1
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Jobson S, Hamel JF, Mercier A. Shake it off: exploring drivers and outcomes of autotomy in marine invertebrates. Biol Lett 2024; 20:20240015. [PMID: 38807548 PMCID: PMC11285939 DOI: 10.1098/rsbl.2024.0015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 03/13/2024] [Accepted: 04/03/2024] [Indexed: 05/30/2024] Open
Abstract
Autotomy refers to self-amputation where the loss of a limb or organ is generally said to be (1) in response to stressful external stimuli; (2) voluntary and nervously mediated; (3) supported by adaptive features that increase efficiency and simultaneously mediate the cost; and (4) morphologically delineated by a predictable breakage plane. It is estimated that this phenomenon has evolved independently nine different times across the animal kingdom, appearing in many different taxa, including vertebrate and invertebrate as well as aquatic and terrestrial animals. Marine invertebrates use this behaviour in a diversity of manners that have yet to be globally reviewed and critically examined. Here, published data from marine invertebrate taxa were used to explore instances of injury as an evolutionary driver of autotomy. Findings suggest that phyla (e.g. Echinodermata and Arthropoda) possibly experiencing high rates of injury (tissue damage or loss) are more likely to be able to perform autotomy. Additionally, this review looks at various morphological, physiological and environmental conditions that have either driven the evolution or maintained the behaviour of autotomy in marine invertebrates. Finally, the use of autotomic abilities in the development of more sustainable and less ecologically invasive fisheries is explored.
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Affiliation(s)
- Sara Jobson
- Department of Ocean Sciences, Memorial University, St John’s (Newfoundland and Labrador), Canada
| | - Jean-François Hamel
- Society for the Exploration and Valuing of the Environment, St Philips (Newfoundland and Labrador), Canada
| | - Annie Mercier
- Department of Ocean Sciences, Memorial University, St John’s (Newfoundland and Labrador), Canada
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2
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Jiang H, Zhan Y, Wu Q, Zhang H, Kuntner M, Tu L. A spider mating plug functions to protect sperm. PLoS One 2024; 19:e0301290. [PMID: 38551985 PMCID: PMC10980215 DOI: 10.1371/journal.pone.0301290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 03/13/2024] [Indexed: 04/01/2024] Open
Abstract
Mating plugs in animals are ubiquitous and are commonly interpreted to be products of mating strategies. In spiders, however, mating plugs may also take on functions beyond female remating prevention. Due to the vagaries of female genital (spermathecal) anatomy, most spiders face the problem of having to secure additional, non-anatomical, protection for transferred sperm. Here, we test the hypothesis that mating plugs, rather than (or in addition to) being adaptations for mating strategies, may serve as sperm protection mechanism. Based on a comparative study on 411 epigyna sampled from 36 families, 187 genera, 330 species of entelegyne spiders, our results confirm the necessity of a sperm protection mechanism. We divided the entelegyne spermathecae into four types: SEG, SED, SCG and SCD. We also studied detailed morphology of epigynal tracts in the spider Diphya wulingensis having the SEG type spermathecae, using 3D-reconstruction based on semi thin histological series section. In this species, we hypothesize that two distinct types of mating plug, the sperm plug and the secretion plug, serve different functions. Morphological details support this: sperm plugs are formed on a modified spermathecal wall by the spilled sperm, and function as a temporary protection mechanism to prevent sperm from leaking and desiccating, while secretion plugs function in postcopulation both as a permanent protection mechanism, and to prevent additional mating. Furthermore, with the modified spermathecal wall of S2 stalk, the problem of shunt of sperm input and output, and the possibility of female multiple mating have been resolved. Variation in spermathecal morphology also suggests that the problem of sperm protection might be resolved in different ways in spiders. Considering mating plugs of varying shapes and origins in the vast morphospace of spiders, we conclude that mating plugs might serve different purposes that relate both to mating strategies, as well as to sperm protection.
