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Louâpre P, Muller K, Bettencourt-Amarante S, Thiery D, Moreau J. Sexual audience affects male's reproduction investment without consequences on reproductive outputs. INSECT SCIENCE 2022; 29:1170-1180. [PMID: 34897988 DOI: 10.1111/1744-7917.12990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 10/15/2021] [Accepted: 11/17/2021] [Indexed: 06/14/2023]
Abstract
Males evolved plastic strategies to respond to male-male competition and exhibit adaptive traits and behaviors maximizing their access to the females and limiting sperm competition. Mating behaviors allow males to express quick responses to current sexual audience, that is, the number of nearby conspecifics prone to mate. In contrast, physiological responses are frequently delayed because they are constrained by the time and resources having to be mobilized to produce and export sperm and associated products. This is especially critical in species for which males produce spermatophores. Here we investigated in what extend moth males (the tortricid moth Lobesia botrana) producing spermatophores exhibit plastic behavioral and physiological responses to different sexual audiences before and during mating and the consequences for their reproductive output. We found that males adjusted their mating behaviors and spermatophore size to a potentially elevated risk of sperm competition perceived before mating. In addition, males responded to the closed presence of females during mating by reducing their mating duration. Surprisingly, the various behavioral and physiological responses we highlighted here were not fully reflected in their reproductive performance as we did not reveal any effect on fecundity and fertility of their mate. The selective pressure exerted on males experiencing male-male competition could thus be sufficient to trigger adjustment in male mating behaviors but constrains physiological responses according to the perception of competition.
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Affiliation(s)
- Philippe Louâpre
- UMR CNRS 6282 Biogeosciences, Université Bourgogne Franche-Comté, Dijon, France
| | - Karen Muller
- UMR CNRS 6282 Biogeosciences, Université Bourgogne Franche-Comté, Dijon, France
| | | | - Denis Thiery
- INRA UMR 1065 Santé et Agroecologie du Vignoble, Institut des Science de la Vigne et du Vin, Villenave d'Ornon, Cedex, France
- INRA UMR 1065, Save, Université de Bordeaux, Bordeaux Sciences Agro, Villenave d'Ornon, Cedex, France
| | - Jérôme Moreau
- UMR CNRS 6282 Biogeosciences, Université Bourgogne Franche-Comté, Dijon, France
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2
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Sperm oxidative status varies with the level of sperm competition and affects male reproductive success. Anim Behav 2022. [DOI: 10.1016/j.anbehav.2022.04.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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3
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Strategic adjustment of ejaculate quality in response to variation of the socio-sexual environment. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-03032-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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4
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Maggu K, Ahlawat N, Geeta Arun M, Meena A, Prasad NG. Divergence of responses to variable socio-sexual environments in laboratory populations of Drosophila melanogaster evolving under altered operational sex ratios. Evolution 2020; 75:414-426. [PMID: 33319380 DOI: 10.1111/evo.14138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 11/07/2020] [Accepted: 11/13/2020] [Indexed: 11/27/2022]
Abstract
Post-copulatory sexual selection (PSS) is an important selective force that determines fitness in polyandrous species. PSS can be intense in some cases and can drive the evolution of remarkable ejaculate properties. In males, investment in ejaculate plays an important role in the outcome of PSS. Thus, males are expected to adaptively tailor their ejaculate according to the perceived competition in their vicinity. Plastic responses in ejaculate investment to variation in intrasexual competition are disparate and widespread in males. We investigated the evolution of plasticity in reproductive traits using Drosophila melanogaster populations evolving for more than 150 generations under male- or female-biased sex ratios. When exposed to different numbers of competitors early in their life, males from these two regimes responded differently in terms of their copulation duration and sperm competitive ability. In addition, the effect of this early life experience wore off at different rates in males of male-biased and female-biased regimes with increasing time from the removal of competitive cues. Furthermore, our study finds that males change their reproductive strategies depending upon the identity of rival males. Together, our results provide evidence of the evolution of male reproductive investment that depends on socio-sexual cues experienced early in life.
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Affiliation(s)
- Komal Maggu
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, India
| | - Neetika Ahlawat
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, India
| | - Manas Geeta Arun
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, India
| | - Abhishek Meena
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, India
| | - Nagaraj Guru Prasad
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, India
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5
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Parker GA. Conceptual developments in sperm competition: a very brief synopsis. Philos Trans R Soc Lond B Biol Sci 2020; 375:20200061. [PMID: 33070727 DOI: 10.1098/rstb.2020.0061] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The past half century has seen the development of the field of post-ejaculatory sexual selection, the sequel to sexual selection for mate-acquisition (pre-ejaculatory) described by Darwin. In richness and diversity of adaptations, post-ejaculatory selection rivals that of pre-ejaculatory sexual selection. Anisogamy-and hence two sexes-likely arose by primeval gamete competition, and sperm competition remains a major force maintaining high sperm numbers. The post-ejaculatory equivalent of male-male competition for matings, sperm competition was an intense ancestral form of sexual selection, typically weakening as mobility and internal fertilization developed in many taxa, when some expenditure became diverted into pre-ejaculatory competition. Sperm competition theory has been relatively successful in explaining variation in relative testes size and sperm numbers per ejaculate and is becoming more successful in explaining variation in sperm phenotype. Sperm competition has generated many other male adaptations such as seminal fluid proteins that variously modify female reproduction towards male interests, and copulatory plugs, prolonged copulations and post-ejaculatory guarding behaviour that reduce female remating probability, many of which result in sexual conflict. This short survey of conceptual developments is intended as a broad overview, mainly as a primer for new researchers. This article is part of the theme issue 'Fifty years of sperm competition'.
