We used lizard models to compare the predation pressure, while the running speed of dark and light lizards were compared in field tunnels using a video recording method. Our results indicated that both the dark lizards in melanistic Heishankou (HSK) and the light lizards in non-melanistic Guazhou (GZ) face lower predation pressure than potential color-background unmatched lizards. The light lizards have a potentially higher running speed than darker lizards in melanistic habitats, which implies that substrate color matching populations with benefits of camouflage might have lower anti-predation pressure, and the costs of investment in melanin production may reduce running capacity.
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Affiliation(s)
- Lixia Wan
- College of Life SciencesNorthwest Normal UniversityLanzhouChina
| | - Zhenxia Liu
- College of Life SciencesNorthwest Normal UniversityLanzhouChina
- College of Life SciencesChina Jiliang UniversityHangzhouChina
| | - Tao Wang
- College of life sciences and medicineZhejiang Sci‐Tech UniversityHangzhouChina
| | - Minglu Yang
- College of Life SciencesNorthwest Normal UniversityLanzhouChina
| | - Jiasheng Li
- College of Life SciencesChina Jiliang UniversityHangzhouChina
| | - Hui Sun
- College of Life SciencesChina Jiliang UniversityHangzhouChina
| | - Chenkai Niu
- College of Life SciencesLanzhou UniversityLanzhouChina
| | - Wei Zhao
- College of Life SciencesLanzhou UniversityLanzhouChina
| | - Yuanting Jin
- College of Life SciencesChina Jiliang UniversityHangzhouChina
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5
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Kokita T, Ueno K, Yamasaki YY, Matsuda M, Tabata R, Nagano AJ, Mishina T, Watanabe K. Gudgeon fish with and without genetically determined countershading coexist in heterogeneous littoral environments of an ancient lake. Ecol Evol 2021; 11:13283-13294. [PMID: 34646469 PMCID: PMC8495823 DOI: 10.1002/ece3.8050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/02/2021] [Accepted: 08/09/2021] [Indexed: 11/16/2022] Open
Abstract
Countershading, characterized by a darker dorsal surface and lighter ventral surface, is common among many animals. This dorsoventral pigment polarity is often thought to be adaptive coloration for camouflage. By contrast, noncountershaded (melanistic) morphs often occur within a species due to genetic color polymorphism in terrestrial animals. However, the polymorphism with either countershaded or melanistic morphs is poorly known in wild aquatic animals. This study explored the genetic nature of diverged color morphs of a lineage of gudgeon fish (genus Sarcocheilichthys) in the ancient Lake Biwa and propose this system as a novel model for testing hypotheses of functional aspects of countershading and its loss in aquatic environments. This system harbors two color morphs that have been treated taxonomically as separate species; Sarcocheilichthys variegatus microoculus which occurs throughout the littoral zone and Sarcocheilichthys biwaensis which occurs in and around rocky areas. First, we confirmed that the divergence of dorsoventral color patterns between the two morphs is under strict genetic control at the levels of chromatophore distribution and melanin-related gene expression under common garden rearing. The former morph displayed sharp countershading coloration, whereas the latter morph exhibited a strong tendency toward its loss. The crossing results indicated that this divergence was likely controlled by a single locus in a two-allele Mendelian inheritance pattern. Furthermore, our population genomic and genome-wide association study analyses detected no genome-wide divergence between the two morphs, except for one region near a locus that may be associated with the color divergence. Thus, these morphs are either in a state of intraspecific color polymorphism or two incipient species. Evolutionary forces underlying this polymorphism appear to be associated with heterogeneous littoral environments in this lake. Future ecological genomic research will provide insight into adaptive functions of this widespread coloration, including the eco-evolutionary drivers of its loss, in the aquatic world.
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Affiliation(s)
- Tomoyuki Kokita
- Faculty of Marine Science and TechnologyFukui Prefectural UniversityObamaJapan
| | - Kohtaro Ueno
- Faculty of Marine Science and TechnologyFukui Prefectural UniversityObamaJapan
| | | | | | | | - Atsushi J. Nagano
- Faculty of AgricultureRyukoku UniversityOtsuJapan
- Institute for Advanced BiosciencesKeio UniversityTsuruokaJapan
| | - Tappei Mishina
- Laboratory for Chromosome SegregationRIKEN Center for Biosystems Dynamics ResearchKobeJapan
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6
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Mavrovouna V, Penacchio O, Allen WL. Orienting to the sun improves camouflage for bilaterally symmetrical prey. Biol J Linn Soc Lond 2021. [DOI: 10.1093/biolinnean/blab130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
Here, we investigate the camouflage consequences of animal orientation behaviour. Shadows can be a conspicuous cue to the presence of prey. For bilaterally symmetrical animals, light field modelling indicates that camouflage will be improved when an animal orients its longitudinal axis directly towards or away from the sun, because the appearance of shadows is minimized. We test this prediction with a field predation experiment, in which wild birds hunt for artificial camouflaged prey oriented with the longitudinal axis either parallel or perpendicular to the sun. We find that prey oriented parallel to the sun are 3.93 times more likely to survive than prey oriented perpendicular to the sun. This result demonstrates the strong orientation dependence of camouflage. Given the dramatic difference in survival of prey with different orientations, we suggest that camouflage should be investigated as an important determinant of the positional behaviour of animals.
