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Zeil J. Views from 'crabworld': the spatial distribution of light in a tropical mudflat. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2023; 209:859-876. [PMID: 37460846 PMCID: PMC10643439 DOI: 10.1007/s00359-023-01653-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/18/2023] [Accepted: 06/29/2023] [Indexed: 11/14/2023]
Abstract
Natural scene analysis has been extensively used to understand how the invariant structure of the visual environment may have shaped biological image processing strategies. This paper deals with four crucial, but hitherto largely neglected aspects of natural scenes: (1) the viewpoint of specific animals; (2) the fact that image statistics are not independent of the position within the visual field; (3) the influence of the direction of illumination on luminance, spectral and polarization contrast in a scene; and (4) the biologically relevant information content of natural scenes. To address these issues, I recorded the spatial distribution of light in a tropical mudflat with a spectrographic imager equipped with a polarizing filter in an attempt to describe quantitatively the visual environment of fiddler crabs. The environment viewed by the crabs has a distinct structure. Depending on the position of the sun, the luminance, the spectral composition, and the polarization characteristics of horizontal light distribution are not uniform. This is true for both skylight and for reflections from the mudflat surface. The high-contrast feature of the line of horizon dominates the vertical distribution of light and is a discontinuity in terms of luminance, spectral distribution and of image statistics. On a clear day, skylight intensity increases towards the horizon due to multiple scattering, and its spectral composition increasingly resembles that of sunlight. Sky-substratum contrast is highest at short wavelengths. I discuss the consequences of this extreme example of the topography of vision for extracting biologically relevant information from natural scenes.
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Affiliation(s)
- Jochen Zeil
- Research School of Biology, Australian National University, P.O. Box 475, Canberra, ACT, 2601, Australia.
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2
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Tina FW, Muramatsu D. Males signal their breeding burrow characteristics to females in the fiddler crab Austruca perplexa. BEHAVIOUR 2022. [DOI: 10.1163/1568539x-bja10165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Females often choose mates based on their courtship signals. Males may signal their heritable genetic quality, defended resources, or parental care efforts; however, the reasons why females choose males based on their signals are often not clear. Here, we show that, in the fiddler crab Austruca perplexa, male signals (major-claw waving rates) were correlated with important characteristics of their defended resources (width and depth of breeding burrows). By using the male signals, females may be able to roughly predict the burrow quality and decide whether to enter and check the burrow characteristics. The signals are predicted to be honest because the female’s final decision is based on burrow quality. Since females can reject males if their burrow quality is insufficient for breeding, the courtship efforts of deceptive males will be dismissed. The honesty of the signals is beneficial for both sexes and thus easily evolved in their signalling system.
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Affiliation(s)
- Fahmida Wazed Tina
- Faculty of Science and Technology, Nakhon Si Thammarat Rajabhat University, Tha Ngio, Nakhon Si Thammarat 80280, Thailand
| | - Daisuke Muramatsu
- , Nara University of Education, Takabatake-cho, Nara, 630-8528, Japan
- Wildlife Research Center, Kyoto University, 2-24 Sekiden, Tanaka, Sakyo, Kyoto 606-8203, Japan
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3
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Peters RA, De Jong J, Ramos JA. Movement-based signalling by four species of dragon lizard (family Agamidae) from the Kimberley region of Western Australia. AUST J ZOOL 2022. [DOI: 10.1071/zo21047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Communication signals underpin the social lives of animals, from species recognition to mate selection and territory defense. Animal signals are diverse in structure between and within species, with the diversity reflecting interacting factors of shared evolutionary history, constraints imposed on senders and receivers and the ecological context in which signalling takes place. The dragon lizards of Australia (family Agamidae) are known for their movement-based visual displays and are useful models for how ecology influences behaviour. However, we know little about the communication strategies of many species. Our aim here was to provide new knowledge on some of these species, focusing on the north-west of Western Australia. We filmed within-species pairwise interactions of Diporiphora superba, D. bennetti, D. sobria and Ctenophorus isolepis isolepis. We describe and quantify for the first time push-up displays by D. superba and C. isolepis isolepis and tail waving displays of D. bennetti. Only D. sobria did not generate movement-based visual signals. We have confirmed that more species engage in such behaviour than previously reported, but further work is required to document the full repertoire of these species. The implications of our work are discussed in the context of signal structure, function and environmental context.