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Affiliation(s)
- Geoff A Parker
- Department of Evolution, Ecology and Behaviour, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK
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6
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Esfandi K, He XZ, Wang Q. Sperm allocation strategies in a sperm heteromorphic insect. Curr Zool 2020; 66:285-292. [PMID: 32440289 PMCID: PMC7234108 DOI: 10.1093/cz/zoz048] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 09/29/2019] [Indexed: 01/25/2023] Open
Abstract
Theories predict that in polyandrous species, the focal male should increase sperm allocation per mate in the presence of rivals to gain greater share of paternity, but in the presence of additional mates, he should reduce sperm allocation per mate to save sperm for insemination of more mates. However, empirical findings are often inconsistent and reasons behind are unclear. Furthermore, many studies use copulation duration as an estimate of the number of sperm transferred. Yet, empirical evidence for such assumption is largely lacking. Here, we used a sperm heteromorphic insect Ephestia kuehniella whose males produce two types of sperm, eupyrenes (fertile) and apyrenes (nonfertile), to test these postulations. We allowed focal males to detect chemical and acoustic but no tactile cues from rivals or additional mates both before and during mating and measured copulation duration and sperm allocation in successive copulations. We demonstrate that males transfer significantly more eupyrenes per mate in the presence of rivals and that the sperm allocation pattern persists in successive copulations under this condition. However, males do not adjust apyrene allocation in response to rivals probably because apyrenes play a relatively minor role in male reproductive success. Contrary to a previous study, focal males do not respond to additional mates most likely due to the lack of tactile cues in the present study. We reveal that sperm allocation is not a function of copulation duration in this insect for spermatophore formation and delivery occupy most of copulation duration and sperm transfer is complete near the end of copulation.
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Affiliation(s)
- Kambiz Esfandi
- School of Agriculture and Environment, Massey University, Private Bag 11222, Palmerston North, New Zealand.,The New Zealand Institute for Plant & Food Research Limited, Private Bag 11600, Palmerston North, New Zealand
| | - Xiong Z He
- School of Agriculture and Environment, Massey University, Private Bag 11222, Palmerston North, New Zealand
| | - Qiao Wang
- School of Agriculture and Environment, Massey University, Private Bag 11222, Palmerston North, New Zealand
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7
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Lymbery SJ, Simmons LW. Gustatory cues to kinship among males moderate the productivity of females. Behav Ecol 2019. [DOI: 10.1093/beheco/arz158] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AbstractMales of many species harm females as a byproduct of intrasexual competition, but this harm can be reduced if males are less competitive in the presence of familiar relatives. We determined the cue males use to identify competitors in this context. We assessed genetic variance in a putative kin recognition trait (cuticular hydrocarbons) in male seed beetles Callosobruchus maculatus and found that five hydrocarbons had significant components of additive genetic variance and could serve as relatedness cues. Next, we tested whether hydrocarbons were the mechanism males use to distinguish the social identities of competitors when strategically adjusting their competitiveness/harmfulness. Pairs of female and male C. maculatus were mated in the presence of hydrocarbons extracted from males that differed in their relatedness and familiarity to the focal male. Females were more productive after mating in the presence of extracts from the focal male’s nonrelatives, if those extracts were also unfamiliar to the focal male. Relatedness had no effect on productivity when extracts were familiar to the focal male. These results may be reconciled with those of previous studies that manipulated the relatedness and familiarity of competing males if the difference between the effect of harmfulness on productivity following a single mating and the effect on lifetime reproductive fitness after multiple matings is accounted for. This study provides a novel demonstration of the mechanism of social recognition in the moderation of sexual conflict.
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Affiliation(s)
- Samuel J Lymbery
- Centre for Evolutionary Biology, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Leigh W Simmons
- Centre for Evolutionary Biology, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
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8
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Macartney EL, Crean AJ, Nakagawa S, Bonduriansky R. Effects of nutrient limitation on sperm and seminal fluid: a systematic review and meta-analysis. Biol Rev Camb Philos Soc 2019; 94:1722-1739. [PMID: 31215758 DOI: 10.1111/brv.12524] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Revised: 05/01/2019] [Accepted: 05/03/2019] [Indexed: 01/05/2023]
Abstract
Theory predicts that costly sexual traits should be reduced when individuals are in poor condition (i.e. traits should exhibit condition-dependent expression). It is therefore widely expected that male ejaculate traits, such as sperm and seminal fluid, will exhibit reduced quantity and quality when dietary nutrients are limited. However, reported patterns of ejaculate condition dependence are highly variable, and there has been no comprehensive synthesis of underlying sources of such variation in condition-dependent responses. In particular, it remains unclear whether all ejaculate traits are equally sensitive to nutrient intake, and whether such traits are particularly sensitive to certain dietary nutrients, respond more strongly to nutrients during specific life stages, or respond more strongly in some taxonomic groups. We systematically reviewed these potential sources of variation through a meta-analysis across 50 species of arthropods and vertebrates (from 71 papers and 348 effect sizes). We found that overall, ejaculate traits are moderately reduced when dietary nutrients are limited, but we also detected substantial variation in responses. Seminal fluid quantity was strongly and consistently condition dependent, while sperm quantity was moderately condition dependent. By contrast, aspects of sperm quality (particularly sperm viability and morphology) were less consistently reduced under nutrient limitation. Ejaculate traits tended to respond in a condition-dependent manner to a wide range of dietary manipulations, especially to caloric and protein restriction. Finally, while all major taxa for which sufficient data exist (i.e. arthropods, mammals, fish) showed condition dependence of ejaculate traits, we detected some taxonomic differences in the life stage that is most sensitive to nutrient limitation, and in the degree of condition dependence of specific ejaculate traits. Together, these biologically relevant factors accounted for nearly 20% of the total variance in ejaculate responses to nutrient limitation. Interestingly, body size showed considerably stronger condition-dependent responses compared to ejaculate traits, suggesting that ejaculate trait expression may be strongly canalised to protect important reproductive functions, or that the cost of producing an ejaculate is relatively low. Taken together, our findings show that condition-dependence of ejaculate traits is taxonomically widespread, but there are also many interesting, biologically relevant sources of variation that require further investigation. In particular, further research is needed to understand the differences in selective pressures that result in differential patterns of ejaculate condition dependence across taxa and ejaculate traits.