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Affiliation(s)
- Veronica Mavrovouna
- Department of Biosciences, Swansea University, Singleton Campus, Swansea SA2 8PP, UK
| | - Olivier Penacchio
- School of Psychology and Neuroscience, University of St Andrews, South Street, St Andrews, Fife KY16 9JP, UK
| | - William L Allen
- Department of Biosciences, Swansea University, Singleton Campus, Swansea SA2 8PP, UK
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7
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Caro T, Koneru M. Towards an ecology of protective coloration. Biol Rev Camb Philos Soc 2020; 96:611-641. [PMID: 33258554 DOI: 10.1111/brv.12670] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 11/05/2020] [Accepted: 11/09/2020] [Indexed: 12/15/2022]
Abstract
The strategies underlying different forms of protective coloration are well understood but little attention has been paid to the ecological, life-history and behavioural circumstances under which they evolve. While some comparative studies have investigated the ecological correlates of aposematism, and background matching, the latter particularly in mammals, few have examined the ecological correlates of other types of protective coloration. Here, we first outline which types of defensive coloration strategies may be exhibited by the same individual; concluding that many protective coloration mechanisms can be employed simultaneously, particularly in conjunction with background matching. Second, we review the ecological predictions that have been made for each sort of protective coloration mechanism before systematically surveying phylogenetically controlled comparative studies linking ecological and social variables to antipredator defences that involve coloration. We find that some a priori predictions based on small-scale empirical studies and logical arguments are indeed supported by comparative data, especially in relation to how illumination affects both background matching and self-shadow concealment through countershading; how body size is associated with countershading, motion dazzle, flash coloration and aposematism, although only in selected taxa; how immobility may promote background matching in ambush predators; and how mobility may facilitate motion dazzle. Examination of nearly 120 comparative tests reveals that many focus on ecological variables that have little to do with predictions derived from antipredator defence theory, and that broad-scale ecological studies of defence strategies that incorporate phylogenetics are still very much in their infancy. We close by making recommendations for future evolutionary ecological research.
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Affiliation(s)
- Tim Caro
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, U.K.,Center for Population Biology, University of California, Davis, CA, 95616, U.S.A
| | - Manisha Koneru
- Department of Evolution and Ecology, University of California, Davis, CA, 95616, U.S.A
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8
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Fiedler T, Verstegen T. Fibre-Reinforced Composite for Protection against Shark Bites. MATERIALS (BASEL, SWITZERLAND) 2020; 13:ma13225065. [PMID: 33182725 PMCID: PMC7696924 DOI: 10.3390/ma13225065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/05/2020] [Accepted: 11/06/2020] [Indexed: 06/11/2023]
Abstract
The number of shark attacks resulting in fatalities and severe injuries has increased steadily over recent years. This is mainly attributed to a growing population participating in ocean sports such as swimming, diving, and surfing. To mitigate the severity of shark attacks, the current study presents a novel fibre-reinforced composite for bite protection. This material is intended for integration into neoprene wetsuits, e.g., in the form of protective pads. A suitable material must be able to withstand significant bite forces, which are concentrated within a small contact area at the tips of the shark teeth. At the same time, the material should not hinder the complex motion sequences of aquatic sports. To this end, a novel fibre-reinforced composite was created by integrating Kevlar fibres into an elastic matrix. Uni-axial testing using shark teeth replicas was conducted on a specially designed test rig to quantify the effectiveness of the novel protective material.
