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Lattanzio MS, McCann MJ, Manion M. Geographic Variation in the Ecomorphology and Thermal Ecology of a Widespread Lizard. HERPETOLOGICA 2020. [DOI: 10.1655/herpetologica-d-19-00032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Matthew S. Lattanzio
- Department of Organismal and Environmental Biology, Christopher Newport University, Newport News, VA 23606, USA
| | - Madison J. McCann
- Department of Organismal and Environmental Biology, Christopher Newport University, Newport News, VA 23606, USA
| | - Maleah Manion
- Department of Organismal and Environmental Biology, Christopher Newport University, Newport News, VA 23606, USA
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2
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Vrech D, Oviedo-Diego M, Olivero P, Peretti A. Successive matings produce opposite patterns on ejaculate volume and spermatozoa number in an ancient arthropod model with indirect sperm transfer. CAN J ZOOL 2019. [DOI: 10.1139/cjz-2018-0179] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The production of spermatophore and ejaculate is energetically expensive for males. High mating rates may accelerate sperm depletion and progressively decrease the size of the ejaculates. Sperm competition can shape spermatozoon numbers according to different signals and cues such as number of potential rivals or female mating status. Factors influencing patterns of sperm allocation have been neglected in terrestrial arthropods that transfer sperm indirectly using a complex sclerotized spermatophore deposited on the soil. We used the Neotropical scorpion Bothriurus bonariensis (C.L. Koch, 1842) to examine ejaculate volume, spermatozoon number, and spermatophore’s trunk length along three successive matings and their relationship with body size of males. Males mated and deposited a pre-insemination spermatophore every 10 days. Ejaculate volume and trunk length decreased, whereas spermatozoon number increased over matings. Male body size positively influenced ejaculate volume and trunk length interacted with mating event. High mating rates may decrease ejaculate volume. Sperm competition may produce increased spermatozoon number. Ejaculates are more energetically expensive than spermatozoa and larger males may better face the energetic requirements. Larger spermatophore trunks contain bigger ejaculate volume in the first two mating events, but this relationship disappears at the third mating event. Our discussion focuses on the factors responsible for the observed patterns.
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Affiliation(s)
- D.E. Vrech
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Diversidad Biológica y Ecología, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Laboratorio de Biología Reproductiva y Evolución, Córdoba, Argentina
- Catedra de Diversidad Biológica II
| | - M.A. Oviedo-Diego
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Diversidad Biológica y Ecología, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Laboratorio de Biología Reproductiva y Evolución, Córdoba, Argentina
| | - P.A. Olivero
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Diversidad Biológica y Ecología, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Laboratorio de Biología Reproductiva y Evolución, Córdoba, Argentina
| | - A.V. Peretti
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Diversidad Biológica y Ecología, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Laboratorio de Biología Reproductiva y Evolución, Córdoba, Argentina
- Catedra de Diversidad Biológica II
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3
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Abstract
One of the most pervasive ideas in the sexual selection literature is the belief that sexually selected traits almost universally exhibit positive static allometries (i.e., within a sample of conspecific adults, larger individuals have disproportionally larger traits). In this review, I show that this idea is contradicted by empirical evidence and theory. Although positive allometry is a typical attribute of some sexual traits in certain groups, the preponderance of positively allometric sexual traits in the empirical literature apparently results from a sampling bias reflecting a fascination with unusually exaggerated (bizarre) traits. I review empirical examples from a broad range of taxa illustrating the diversity of allometric patterns exhibited by signal, weapon, clasping and genital traits, as well as nonsexual traits. This evidence suggests that positive allometry may be the exception rather than the rule in sexual traits, that directional sexual selection does not necessarily lead to the evolution of positive allometry and, conversely, that positive allometry is not necessarily a consequence of sexual selection, and that many sexual traits exhibit sex differences in allometric intercept rather than slope. Such diversity in the allometries of secondary sexual traits is to be expected, given that optimal allometry should reflect resource allocation trade-offs, and patterns of sexual and viability selection on both trait size and body size. An unbiased empirical assessment of the relation between sexual selection and allometry is an essential step towards an understanding of this diversity.
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Affiliation(s)
- Russell Bonduriansky
- School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney NSW 2052, Australia.
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4
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Abstract
We tested the hypothesis that helodermatid lizards (Gila monsters, Heloderma suspectum Cope, 1869, and beaded lizards, H. horridum (Wiegmann, 1829)) show sexual dimorphism in morphological traits related to male–male agonistic behaviors. Male–male combat in helodermatid lizards involves repeated sequences of ritualized grappling. Male Gila monsters use their heads in attempts to gain or maintain a superior position during repeated combat bouts that may last for hours. Pairs of fighting male beaded lizards form spectacular body arches, with abdomens adpressed and snouts, forelimbs, and tail tips contacting the ground. We measured body size, head size, and tail length in 208 preserved H. suspectum, and body size and tail length (but not head size) in 79 live H. horridum, then tested for sexual dimorphism using analysis of covariance. Male Gila monsters had proportionately larger heads than females but did not differ in tail length or body size. Male beaded lizards had proportionately longer tails than females and were larger in body size only when the largest individuals were included in the analysis. Differences in head dimensions (in H. suspectum) and tail length (in H. horridum) are likely the result of sexual selection acting through male–male agonistic behaviors in this unique lizard taxon.