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4
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Hui TY, Williams GA. Behavioural plasticity in the monsoonal tropics: implications for thermoregulatory traits in sandy shore crabs. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-03026-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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5
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Perez DM, Crisigiovanni EL, Pie MR, Rorato AC, Lopes SR, Araujo SBL. Ecology and signal structure drive the evolution of synchronous displays. Evolution 2019; 74:434-446. [PMID: 31503329 DOI: 10.1111/evo.13841] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 08/27/2019] [Accepted: 08/30/2019] [Indexed: 11/28/2022]
Abstract
Animal synchrony is found in phylogenetically distant animal groups, indicating behavioral adaptations to different selective pressures and in different signaling modalities. A notable example of synchronous display is found in fiddler crabs in that males wave their single enlarged claw during courtship. They present species-specific signals, which are composed of distinctive movement signatures. Given that synchronous waving has been reported for several fiddler crab species, the display pattern could influence the ability of a given species to sufficiently adjust wave timing to allow for synchrony. In this study, we quantified the wave displays of fiddler crabs to predict their synchronous behavior. We combined this information with the group's phylogenetic relationships to trace the evolution of display synchrony in an animal taxon. We found no phylogenetic signal in interspecific variation in predicted wave synchrony, which mirrors the general nonphylogenetic pattern of synchrony across animal taxa. Interestingly, our analyses show that the phenomenon of synchronization stems from the peculiarities of display pattern, mating systems, and the complexity of microhabitats. This is the first study to combine mathematical simulations and phylogenetic comparative methods to reveal how ecological factors and the mechanics of animal signals affect the evolution of the synchronous phenomena.
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Affiliation(s)
- Daniela M Perez
- Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - Enzo L Crisigiovanni
- Programa de Pós-Graduação em Ecologia e Conservação, Universidade Federal do Paraná, Curitiba, PR, 81531-990, Brazil.,Departamento de Física, Universidade Federal do Paraná, Curitiba, PR, 81531, Brazil
| | - Marcio R Pie
- Departamento de Zoologia, Departamento de Zoologia, Universidade Federal do Paraná, Curitiba, PR, 81531, Brazil
| | - Ana C Rorato
- Earth System Science Center, National Institute for Space Research (INPE), São José dos Campos, SP, 12227, Brazil
| | - Sergio R Lopes
- Departamento de Física, Universidade Federal do Paraná, Curitiba, PR, 81531, Brazil
| | - Sabrina B L Araujo
- Departamento de Física, Universidade Federal do Paraná, Curitiba, PR, 81531, Brazil.,Laboratório de Ecologia e Evolução de Interações, Biological Interactions, Universidade Federal do Paraná, Curitiba, PR, 81531, Brazil
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6
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Centorame M, Angelino D, Bonanni R, Fanfani A. Static and evolutionary allometry in the Italian endemic ant species Cataglyphis italica (Emery 1906). ETHOL ECOL EVOL 2019. [DOI: 10.1080/03949370.2019.1639080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Massimiliano Centorame
- Department of Biology and Biotecnology ‘Charles Darwin’, ‘Sapienza’ University of Rome, Viale dell’Università 32, Rome 00185, Italy
| | - Davide Angelino
- Department of Biology and Biotecnology ‘Charles Darwin’, ‘Sapienza’ University of Rome, Viale dell’Università 32, Rome 00185, Italy
| | - Roberto Bonanni
- Independent researcher, Via Giuseppe Donati 32, Rome 00159, Italy
| | - Alberto Fanfani
- Department of Biology and Biotecnology ‘Charles Darwin’, ‘Sapienza’ University of Rome, Viale dell’Università 32, Rome 00185, Italy