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Affiliation(s)
- Erin L Macartney
- Evolution and Ecology Research Centre and School of Biological, Earth and Environmental Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Angela J Crean
- Sydney School of Veterinary Science, The University of Sydney, Sydney, New South Wales, Australia
| | - Shinichi Nakagawa
- Evolution and Ecology Research Centre and School of Biological, Earth and Environmental Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Russell Bonduriansky
- Evolution and Ecology Research Centre and School of Biological, Earth and Environmental Sciences, UNSW Australia, Sydney, New South Wales, Australia
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9
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Lymbery SJ, Tomkins JL, Simmons LW. Male responses to sperm competition when rivals vary in number and familiarity. Proc Biol Sci 2019; 286:20182589. [PMID: 30963943 PMCID: PMC6364580 DOI: 10.1098/rspb.2018.2589] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 01/09/2019] [Indexed: 12/20/2022] Open
Abstract
Males of many species adjust their reproductive investment to the number of rivals present simultaneously. However, few studies have investigated whether males sum previous encounters with rivals, and the total level of competition has never been explicitly separated from social familiarity. Social familiarity can be an important component of kin recognition and has been suggested as a cue that males use to avoid harming females when competing with relatives. Previous work has succeeded in independently manipulating social familiarity and relatedness among rivals, but experimental manipulations of familiarity are confounded with manipulations of the total number of rivals that males encounter. Using the seed beetle Callosobruchus maculatus, we manipulated three factors: familiarity among rival males, the maximum number of rivals encountered simultaneously and the total number of rivals encountered over a 48 h period. Males produced smaller ejaculates when exposed to more rivals in total, regardless of the maximum number of rivals they encountered simultaneously. Males did not respond to familiarity. Our results demonstrate that males of this species can sum the number of rivals encountered over separate days, and therefore the confounding of familiarity with the total level of competition in previous studies should not be ignored.
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Affiliation(s)
- Samuel J. Lymbery
- Centre for Evolutionary Biology, School of Animal Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
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10
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Garefalaki ME, Kalyva S, Janicke T, Staikou A. Intraspecific variation in reproductive characters is associated with the strength of sexual selection in the hermaphroditic land snail Cornu aspersum. Behav Ecol Sociobiol 2017. [DOI: 10.1007/s00265-017-2383-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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11
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Mohorianu I, Bretman A, Smith DT, Fowler EK, Dalmay T, Chapman T. Genomic responses to the socio-sexual environment in male Drosophila melanogaster exposed to conspecific rivals. RNA (NEW YORK, N.Y.) 2017; 23:1048-1059. [PMID: 28428330 PMCID: PMC5473139 DOI: 10.1261/rna.059246.116] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 04/10/2017] [Indexed: 06/07/2023]
Abstract
Socio-sexual environments have profound effects on fitness. Local sex ratios can alter the threat of sexual competition, to which males respond via plasticity in reproductive behaviors and ejaculate composition. In Drosophila melanogaster, males detect the presence of conspecific, same-sex mating rivals prior to mating using multiple, redundant sensory cues. Males that respond to rivals gain significant fitness benefits by altering mating duration and ejaculate composition. Here we investigated the underlying genome-wide changes involved. We used RNA-seq to analyze male transcriptomic responses 2, 26, and 50 h after exposure to rivals, a time period that was previously identified as encompassing the major facets of male responses to rivals. The results showed a strong early activation of multiple sensory genes in the head-thorax (HT), prior to the expression of any phenotypic differences. This gene expression response was reduced by 26 h, at the time of maximum phenotypic change, and shut off by 50 h. In the abdomen (A), fewer genes changed in expression and gene expression responses appeared to increase over time. The results also suggested that different sets of functionally equivalent genes might be activated in different replicates. This could represent a mechanism by which robustness is conferred upon highly plastic traits. Overall, our study reveals that mRNA-seq can identify subtle genomic signatures characteristic of flexible behavioral phenotypes.
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Affiliation(s)
- Irina Mohorianu
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
| | - Amanda Bretman
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
- School of Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Damian T Smith
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
| | - Emily K Fowler
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
| | - Tamas Dalmay
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
| | - Tracey Chapman
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
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12
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Rebar D, Greenfield MD. When do acoustic cues matter? Perceived competition and reproductive plasticity over lifespan in a bushcricket. Anim Behav 2017. [DOI: 10.1016/j.anbehav.2017.03.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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13
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Tuni C, Weber S, Bilde T, Uhl G. Male spiders reduce pre- and postmating sexual investment in response to sperm competition risk. Behav Ecol 2017. [DOI: 10.1093/beheco/arx061] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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14
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Haneke-Reinders M, Reinhold K, Schmoll T. Sex-specific repeatabilities and effects of relatedness and mating status on copulation duration in an acridid grasshopper. Ecol Evol 2017; 7:3414-3424. [PMID: 28515877 PMCID: PMC5433977 DOI: 10.1002/ece3.2937] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 01/27/2017] [Accepted: 03/03/2017] [Indexed: 11/16/2022] Open
Abstract
In species with direct sperm transfer, copulation duration is a crucial trait that may affect male and female reproductive success and that may vary with the quality of the mating partner. Furthermore, traits such as copulation duration represent the outcome of behavioral interactions between the sexes, for which it is important—but often difficult—to determine which sex is in phenotypic control. Using a double‐mating protocol, we compared copulation durations between (1) virgin and nonvirgin and (2) sibling and nonsibling mating pairs in rufous grasshoppers Gomphocerippus rufus. Nonvirgin copulations took on average approximately 30% longer than virgin copulations, whereas relatedness of mating partners was not a significant predictor of copulation duration. Longer nonvirgin copulations may represent a male adaptation to sperm competition if longer copulations allow more sperm to be transferred or function as postinsemination mate guarding. The absence of differences between pairs with different degrees of relatedness suggests no precopulatory or preinsemination inbreeding avoidance mechanism has evolved in this species, perhaps because there is no inbreeding depression in this species, or because inbreeding avoidance occurs after copulation. Controlling for the effects of male and female mating status (virgin vs. nonvirgin) and relatedness (sibling vs. nonsibling), we found significant repeatabilities (R) in copulation duration for males (R = 0.33; 95% CI: 0.09–0.55) but not for females (R = 0.09; 95% CI: 0.00–0.30). Thus, copulation durations of males more strongly represent a nontransient trait expressed in a consistent manner with different mating partners, suggesting that some aspect of the male phenotype may determine copulation duration in this species. However, overlapping confidence intervals for our sex‐specific repeatability estimates indicate that higher sampling effort is required for conclusive evidence.