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9
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Galloway JAM, Green SD, Stevens M, Kelley LA. Finding a signal hidden among noise: how can predators overcome camouflage strategies? Philos Trans R Soc Lond B Biol Sci 2020; 375:20190478. [PMID: 32420842 PMCID: PMC7331011 DOI: 10.1098/rstb.2019.0478] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Substantial progress has been made in the past 15 years regarding how prey use a variety of visual camouflage types to exploit both predator visual processing and cognition, including background matching, disruptive coloration, countershading and masquerade. By contrast, much less attention has been paid to how predators might overcome these defences. Such strategies include the evolution of more acute senses, the co-opting of other senses not targeted by camouflage, changes in cognition such as forming search images, and using behaviours that change the relationship between the cryptic individual and the environment or disturb prey and cause movement. Here, we evaluate the methods through which visual camouflage prevents detection and recognition, and discuss if and how predators might evolve, develop or learn counter-adaptations to overcome these. This article is part of the theme issue ‘Signal detection theory in recognition systems: from evolving models to experimental tests'.
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Affiliation(s)
- James A M Galloway
- Centre for Ecology and Conservation, University of Exeter (Penryn Campus), Cornwall TR10 9FE, UK
| | - Samuel D Green
- Centre for Ecology and Conservation, University of Exeter (Penryn Campus), Cornwall TR10 9FE, UK
| | - Martin Stevens
- Centre for Ecology and Conservation, University of Exeter (Penryn Campus), Cornwall TR10 9FE, UK
| | - Laura A Kelley
- Centre for Ecology and Conservation, University of Exeter (Penryn Campus), Cornwall TR10 9FE, UK
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10
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Donohue CG, Hemmi JM, Kelley JL. Countershading enhances camouflage by reducing prey contrast. Proc Biol Sci 2020; 287:20200477. [PMID: 32396802 DOI: 10.1098/rspb.2020.0477] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A three-dimensional body shape is problematic for camouflage because overhead lighting produces a luminance gradient across the body's surface. Countershading, a form of patterning where animals are darkest on their uppermost surface, is thought to counteract this luminance gradient and enhance concealment, but the mechanisms of protection remain unclear. Surprisingly, no study has examined how countershading alters prey contrast, or investigated how the presence of a dorsoventral luminance gradient affects detection under controlled viewing conditions. It has also been suggested that the direction of the dorsoventral luminance gradient (darkest or lightest on top) may interfere with predators' abilities to resolve prey's three-dimensional shape, yet this intriguing idea has never been tested. We used live fish predators (western rainbowfish, Melanotaenia australis) and computer-generated prey images to compare the detectability of uniformly pigmented (i.e. non-countershaded) prey with that of optimally countershaded prey of varying contrasts against the background. Optimally countershaded prey were difficult for predators to detect, and the probability and speed of detection depended on prey luminance contrast with the background. In comparison, non-countershaded prey were always highly detectable, even though their average luminance closely matched the luminance of the background. Our findings suggest that uniformly pigmented three-dimensional prey are highly conspicuous to predators because overhead lighting increases luminance contrast between different body parts or between the body and the background. We found no evidence for the notion that countershading interferes with predator perception of three-dimensional form.
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Affiliation(s)
- Callum G Donohue
- School of Biological Sciences, The University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Jan M Hemmi
- School of Biological Sciences, The University of Western Australia, Crawley, Western Australia 6009, Australia.,The UWA Oceans Institute, The University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Jennifer L Kelley
- School of Biological Sciences, The University of Western Australia, Crawley, Western Australia 6009, Australia.,The UWA Oceans Institute, The University of Western Australia, Crawley, Western Australia 6009, Australia
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11
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Hodge JR, Santini F, Wainwright PC. Colour dimorphism in labrid fishes as an adaptation to life on coral reefs. Proc Biol Sci 2020; 287:20200167. [PMID: 32183627 PMCID: PMC7126040 DOI: 10.1098/rspb.2020.0167] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 03/02/2020] [Indexed: 12/23/2022] Open
Abstract
Conspicuous coloration displayed by animals that express sexual colour dimorphism is generally explained as an adaptation to sexual selection, yet the interactions and relative effects of selective forces influencing colour dimorphism are largely unknown. Qualitatively, colour dimorphism appears more pronounced in marine fishes that live on coral reefs where traits associated with strong sexual selection are purportedly more common. Using phylogenetic comparative analysis, we show that wrasses and parrotfishes exclusive to coral reefs are the most colour dimorphic, but surprisingly, the effect of habitat is not influenced by traits associated with strong sexual selection. Rather, habitat-specific selective forces, including clear water and structural refuge, promote the evolution of pronounced colour dimorphism that manifests colours less likely to be displayed in other habitats. Our results demonstrate that environmental context ultimately determines the evolution of conspicuous coloration in colour-dimorphic labrid fishes, despite other influential selective forces.