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Perez DM, Backwell PRY. Selection for conspicuous visual signals in a fiddler crab. Behav Ecol Sociobiol 2019. [DOI: 10.1007/s00265-019-2670-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Marshall NJ, Powell SB, Cronin TW, Caldwell RL, Johnsen S, Gruev V, Chiou THS, Roberts NW, How MJ. Polarisation signals: a new currency for communication. ACTA ACUST UNITED AC 2019; 222:222/3/jeb134213. [PMID: 30733259 DOI: 10.1242/jeb.134213] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Most polarisation vision studies reveal elegant examples of how animals, mainly the invertebrates, use polarised light cues for navigation, course-control or habitat selection. Within the past two decades it has been recognised that polarised light, reflected, blocked or transmitted by some animal and plant tissues, may also provide signals that are received or sent between or within species. Much as animals use colour and colour signalling in behaviour and survival, other species additionally make use of polarisation signalling, or indeed may rely on polarisation-based signals instead. It is possible that the degree (or percentage) of polarisation provides a more reliable currency of information than the angle or orientation of the polarised light electric vector (e-vector). Alternatively, signals with specific e-vector angles may be important for some behaviours. Mixed messages, making use of polarisation and colour signals, also exist. While our knowledge of the physics of polarised reflections and sensory systems has increased, the observational and behavioural biology side of the story needs more (and more careful) attention. This Review aims to critically examine recent ideas and findings, and suggests ways forward to reveal the use of light that we cannot see.
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Affiliation(s)
- N Justin Marshall
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Samuel B Powell
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Thomas W Cronin
- Department of Biological Sciences, University of Maryland Baltimore County, MD 21250, USA
| | - Roy L Caldwell
- University of California Berkeley, Department of Integrative Biology, Berkeley, CA 94720-3140, USA
| | - Sonke Johnsen
- Department of Biology, Duke University, Durham, NC 27708-0338, USA
| | - Viktor Gruev
- Electrical and Computer Engineering, University of Illinois, Urbana, IL 61801, USA
| | - T-H Short Chiou
- Department of Life Sciences, National Cheng-Kung University, Tainan City 701, Taiwan
| | - Nicholas W Roberts
- School of Biological Sciences, University of Bristol, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Martin J How
- School of Biological Sciences, University of Bristol, Tyndall Avenue, Bristol BS8 1TQ, UK
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Bywater CL, Wilson RS, Monro K, White CR. Legs of male fiddler crabs evolved to compensate for claw exaggeration and enhance claw functionality during waving displays. Evolution 2018; 72:2491-2502. [PMID: 30284733 DOI: 10.1111/evo.13617] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 09/21/2018] [Accepted: 09/28/2018] [Indexed: 11/28/2022]
Abstract
Many exaggerated morphological traits evolve under sexual selection. However, the optimal level of exaggeration is dictated by a trade-off between natural and sexual selection, representing a balance between its benefits and associated costs. Male fiddler crabs wave an enlarged major claw during behavioural displays that eliminates the need for direct combat, and determines courtship outcomes. The outcomes of these displays often depend on claw size, exposing males to selection for larger claws to improve mating and combat success. Applying phylogenetic comparative methods to 27 fiddler crab species, we examined the evolution of major claw morphologies, leg morphologies, and waving displays to determine whether these traits coevolved to optimise functioning of the exaggerated claw, or to mitigate potential metabolic or locomotor costs. We found legs to be sexually dimorphic, with males having longer legs than females. Legs were also longer in species that waved laterally rather than vertically, in species with larger major claws, and in species whose major claws were relatively elongate. These results suggest that leg morphology has coevolved with claw enlargement to enhance functionality of the major claw during waving displays, in addition to compensating for any negative effects of claw size.