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Affiliation(s)
| | - Klaus Reinhold
- Evolutionary Biology Bielefeld University North Rhine-Westphalia Germany
| | - Tim Schmoll
- Evolutionary Biology Bielefeld University North Rhine-Westphalia Germany
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15
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Chechi TS, Ali Syed Z, Prasad NG. Virility does not imply immensity: Testis size, accessory gland size and ejaculate depletion pattern do not evolve in response to experimental manipulation of sex ratio in Drosophila melanogaster. JOURNAL OF INSECT PHYSIOLOGY 2017; 98:67-73. [PMID: 27913151 DOI: 10.1016/j.jinsphys.2016.11.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 11/21/2016] [Accepted: 11/22/2016] [Indexed: 06/06/2023]
Abstract
Sperm competition theory predicts that with increase in sperm competition, males either invest more in reproductive organ(s) and/or improve ejaculate investment. We test this idea using experimental evolution in Drosophila melanogaster. We maintained replicate populations of Drosophila melanogaster under male (M) and female (F) biased sex ratio regimes for more than a hundred generations with the result that males from the M regime evolved higher sperm competitive abilities relative to males from the F regime. In the present study, we measured the testes and the accessory gland size of virgin and singly mated males from the M and F regimes. The M and F males do not differ in either testis or accessory gland size. Additionally, ejaculate investment is not different in the M and F males, as measured by reduction in testis and accessory gland sizes. Thus, contrary to theoretical prediction and evidence from other species, we found that evolved differences in sperm competitive ability are not necessarily due to evolution of testis/accessory gland size or strategic ejaculate investment in these populations.
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Affiliation(s)
- Tejinder Singh Chechi
- Indian Institute of Science Education and Research, Mohali, Knowledge City, Sector 81, SAS Nagar, Mohali, Punjab 140306, India
| | - Zeeshan Ali Syed
- Indian Institute of Science Education and Research, Mohali, Knowledge City, Sector 81, SAS Nagar, Mohali, Punjab 140306, India
| | - Nagaraj Guru Prasad
- Indian Institute of Science Education and Research, Mohali, Knowledge City, Sector 81, SAS Nagar, Mohali, Punjab 140306, India.
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16
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Schütz D, Tschirren L, Pachler G, Grubbauer P, Taborsky M. Sperm-limited males save ejaculates for future matings when competing with superior rivals. Anim Behav 2017. [DOI: 10.1016/j.anbehav.2016.12.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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17
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Kelly CD, Gwynne DT. The effect of condition on mate searching speed and copulation frequency in the Cook Strait giant weta. Behav Ecol Sociobiol 2016. [DOI: 10.1007/s00265-016-2150-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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18
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Affiliation(s)
- G. A. Parker
- Institute of Integrative Biology; University of Liverpool; Liverpool UK
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19
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20
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Esfandi K, He XZ, Wang Q. Flirtation reduces males' fecundity but not longevity. Evolution 2015; 69:2118-28. [PMID: 26133013 DOI: 10.1111/evo.12715] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 06/19/2015] [Indexed: 11/27/2022]
Abstract
Theory predicts that due to limited resources males should strategically adjust their investment in reproduction and survival. Based on different conceptual framework, experimental designs, and study species, many studies support while others contradict this general prediction. Using a moth Ephestia kuehniella whose adults do not feed and thus have fixed resources for their lifetime fitness, we investigated whether males adjusted their investment in various life activities under dynamic socio-sexual environment. We allowed focal males to perceive rivals or additional females without physical contact. We show that males do not adjust the number of sperm they transfer to mates in a given copulation at different immediate or both immediate and mean sperm competition levels. Contradictory to general predictions, our results demonstrate that cues from additional females increase males' investment in courtship and reduce their lifetime number of copulations and sperm ejaculated, whereas cues from rivals have no effect on these parameters. Males have similar longevity in all treatments. We suggest that the sex pheromone produced by multiple females overstimulate males, increasing males' costly flirtations, and reducing their lifetime copulation frequency and fecundity. This finding offers a novel explanation for the success of mating disruption strategy using sex pheromones in pest management.
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Affiliation(s)
- Kambiz Esfandi
- Institute of Agriculture and Environment, Massey University, Palmerston North, Private Bag 11222, New Zealand
| | - Xiong Zhao He
- Institute of Agriculture and Environment, Massey University, Palmerston North, Private Bag 11222, New Zealand
| | - Qiao Wang
- Institute of Agriculture and Environment, Massey University, Palmerston North, Private Bag 11222, New Zealand.
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21
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Janssen R, Baur B. Seasonal effects on egg production and level of paternity in a natural population of a simultaneous hermaphrodite snail. Ecol Evol 2015; 5:2916-28. [PMID: 26306176 PMCID: PMC4541995 DOI: 10.1002/ece3.1560] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Revised: 05/10/2015] [Accepted: 05/19/2015] [Indexed: 11/22/2022] Open
Abstract
In a seasonal environment, the suitable time window for females to reproduce is restricted by both environmental conditions and the availability of males. In simultaneous hermaphrodites, which are female and male at the same time, selection on a trait that is solely beneficial for one sexual function cannot occur independently. Therefore, it is assumed that the optimal time window for reproduction is a compromise between the two sexual functions in simultaneous hermaphrodites, mediated by environmental conditions. We examined seasonal patterns of reproduction and the resulting paternity in a natural population of the simultaneously hermaphroditic land snail Arianta arbustorum. Adult and premature individuals (snails in a short protandric phase) were collected on four occasions over the entire active season. The snails were allowed to deposit eggs after which we assessed the level of paternity in their hatched offspring. Individuals mated throughout the reproductive season, whereas egg production - the major task of the female function - was restricted to the first half of the season. Snails collected in autumn were allowed to hibernate under laboratory conditions. As a result, we found that premature individuals began to mate late in the reproductive season, but did not start to produce eggs before emerging from hibernation. Our results demonstrate a temporal shift of reproductive activities; the egg production and oviposition occur mainly in the first half of the season, while sperm production and mating occur over the entire season. In subadult and adult snails, sperm obtained from several partners in the second part of the reproductive season are stored during hibernation for the fertilization of eggs in the successive years. These results extend our understanding of the influence of both natural and sexual selection on reproductive strategies in hermaphrodites.