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Affiliation(s)
- C.M. Gienger
- Program in Ecology, Evolution, and Conservation Biology, University of Nevada, Reno, NV 89557, USA
- Department of Biological Sciences, Central Washington University, Ellensburg, WA 98926, USA
| | - Daniel D. Beck
- Program in Ecology, Evolution, and Conservation Biology, University of Nevada, Reno, NV 89557, USA
- Department of Biological Sciences, Central Washington University, Ellensburg, WA 98926, USA
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5
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Bussiégre LF, Hunt J, Jennions MD, Brooks R. SEXUAL CONFLICT AND CRYPTIC FEMALE CHOICE IN THE BLACK FIELD CRICKET, TELEOGRYLLUS COMMODUS. Evolution 2006. [DOI: 10.1111/j.0014-3820.2006.tb01157.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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6
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Bonduriansky R, Rowe L. INTRALOCUS SEXUAL CONFLICT AND THE GENETIC ARCHITECTURE OF SEXUALLY DIMORPHIC TRAITS IN PROCHYLIZA XANTHOSTOMA (DIPTERA: PIOPHILIDAE). Evolution 2005. [DOI: 10.1111/j.0014-3820.2005.tb01066.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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7
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Wong BBM, Candolin U. How is female mate choice affected by male competition? Biol Rev Camb Philos Soc 2005; 80:559-71. [PMID: 16221329 DOI: 10.1017/s1464793105006809] [Citation(s) in RCA: 305] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2004] [Revised: 03/21/2005] [Accepted: 03/23/2005] [Indexed: 11/06/2022]
Abstract
The plethora of studies devoted to the topics of male competition and female mate choice belie the fact that their interaction remains poorly understood. Indeed, on the question of whether competition should help or hinder the choice process, opinions scattered throughout the sexual selection literature seem unnecessarily polarised. We argue, in the light of recent theoretical and empirical advances, that the effect of competition on mate choice depends on whether it results in the choosy sex attaining high breeding value for total fitness, considering both direct and indirect fitness benefits. Specifically, trade-offs may occur between different fitness benefits if some are correlated with male competitive ability whilst others are not. Moreover, the costs and benefits of mating with competitive males may vary in time and/or space. These considerations highlight the importance of injecting a life-history perspective into sexual selection studies. Within this context, we turn to the sexual selection literature to try to offer insights into the circumstances when competition might be expected to have positive or negative implications for pre-copulatory female choice. In this regard, we elaborate on three stages where competition might impact upon the choice process: (i) during mate detection, (ii) mate evaluation, and (iii) in dictating actual mating outcomes. We conclude by offering researchers several potentially rewarding avenues for future research.
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Affiliation(s)
- Bob B M Wong
- School of Botany and Zoology, Australian National University, Canberra, ACT 0200, Australia.
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8
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Bonduriansky R, Rowe L. SEXUAL SELECTION, GENETIC ARCHITECTURE, AND THE CONDITION DEPENDENCE OF BODY SHAPE IN THE SEXUALLY DIMORPHIC FLY PROCHYLIZA XANTHOSTOMA (PIOPHILIDAE). Evolution 2005. [DOI: 10.1111/j.0014-3820.2005.tb00901.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Candolin U. OPPOSING SELECTION ON A SEXUALLY DIMORPHIC TRAIT THROUGH FEMALE CHOICE AND MALE COMPETITION IN A WATER BOATMAN. Evolution 2004; 58:1861-4. [PMID: 15446439 DOI: 10.1111/j.0014-3820.2004.tb00470.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Female choice and male-male competition are traditionally considered to act in concert, with male competition facilitating female choice. This situation would enforce the strength of directional selection, which could reduce genetic variation and thus the benefits of choice. Here I show that in a water boatman, Sigara falleni, the direction of selection through female choice and male competition vary among traits under laboratory conditions. The two forces were mutually enforcive in acting on body size but exerted opposing selection on a sexually selected trait, male foreleg pala size. Female choice favored large palae, whereas male competition favored smaller palae, suggesting that large palae are costly in competition. This conflicting selection through female choice and male competition could be one of the forces that contribute to the maintenance of genetic variation in sexually selected traits.
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Affiliation(s)
- Ulrika Candolin
- Department of Biological & Environmental Sciences, University of Helsinki, FIN-00014 Helsinki, Finland.
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