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Affiliation(s)
- Candice L Bywater
- School of Biological Sciences, The University of Queensland, St Lucia, QLD 4072, Australia.,School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Robbie S Wilson
- School of Biological Sciences, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Keyne Monro
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia.,Centre for Geometric Biology, Monash University, Clayton, VIC 3800, Australia
| | - Craig R White
- School of Biological Sciences, The University of Queensland, St Lucia, QLD 4072, Australia.,School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia.,Centre for Geometric Biology, Monash University, Clayton, VIC 3800, Australia
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10
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Thurman CL, Hopkins MJ, Brase AL, Shih HT. The unusual case of the widely distributed fiddler crab Minuca rapax (Smith, 1870) from the western Atlantic: an exemplary polytypic species. INVERTEBR SYST 2018. [DOI: 10.1071/is18029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A classic dilemma in taxonomy is distinguishing intraspecific from interspecific variation. In order to better comprehend the process of divergence and speciation, we examine morphological, genetic, developmental and behavioural variation among related fiddler crab populations from eastern North America, the Caribbean and South America. We chose geographically remote populations that appear related to Minuca rapax (Smith, 1870). First, using females from across the range of the species, we use geometric morphometric techniques to identify regional differences in carapace shape. Second, in the northern portion of the range, the Caribbean into the Gulf of Mexico, we report variation in the relationship between corporal size and cheliped length in males. Third, we examine the major components of the courtship waves produced by males from several locations in the western Gulf of Mexico. Fourth, we compare the structure of the gastric mill between different populations in the Gulf of Mexico, the Caribbean and the Atlantic Ocean. And, fifth, we use mitochondrial 16S rDNA and cytochrome oxidase subunit I as genetic markers to define the phylogeographic relationship among specimens from more than 20 populations. From these studies, we find discrete, distinct populations across the original range of the species. In particular, populations in the northern Gulf of Mexico appear to represent a lineage that has resulted from limited gene flow and sustained selection pressures. On the basis of the observed degree of divergence, it is apparent that some separated populations in M. rapax should be recognised as evolutionary significant units. The geographic range of these populations is consistent with the historical range for Minuca virens (Salmon & Atsaides, 1968), a putative species that otherwise cannot be consistently distinguished from M. rapax based on discrete external morphological characters. This study provides evidence for M. virens as an emergent but possibly not completely isolated subclade of the M. rapax species complex.
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11
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Rorato AC, Araujo SB, Perez DM, Pie MR. Social cues affect synchronization of male waving displays in a fiddler crab (Crustacea: Ocypodidae). Anim Behav 2017. [DOI: 10.1016/j.anbehav.2017.02.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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12
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13
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Perez DM, Christy JH, Backwell PRY. Choosing a mate in a high predation environment: Female preference in the fiddler crab Uca terpsichores. Ecol Evol 2016; 6:7443-7450. [PMID: 28725411 PMCID: PMC5513263 DOI: 10.1002/ece3.2510] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 08/15/2016] [Accepted: 08/18/2016] [Indexed: 11/12/2022] Open
Abstract
The interplay between a receiver's sensory system and a sender's courtship signals is fundamental to the operation of sexual selection. Male courtship signals that match a female receiver's preexisting perceptual biases can be favored yet the message they communicate is not always clear. Do they simply beacon the male's location or also indicate his quality? We explored this question in a species of fiddler crab Uca terpsichores that courts under elevated predation risk and that mates and breeds underground in the safety of males' burrows. Sexually receptive females leave their own burrows and are thereby exposed to avian predators as they sequentially approach several courting males before they choose one. Males court by waving their single greatly enlarge claw and sometimes by building a sand hood next to their burrow entrance. Hoods are attractive because they elicit a risk-reducing orientation behavior in females, and it has been suggested that claw waving may also serve primarily to orient the female to the male. If the wave communicates male quality, then females should discriminate mates on the basis of variation in elements of the wave, as has been shown for other fiddler crabs. Alternatively, variation in elements of the claw waving display may have little effect on the display's utility as a beacon of the location of the male and his burrow. We filmed courting males and females under natural conditions as females responded to claw waving and chose mates. Analysis of the fine-scale courtship elements between the males that females rejected and those they chose revealed no differences. When predation risk during courtship is high, males' courtship displays may serve primarily to guide females to safe mating and breeding sites and not as indicators of male quality apart from their roles as beacons.