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Affiliation(s)
- Ruben Janssen
- Section of Conservation Biology, Department of Environmental Sciences, University of BaselSt. Johanns-Vorstadt 10, CH-4056, Basel, Switzerland
| | - Bruno Baur
- Section of Conservation Biology, Department of Environmental Sciences, University of BaselSt. Johanns-Vorstadt 10, CH-4056, Basel, Switzerland
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Abraham S, Vera MT, Pérez-Staples D. Current Sperm Competition Determines Sperm Allocation in a Tephritid Fruit Fly. Ethology 2015. [DOI: 10.1111/eth.12355] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Solana Abraham
- Laboratorio de Investigaciones Ecoetológicas de Moscas de la Fruta y sus Enemigos Naturales (LIEMEN); PROIMI; Tucumán Argentina
- CONICET; Buenos Aires Argentina
| | - M. Teresa Vera
- CONICET; Buenos Aires Argentina
- Cátedra de Terapéutica Vegetal; Departamento de Sanidad Vegetal de la Facultad de Agronomía y Zootecnia de la UNT; Tucumán Argentina
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Myers SS, Buckley TR, Holwell GI. Mate detection and seasonal variation in stick insect mating behaviour (Phamatodea: Clitarchus hookeri). BEHAVIOUR 2015. [DOI: 10.1163/1568539x-00003281] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
For animals that exhibit a scramble competition mating system, sexual selection pressures on mate searching ability are expected to be strong. Scramble competition mating systems evolve when populations provide females with equal accessibility to all male competitors, yet sex ratio and population density influences mating systems and varies seasonally. The stick insect species,Clitarchus hookeri, is frequently found in copula, yet very little is known about it’s mating behaviour. We preformed behavioural tests and assayed antennal sensory morphology to determine whether males used chemosensory cues to detect females. Through natural field observations we found populations to be significantly male-biased earlier in the season, while later, populations began to display equal sex ratios. With increasing female availability mating pair proportions steadily increased, while copulation duration declined. These results supportC. hookerias a scramble competitor, and demonstrate males may alter their behaviour in response to the seasonal variation in female density.
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Affiliation(s)
- Shelley S. Myers
- Landcare Research, Private Bag 92170, Auckland 1142, New Zealand
- The School of Biological Sciences, The University of Auckland, 1142, New Zealand
- Allan Wilson Centre, Auckland, New Zealand
| | - Thomas R. Buckley
- Landcare Research, Private Bag 92170, Auckland 1142, New Zealand
- The School of Biological Sciences, The University of Auckland, 1142, New Zealand
- Allan Wilson Centre, Auckland, New Zealand
| | - Gregory I. Holwell
- The School of Biological Sciences, The University of Auckland, 1142, New Zealand
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24
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Requena GS, Alonzo SH. Female sperm use and storage between fertilization events drive sperm competition and male ejaculate allocation. Evolution 2014; 68:3433-44. [PMID: 25307988 DOI: 10.1111/evo.12540] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 09/09/2014] [Indexed: 11/28/2022]
Abstract
Sperm competition theory has traditionally focused on how male allocation responds to female promiscuity, when males compete to fertilize a single clutch of eggs. Here, we develop a model to ask how female sperm use and storage across consecutive reproductive events affect male ejaculate allocation and patterns of mating and paternity. In our model, sperm use (a single parameter under female control) is the main determinant of sperm competition, which alters the effect of female promiscuity on male success and, ultimately, male reproductive allocation. Our theory reproduces the general pattern predicted by existing theory that increased sperm competition favors increased allocation to ejaculates. However, our model predicts a negative correlation between male ejaculate allocation and female promiscuity, challenging the generality of a prevailing expectation of sperm competition theory. Early models assumed that the energetic costs of precopulatory competition and the level of sperm competition are both determined by female promiscuity, which leads to an assumed covariation between these two processes. By modeling precopulatory costs and sperm competition independently, our theoretical framework allows us to examine how male allocation should respond independently to variation in sperm competition and energetic trade-offs in mating systems that have been overlooked in the past.
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Affiliation(s)
- Gustavo S Requena
- Department of Ecology and Evolutionary Biology, Yale University, 165 Prospect Street, New Haven, Connecticut 06520.
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25
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Moatt JP, Dytham C, Thom MDF. Sperm production responds to perceived sperm competition risk in male Drosophila melanogaster. Physiol Behav 2014; 131:111-4. [PMID: 24769021 DOI: 10.1016/j.physbeh.2014.04.027] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 04/07/2014] [Accepted: 04/14/2014] [Indexed: 11/19/2022]
Abstract
Postcopulatory sexual selection arising from female multiple mating leads to the evolution of ejaculates that maximize a male's reproductive success under sperm competition. Where the risk of sperm competition is variable, optimal fitness may be achieved by plastically altering ejaculate characteristics in response to the prevailing sperm competition environment. In the model species Drosophila melanogaster, males expecting to encounter sperm competition mate for longer and transfer more accessory proteins and sperm. Here we show that after being housed with a single rival for one week, the seminal vesicles of male D. melanogaster contain a significantly greater proportion of live sperm than those of males maintained alone, indicating adaptive adjustment of sperm quality in response to the perceived risk of sperm competition. This effect is due to an increase in the number of live sperm produced, indicating that males upregulate sperm production in response to the presence of rivals. Our data suggest that males show plasticity in the rate of spermatogenesis that is adaptive in the context of a fluctuating sperm competition environment.
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Affiliation(s)
- Joshua P Moatt
- Department of Biology, University of York, York YO10 5DD, UK
| | - Calvin Dytham
- Department of Biology, University of York, York YO10 5DD, UK
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26
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Barrett LT, Evans JP, Gasparini C. The effects of perceived mating opportunities on patterns of reproductive investment by male guppies. PLoS One 2014; 9:e93780. [PMID: 24705713 PMCID: PMC3976321 DOI: 10.1371/journal.pone.0093780] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 03/07/2014] [Indexed: 11/19/2022] Open
Abstract
Males pay considerable reproductive costs in acquiring mates (precopulatory sexual selection) and in producing ejaculates that are effective at fertilising eggs in the presence of competing ejaculates (postcopulatory sexual selection). Given these costs, males must balance their reproductive investment in a given mating to optimise their future reproductive potential. Males are therefore expected to invest in reproduction prudently according to the likelihood of obtaining future matings. In this study we tested this prediction by determining whether male reproductive investment varies with expected future mating opportunities, which were experimentally manipulated by visually exposing male guppies (Poecilia reticulata) to high or low numbers of females in the absence of competing males. Our experiment did not reveal consistent effects of perceived future mating opportunity on either precopulatory (male mate choice and mating behaviour) or postcopulatory (sperm quality and quantity) investment. However, we did find that male size and female availability interacted to influence mating behaviour; large males visually deprived of females during the treatment phase became more choosy and showed greater interest in their preferred female than those given continuous visual access to females. Overall, our results suggest males tailor pre- rather than postcopulatory traits according to local female availability, but critically, these effects depend on male size.