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Affiliation(s)
- J R Hodge
- Department of Evolution and Ecology, University of California, Davis, CA 95616, USA
| | - F Santini
- Department of Evolution and Ecology, University of California, Davis, CA 95616, USA
| | - P C Wainwright
- Department of Evolution and Ecology, University of California, Davis, CA 95616, USA
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12
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Wojan EM, Carreiro NC, Clendenen DA, Neldner HM, Castillo C, Bertram SM, Kolluru GR. The effects of commonly used anaesthetics on colour measurements across body regions in the poeciliid fish, Girardinus metallicus. JOURNAL OF FISH BIOLOGY 2019; 95:1320-1330. [PMID: 31515796 DOI: 10.1111/jfb.14138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 09/12/2019] [Indexed: 06/10/2023]
Abstract
The effects of common anaesthetics on the hue, saturation and brightness measurements of the poeciliid fish Girardinus metallicus were investigated in two experiments. For both experiments the coloration of four body regions was measured from digital images of the same males obtained under three conditions: (1) control (in a water-filled chamber); (2) anaesthetised with MS-222; and (3) anaesthetised with eugenol (clove oil). In experiment 1 anaesthetised fish were photographed out of water. In experiment 2 all photographs were taken in a water-filled chamber. Anaesthetics altered coloration in both experiments. In the more methodologically consistent experiment 2 we found significantly different hue, increased saturation and decreased brightness in anaesthetic v. control conditions, consistent with darkening caused by the anaesthetics. The body regions differed in coloration consistent with countershading but did not differentially change in response to anaesthesia. These findings suggest that photographing fish in a water-filled chamber without anaesthetic is preferable for obtaining digital images for colour analysis and that multiple body regions of fish should be measured when assessing coloration patterns meaningful in behavioural contexts, to account for the gradients caused by countershading. We are encouraged that some researchers employ such methods already and caution against using anaesthetics except when absolutely necessary for immobilisation.
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Affiliation(s)
- Erin M Wojan
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, California, USA
| | - Nalana C Carreiro
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, California, USA
| | - David A Clendenen
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, California, USA
| | - Heather M Neldner
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, California, USA
| | - Crystal Castillo
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, California, USA
| | - Susan M Bertram
- Biology Department, Carleton University, Ottawa, Ontario, Canada
| | - Gita R Kolluru
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, California, USA
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13
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Tong H, Li J, Wo Y, Shao G, Zhao W, Aguilar‐Gómez D, Jin Y. Effects of substrate color on intraspecific body color variation in the toad-headed lizard, Phrynocephalus versicolor. Ecol Evol 2019; 9:10253-10262. [PMID: 31624549 PMCID: PMC6787858 DOI: 10.1002/ece3.5545] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 07/12/2019] [Accepted: 07/16/2019] [Indexed: 12/19/2022] Open
Abstract
Diversity in animal coloration is generally associated with adaptation to their living habitats, ranging from territorial display and sexual selection to predation or predation avoidance, and thermoregulation. However, the mechanism underlying color variation in toad-headed Phrynocephalus lizards remains poorly understood. In this study, we investigated the population color variation of Phrynocephalus versicolor. We found that lizards distributed in dark substrate have darker dorsal coloration (melanic lizards) than populations living in light substrates. This characteristic may improve their camouflage effectiveness. A reciprocal substrate translocation experiment was conducted to clarify the potential role of morphological adaptation and physiological plasticity of this variation. Spectrometry technology and digital photography were used to quantify the color variation of the above-mentioned melanic and nonmelanic P. versicolor populations and their native substrate. Additionally, substrate color preference in both populations was investigated with choice experiments. Our results indicate that the melanic and nonmelanic populations with remarkable habitat color difference were significantly different on measured reflectance, luminance, and RGB values. Twenty-four hours, 30 days, and 60 days of substrate translocation treatment had little effects on dorsal color change. We also found that melanic lizards choose to live in dark substrate, while nonmelanic lizards have no preference for substrate color. In conclusion, our results support that the dorsal coloration of P. versicolor, associated with substrate color, is likely a morphological adaptation rather than phenotypic plasticity.
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Affiliation(s)
- Haojie Tong
- College of Life SciencesChina Jiliang UniversityHangzhouChina
| | - Jiasheng Li
- College of Life SciencesChina Jiliang UniversityHangzhouChina
| | - Yubin Wo
- College of Life SciencesChina Jiliang UniversityHangzhouChina
| | - Gang Shao
- College of Life SciencesChina Jiliang UniversityHangzhouChina
| | - Wei Zhao
- School of Life SciencesLanzhou UniversityLanzhouChina
| | | | - Yuanting Jin
- College of Life SciencesChina Jiliang UniversityHangzhouChina
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