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Affiliation(s)
- Daniela M. Perez
- Research School of BiologyThe Australian National UniversityCanberraACTAustralia
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15
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16
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Kahn AT, Holman L, Backwell PR. Female preferences for timing in a fiddler crab with synchronous courtship waving displays. Anim Behav 2014. [DOI: 10.1016/j.anbehav.2014.09.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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17
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Holman L, Kahn AT, Backwell PRY. Fiddlers on the roof: elevation muddles mate choice in fiddler crabs. Behav Ecol 2014. [DOI: 10.1093/beheco/art125] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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How MJ, Zanker JM. Motion camouflage induced by zebra stripes. ZOOLOGY 2013; 117:163-70. [PMID: 24368147 DOI: 10.1016/j.zool.2013.10.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 09/15/2013] [Accepted: 10/07/2013] [Indexed: 10/25/2022]
Abstract
The functional significance of the zebra coat stripe pattern is one of the oldest questions in evolutionary biology, having troubled scientists ever since Charles Darwin and Alfred Russel Wallace first disagreed on the subject. While different theories have been put forward to address this question, the idea that the stripes act to confuse or 'dazzle' observers remains one of the most plausible. However, the specific mechanisms by which this may operate have not been investigated in detail. In this paper, we investigate how motion of the zebra's high contrast stripes creates visual effects that may act as a form of motion camouflage. We simulated a biologically motivated motion detection algorithm to analyse motion signals generated by different areas on a zebra's body during displacements of their retinal images. Our simulations demonstrate that the motion signals that these coat patterns generate could be a highly misleading source of information. We suggest that the observer's visual system is flooded with erroneous motion signals that correspond to two well-known visual illusions: (i) the wagon-wheel effect (perceived motion inversion due to spatiotemporal aliasing); and (ii) the barber-pole illusion (misperceived direction of motion due to the aperture effect), and predict that these two illusory effects act together to confuse biting insects approaching from the air, or possibly mammalian predators during the hunt, particularly when two or more zebras are observed moving together as a herd.
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Affiliation(s)
- Martin J How
- Queensland Brain Institute, University of Queensland, St Lucia, QLD 4000, Australia.
| | - Johannes M Zanker
- Department of Psychology, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
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Swanson BO, George MN, Anderson SP, Christy JH. Evolutionary variation in the mechanics of fiddler crab claws. BMC Evol Biol 2013; 13:137. [PMID: 23855770 PMCID: PMC3716949 DOI: 10.1186/1471-2148-13-137] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 06/04/2013] [Indexed: 11/10/2022] Open
Abstract
Background Fiddler crabs, genus Uca, are classic examples of how intense sexual selection can produce exaggerated male traits. Throughout the genus the enlarged “major” cheliped (claw) of the male fiddler crab is used both as a signal for attracting females and as a weapon for combat with other males. However, the morphology of the major claw is highly variable across the approximately 100 species within the genus. Here we address variation, scaling, and correlated evolution in the mechanics of the major claw by analyzing the morphology and mechanical properties of the claws of 21 species of fiddler crabs from the Pacific, Gulf and Atlantic coasts of the Americas. Results We find that the mechanics that produce claw closing forces, the sizes of claws and the mechanical strength of the cuticle of claws are all highly variable across the genus. Most variables scale isometrically with body size across species but claw force production scales allometrically with body size. Using phylogenetically independent contrasts, we find that the force that a claw can potentially produce is positively correlated with the strength of the cuticle on the claw where forces are delivered in a fight. There is also a negative correlation between the force that a claw can potentially produce and the size of the claw corrected for the mass of the claw. Conclusions These relationships suggest that there has been correlated evolution between force production and armoring, and that there is a tradeoff between claw mechanics for signaling and claw mechanics for fighting.