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Affiliation(s)
- Luke T. Barrett
- Centre for Evolutionary Biology, School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Jonathan P. Evans
- Centre for Evolutionary Biology, School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Clelia Gasparini
- Centre for Evolutionary Biology, School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia
- * E-mail:
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27
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Worthington AM, Gress BE, Neyer AA, Kelly CD. Do male crickets strategically adjust the number and viability of their sperm under sperm competition? Anim Behav 2013. [DOI: 10.1016/j.anbehav.2013.04.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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28
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Firman RC, Klemme I, Simmons LW. Strategic adjustments in sperm production within and between two island populations of house mice. Evolution 2013; 67:3061-70. [PMID: 24094355 DOI: 10.1111/evo.12164] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Accepted: 04/18/2013] [Indexed: 11/28/2022]
Abstract
Sperm production is physiologically costly. Consequently, males are expected to be prudent in their sperm production, and tailor their expenditure according to prevailing social conditions. Differences in sperm production have been found across island populations of house mice that differ in the level of selection from sperm competition. Here, we determined the extent to which these differences represent phenotypic plasticity and/or population divergence in sperm production. We sourced individuals from two populations at the extreme levels of sperm competition, and raised them under common-garden conditions while manipulating the social experience of developing males. Males from the high-sperm competition population produced more sperm and better quality sperm than did males from the low-sperm competition population. In addition, males reared under a perceived "risk" of sperm competition produced greater numbers of sperm than males reared with "no risk." However, our analyses revealed that phenotypic plasticity in sperm production was greater for individuals from the high-sperm competition population. Our results are thus consistent with both population divergence and phenotypic plasticity in sperm production, and suggest that population level of sperm competition might affect the degree of adaptive plasticity in sperm production in response to sperm competition risk.
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Affiliation(s)
- Renée C Firman
- Centre for Evolutionary Biology, School of Animal Biology (M092), University of Western Australia, Nedlands, 6009, Australia.
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29
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Experience affects mating behavior, but does not impact parental reproductive allocation in a lizard. Behav Ecol Sociobiol 2013. [DOI: 10.1007/s00265-013-1523-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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30
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Klemme I, Firman RC. Male house mice that have evolved with sperm competition have increased mating duration and paternity success. Anim Behav 2013. [DOI: 10.1016/j.anbehav.2013.01.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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31
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Kvarnemo C, Simmons LW. Polyandry as a mediator of sexual selection before and after mating. Philos Trans R Soc Lond B Biol Sci 2013; 368:20120042. [PMID: 23339234 PMCID: PMC3576577 DOI: 10.1098/rstb.2012.0042] [Citation(s) in RCA: 163] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
The Darwin–Bateman paradigm recognizes competition among males for access to multiple mates as the main driver of sexual selection. Increasingly, however, females are also being found to benefit from multiple mating so that polyandry can generate competition among females for access to multiple males, and impose sexual selection on female traits that influence their mating success. Polyandry can reduce a male's ability to monopolize females, and thus weaken male focused sexual selection. Perhaps the most important effect of polyandry on males arises because of sperm competition and cryptic female choice. Polyandry favours increased male ejaculate expenditure that can affect sexual selection on males by reducing their potential reproductive rate. Moreover, sexual selection after mating can ameliorate or exaggerate sexual selection before mating. Currently, estimates of sexual selection intensity rely heavily on measures of male mating success, but polyandry now raises serious questions over the validity of such approaches. Future work must take into account both pre- and post-copulatory episodes of selection. A change in focus from the products of sexual selection expected in males, to less obvious traits in females, such as sensory perception, is likely to reveal a greater role of sexual selection in female evolution.
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Affiliation(s)
- Charlotta Kvarnemo
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden.
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32
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Vaughn AA, Delbarco-Trillo J, Ferkin MH. Re-feeding food-deprived male meadow voles affects the sperm allocation of their rival males. Ethology 2012. [PMID: 23185098 DOI: 10.1111/eth.12016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
An individual's nutritional status affects the manner in which same- and opposite-sex conspecifics respond to that individual, which may affect their fitness. Male meadow voles, Microtus pennsylvanicus, increase their sperm allocation if they encounter the scent mark of an unfamiliar male that is not nutritionally challenged. If, however, the scent mark comes from a male that has been food deprived for 24 hours, stud male voles do not increase their sperm allocation. Food deprived males may be viewed as being lower quality and a reduced risk of sperm competition by rival males. We hypothesized that stud males in promiscuous mating systems tailor their sperm allocations depending on whether rival males have been food deprived and then re-fed. We predicted that newly re-fed males will be considered a strong risk of sperm competition because of the potentially high fitness and survival costs associated with food deprivation in males, and that they will cause stud males to increase their sperm allocation. Our results, however, showed that the recovery period from 24 hours of food deprivation was a relatively slow process. It took between 96 hours and 336 hours of re-feeding male scent donors that were food deprived for 24 hours to induce stud males to increase their sperm allocation to levels comparable to when scent donors were not food deprived. Stud male voles may be conserving the amount of sperm allocated until the male scent donors have recovered from food deprivation and subsequent re-feeding.
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Affiliation(s)
- Ashlee A Vaughn
- Department of Biological Sciences, The University of Memphis, Ellington Hall, Memphis TN 38152, USA
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33
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Price TAR, Lizé A, Marcello M, Bretman A. Experience of mating rivals causes males to modulate sperm transfer in the fly Drosophila pseudoobscura. JOURNAL OF INSECT PHYSIOLOGY 2012; 58:1669-1675. [PMID: 23085556 DOI: 10.1016/j.jinsphys.2012.10.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 10/08/2012] [Accepted: 10/09/2012] [Indexed: 06/01/2023]
Abstract
Male responses to risk of sperm competition play an important role in sexual selection, sexual conflict, and the evolution of mating systems. Such responses can combine behavioural and physiological processes, and can be mediated through different components of the ejaculate such as sperm numbers and seminal proteins. An additional level of ejaculate complexity is sperm heteromorphism, with the inclusion of non-fertilising parasperm in the ejaculate. We now test the response to rivals in a sperm heteromorphic species, Drosophila pseudoobscura, measuring the behavioural response and sperm transfer and, crucially, relating these to short-term fitness. Males respond to exposure to conspecific rivals by increasing mating duration, but do not respond to heterospecific rivals. In addition, after exposure to a conspecific rival, males increased the transfer of fertilising eusperm, but not non-fertilising parasperm. Males exposed to a conspecific rival also achieve higher offspring production. This suggests that the evolution of parasperm in flies was not driven by sperm competition and adds to the increasing evidence that males can make extremely sophisticated responses to mating competition.
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Affiliation(s)
- Tom A R Price
- Biosciences, University of Exeter, Cornwall Campus, UK
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34
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Abstract
Females frequently mate with several males, whose sperm then compete to fertilize available ova. Sperm competition represents a potent selective force that is expected to shape male expenditure on the ejaculate. Here, we review empirical data that illustrate the evolutionary consequences of sperm competition. Sperm competition favors the evolution of increased testes size and sperm production. In some species, males appear capable of adjusting the number of sperm ejaculated, depending on the perceived levels of sperm competition. Selection is also expected to act on sperm form and function, although the evidence for this remains equivocal. Comparative studies suggest that sperm length and swimming speed may increase in response to selection from sperm competition. However, the mechanisms driving this pattern remain unclear. Evidence that sperm length influences sperm swimming speed is mixed and fertilization trials performed across a broad range of species demonstrate inconsistent relationships between sperm form and function. This ambiguity may in part reflect the important role that seminal fluid proteins (sfps) play in affecting sperm function. There is good evidence that sfps are subject to selection from sperm competition, and recent work is pointing to an ability of males to adjust their seminal fluid chemistry in response to sperm competition from rival males. We argue that future research must consider sperm and seminal fluid components of the ejaculate as a functional unity. Research at the genomic level will identify the genes that ultimately control male fertility.
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Affiliation(s)
- Leigh W Simmons
- Centre for Evolutionary Biology, , School of Animal Biology (M092), The University of Western Australia, Crawley, Western Australia 6009, Australia.
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35
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Engqvist L. Evolutionary Modeling Predicts a Decrease in Postcopulatory Sperm Viability as a Response to Increasing Levels of Sperm Competition. Am Nat 2012; 179:667-77. [DOI: 10.1086/665000] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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36
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LEMAÎTRE JF, RAMM SA, HURST JL, STOCKLEY P. Sperm competition roles and ejaculate investment in a promiscuous mammal. J Evol Biol 2012; 25:1216-25. [DOI: 10.1111/j.1420-9101.2012.02511.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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37
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Barbosa F. Males responding to sperm competition cues have higher fertilization success in a soldier fly. Behav Ecol 2012. [DOI: 10.1093/beheco/ars035] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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38
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39
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Jeswiet SB, Lee-Jenkins SS, Godin JGJ. Concurrent effects of sperm competition and female quality on male mate choice in the Trinidadian guppy (Poecilia reticulata). Behav Ecol 2011. [DOI: 10.1093/beheco/arr175] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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40
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Bretman A, Gage MJG, Chapman T. Quick-change artists: male plastic behavioural responses to rivals. Trends Ecol Evol 2011; 26:467-73. [PMID: 21680050 DOI: 10.1016/j.tree.2011.05.002] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 05/03/2011] [Accepted: 05/03/2011] [Indexed: 11/26/2022]
Abstract
Behavioural plasticity allows animals to attune their behaviour to rapid environmental changes. Here we focus on plasticity in male mating behaviour in response to socio-sexual conditions. We discuss existing theory, generate predictions to facilitate exploration of the benefits of plastic behaviour, and identify parameters with the highest leverage on fitness. Existing data are synthesised to assess whether plasticity occurs pre- and post-copulation, to determine the direction of changes in behaviour, and to examine if plastic behaviour is fully flexible. We find that plasticity in males is widespread and not dominated by responses that occur pre- or post-copulation. Our synthesis also highlights areas that are underexplored, such as the limited data on the ultimate fitness consequences of such plastic behaviour.
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Affiliation(s)
- Amanda Bretman
- School of Biological Sciences, University of East Anglia, Norwich NR47TJ, UK.
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41
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Delbarco-Trillo J. Adjustment of sperm allocation under high risk of sperm competition across taxa: a meta-analysis. J Evol Biol 2011; 24:1706-14. [PMID: 21569157 DOI: 10.1111/j.1420-9101.2011.02293.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Sperm competition theory predicts that under high risk of sperm competition, males will increase the number of sperm that they allocate to a female. This prediction has been supported by some experimental studies but not by others. Here, I conducted a meta-analysis to determine whether the increase in sperm allocation under high risk of sperm competition is a generalized response across taxa. I collected data from 39 studies and 37 species. Across taxa, males under a high risk of sperm competition respond by increasing their sperm allocation (mean effect size=0.32). Number of offspring did not explain a significant portion of the variation in effect sizes. A traditional meta-analysis (i.e. without phylogenetic information) described the variation among effect sizes better than a meta-analysis that incorporates the phylogenetic relationships among species, suggesting that the increase in sperm allocation under high risk of sperm competition is similarly prevalent across taxa.
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Affiliation(s)
- J Delbarco-Trillo
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA.