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Affiliation(s)
- Brook O Swanson
- Department of Biology, Gonzaga University, Spokane, WA 99258, USA.
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Araujo SBL, Rorato AC, Perez DM, Pie MR. A spatially explicit model of synchronization in fiddler crab waving displays. PLoS One 2013; 8:e57362. [PMID: 23483905 PMCID: PMC3590187 DOI: 10.1371/journal.pone.0057362] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 01/24/2013] [Indexed: 11/19/2022] Open
Abstract
Fiddler crabs (Uca spp., Decapoda: Ocypodidae) are commonly found forming large aggregations in intertidal zones, where they perform rhythmic waving displays with their greatly enlarged claws. While performing these displays, fiddler crabs often synchronize their behavior with neighboring males, forming the only known synchronized visual courtship displays involving reflected light and moving body parts. Despite being one of the most conspicuous aspects of fiddler crab behavior, little is known about the mechanisms underlying synchronization of male displays. In this study we develop a spatially explicit model of fiddler crab waving displays using coupled logistic map equations. We explored two alternative models in which males either direct their attention at random angles or preferentially toward neighbors. Our results indicate that synchronization is possible over a fairly large region of parameter space. Moreover, our model was capable of generating local synchronization neighborhoods, as commonly observed in fiddler crabs under natural conditions.
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Affiliation(s)
- Sabrina Borges Lino Araujo
- Programa de Pós-Graduação em Ecologia e Conservação, Universidade Federal do Paraná, Curitiba, Paraná, Brazil.
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PEREZ DANIELAM, ROSENBERG MICHAELS, PIE MARCIOR. The evolution of waving displays in fiddler crabs (Uca spp., Crustacea: Ocypodidae). Biol J Linn Soc Lond 2012. [DOI: 10.1111/j.1095-8312.2012.01860.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Darnell MZ, Munguia P. Thermoregulation as an Alternate Function of the Sexually Dimorphic Fiddler Crab Claw. Am Nat 2011; 178:419-28. [DOI: 10.1086/661239] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Rajkumar P, Rollmann SM, Cook TA, Layne JE. Molecular evidence for color discrimination in the Atlantic sand fiddler crab, Uca pugilator. ACTA ACUST UNITED AC 2011; 213:4240-8. [PMID: 21113005 DOI: 10.1242/jeb.051011] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Fiddler crabs are intertidal brachyuran crabs that belong to the genus Uca. Approximately 97 different species have been identified, and several of these live sympatrically. Many have species-specific body color patterns that may act as signals for intra- and interspecific communication. To understand the behavioral and ecological role of this coloration we must know whether fiddler crabs have the physiological capacity to perceive color cues. Using a molecular approach, we identified the opsin-encoding genes and determined their expression patterns across the eye of the sand fiddler crab, Uca pugilator. We identified three different opsin-encoding genes (UpRh1, UpRh2 and UpRh3). UpRh1 and UpRh2 are highly related and have similarities in their amino acid sequences to other arthropod long- and medium-wavelength-sensitive opsins, whereas UpRh3 is similar to other arthropod UV-sensitive opsins. All three opsins are expressed in each ommatidium, in an opsin-specific pattern. UpRh3 is present only in the R8 photoreceptor cell, whereas UpRh1 and UpRh2 are present in the R1-7 cells, with UpRh1 expression restricted to five cells and UpRh2 expression present in three cells. Thus, one photoreceptor in every ommatidium expresses both UpRh1 and UpRh2, providing another example of sensory receptor coexpression. These results show that U. pugilator has the basic molecular machinery for color perception, perhaps even trichromatic vision.
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Affiliation(s)
- Premraj Rajkumar
- Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio 45221, USA
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