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42
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Demont M, Buser CC, Martin OY, Bussière LF. Natural levels of polyandry: differential sperm storage and temporal changes in sperm competition intensity in wild yellow dung flies. Funct Ecol 2011. [DOI: 10.1111/j.1365-2435.2011.01861.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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43
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Abstract
Sperm competition was identified in 1970 as a pervasive selective force in post-copulatory sexual selection that occurs when the ejaculates of different males compete to fertilise a given set of ova. Since then, sperm competition has been much studied both empirically and theoretically. Because sperm competition often favours large ejaculates, an important challenge has been to understand the evolution of strategies through which males invest in sperm production and economise sperm allocation to maximise reproductive success under competitive conditions. Sperm competition mechanisms vary greatly, depending on many factors including the level of sperm competition, space constraints in the sperm competition arena, male mating roles, and female influences on sperm utilisation. Consequently, theoretical models of ejaculate economics are complex and varied, often with apparently conflicting predictions. The goal of this review is to synthesise the theoretical basis of ejaculate economics under sperm competition, aiming to provide empiricists with categorised model assumptions and predictions. We show that apparent contradictions between older and newer models can often be reconciled and there is considerable consensus in the predictions generated by different models. We also discuss qualitative empirical support for some of these predictions, and detail quantitative matches between predictions and observations that exist in the yellow dung fly. We argue that ejaculate economic theory represents a powerful heuristic to explain the diversity in ejaculate traits at multiple levels: across species, across males and within individual males. Future progress requires greater understanding of sperm competition mechanisms, quantification of trade-offs between ejaculate allocation and numbers of matings gained, further knowledge of mechanisms of female sperm selection and their associated costs, further investigation of non-sperm ejaculate effects, and theoretical integration of pre- and post-copulatory episodes of sexual selection.
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Affiliation(s)
- Geoff A Parker
- Division of Population and Evolutionary Biology, School of Biological Sciences, Crown Street, University of Liverpool, Liverpool, L69 7ZB, UK.
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44
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Kelly CD, Jennions MD. Sexual selection and sperm quantity: meta-analyses of strategic ejaculation. Biol Rev Camb Philos Soc 2011; 86:863-84. [PMID: 21414127 DOI: 10.1111/j.1469-185x.2011.00175.x] [Citation(s) in RCA: 214] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Clint D Kelly
- Department of Ecology, Evolution & Organismal Biology, Iowa State University, Ames, USA.
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45
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Jeswiet SB, Lee-Jenkins SS, Ramnarine IW, Godin JGJ. Sperm competition risk and mate choice in male Trinidadian guppies, Poecilia reticulata. Anim Behav 2011. [DOI: 10.1016/j.anbehav.2010.12.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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46
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Nandy B, Prasad NG. Reproductive behavior and fitness components in male Drosophila melaogaster are non-linearly affected by the number of male co-inhabitants early in adult life. JOURNAL OF INSECT SCIENCE (ONLINE) 2011; 11:67. [PMID: 21867434 PMCID: PMC3281429 DOI: 10.1673/031.011.6701] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Accepted: 07/15/2010] [Indexed: 05/31/2023]
Abstract
Although multiple lines of evidence suggest that early adult life is very important in shaping the reproductive behavior of males, few studies have looked at the fitness consequences of the variation in reproductive behavior induced by differences in early life experience of males. Using a long term laboratory adapted population of Drosophila melanogaster Meigen (Diptera: Drosophilidae), early life experience, in terms of co-inhabitant numbers, was found to affect male mating behavior and at least one fitness component. However, in contrast to previous studies, a non-linear relationship was found between early life experience and fitness components and a significant effect of co-inhabitant number on copulation duration and sperm defense. Both these traits showed a sharp increase as the co-inhabitant numbers changed from 1 to 16. However, there was a decline in the trait values as the co-inhabitant number increased further. The probable causes for the observed non-linear pattern of responses are discussed.
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Affiliation(s)
- B. Nandy
- Indian Institute of Science Education and Research Mohali, MGSIPA Complex, Sector 26, Chandigarh 160 019, India
| | - N. G. Prasad
- Indian Institute of Science Education and Research Mohali, MGSIPA Complex, Sector 26, Chandigarh 160 019, India
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47
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Edward DA, Fricke C, Chapman T. Adaptations to sexual selection and sexual conflict: insights from experimental evolution and artificial selection. Philos Trans R Soc Lond B Biol Sci 2010; 365:2541-8. [PMID: 20643744 PMCID: PMC2935098 DOI: 10.1098/rstb.2010.0027] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Artificial selection and experimental evolution document natural selection under controlled conditions. Collectively, these techniques are continuing to provide fresh and important insights into the genetic basis of evolutionary change, and are now being employed to investigate mating behaviour. Here, we focus on how selection techniques can reveal the genetic basis of post-mating adaptations to sexual selection and sexual conflict. Alteration of the operational sex ratio of adult Drosophila over just a few tens of generations can lead to altered ejaculate allocation patterns and the evolution of resistance in females to the costly effects of elevated mating rates. We provide new data to show how male responses to the presence of rivals can evolve. For several traits, the way in which males responded to rivals was opposite in lines selected for male-biased, as opposed to female-biased, adult sex ratio. This shows that the manipulation of the relative intensity of intra- and inter-sexual selection can lead to replicable and repeatable effects on mating systems, and reveals the potential for significant contemporary evolutionary change. Such studies, with important safeguards, have potential utility for understanding sexual selection and sexual conflict across many taxa. We discuss how artificial selection studies combined with genomics will continue to deepen our knowledge of the evolutionary principles first laid down by Darwin 150 years ago.
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Affiliation(s)
| | | | - Tracey Chapman
- School of Biological Sciences, University of East Anglia, Norwich, Norfolk NR4 7TJ, UK
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Kelly CD, Bussière LF, Gwynne DT. Pairing and insemination patterns in a giant weta (Deinacrida rugosa: Orthoptera; Anostostomatidae). J ETHOL 2010. [DOI: 10.1007/s10164-010-0211-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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49
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Alonzo S, Pizzari T. Male Fecundity Stimulation: Conflict and Cooperation Within and Between the Sexes: Model Analyses and Coevolutionary Dynamics. Am Nat 2010; 175:174-85. [DOI: 10.1086/649596] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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50
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Bretman A, Fricke C, Hetherington P, Stone R, Chapman T. Exposure to rivals and plastic responses to sperm competition in Drosophila melanogaster. Behav Ecol 2010. [DOI: 10.1093/beheco/arp189] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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