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Affiliation(s)
- He Jiang
- College of Life Sciences, Capital Normal University, Beijing, P. R. China
| | - Yongjia Zhan
- College of Life Sciences, Capital Normal University, Beijing, P. R. China
| | - Qingqing Wu
- Lang Yue Campus of Beijing 12th High School, Beijing, P. R. China
| | - Huitao Zhang
- Beijing Advanced Innovation Center for Imaging Technology, Capital Normal University, Beijing, P. R. China
| | - Matjaž Kuntner
- Department of Organisms and Ecosystems Research, National Institute of Biology, Ljubljana, Slovenia
- Jovan Hadži Institute of Biology, ZRC SAZU, Ljubljana, Slovenia
- State Key Laboratory of Biocatalysis and Enzyme Engineering & Centre for Behavioural Ecology & Evolution, School of Life Sciences, Hubei University, Wuhan, China
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC, United States of America
| | - Lihong Tu
- College of Life Sciences, Capital Normal University, Beijing, P. R. China
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3
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Houston AI, Fromhage L, McNamara JM. A general framework for modelling trade-offs in adaptive behaviour. Biol Rev Camb Philos Soc 2024; 99:56-69. [PMID: 37609707 DOI: 10.1111/brv.13011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 08/05/2023] [Accepted: 08/09/2023] [Indexed: 08/24/2023]
Abstract
An animal's behaviour can influence many variables, such as its energy reserves, its risk of injury or mortality, and its rate of reproduction. To identify the optimal action in a given situation, these various effects can be compared in the common currency of reproductive value. While this idea has been widely used to study trade-offs between pairs of variables, e.g. between energy gain versus survival, here we present a unified framework that makes explicit how these various trade-offs fit together. This unification covers a wide range of biological phenomena, highlighting similarities in their logical structure and helping to identify knowledge gaps. To fill one such gap, we present a new model of foraging under the risk of predation and damage accumulation. We conclude by discussing the use and limitations of state-dependent optimisation theory in predicting biological observations.
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Affiliation(s)
- Alasdair I Houston
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - Lutz Fromhage
- University of Jyväskylä, PO Box 35, Jyväskylä, 40014, Finland
| | - John M McNamara
- School of Mathematics, University of Bristol, Fry Building, Woodland Road, Bristol, BS8 1UG, UK
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4
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Morgan WH, Palmer SCF, Lambin X. Mating system induced lags in rates of range expansion for different simulated mating systems and dispersal strategies: a modelling study. Oecologia 2024; 204:119-132. [PMID: 38172416 PMCID: PMC10830608 DOI: 10.1007/s00442-023-05492-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 11/25/2023] [Indexed: 01/05/2024]
Abstract
Mismatches between current and potential species distributions are commonplace due to lags in the response of populations to changing environmental conditions. The prevailing mating system may contribute to such lags where it leads to mating failure at the range edge, but how active dispersers might mitigate these lags using social information to inform dispersal strategies warrants greater exploration. We used an individual-based model to explore how different mating systems for species that actively search for habitat can impose a filter on the ability to colonise empty, fragmented landscapes, and explored how using social information during dispersal can mitigate the lags caused by more constrained mating systems. The mate-finding requirements implemented in two-sex models consistently led to slower range expansion compared to those that were not mate limited (i.e., female only models), even when mating was polygynous. A mate-search settlement strategy reduced the proportion of unmated females at the range edge but had little impact on rate of spread. In contrast, a negative density-dependent settlement strategy resulted in much faster spread, which could be explained by a greater number of long-distance dispersal events. Our findings suggest that even low rates of mating failure at the range edge can lead to considerable lags in range expansion, though dispersal strategies that favour colonising more distant, sparsely occupied habitat patches may effectively mitigate these lags.
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Affiliation(s)
- W H Morgan
- School of Biological Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen, AB24 2TZ, UK.
| | - S C F Palmer
- School of Biological Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen, AB24 2TZ, UK
| | - X Lambin
- School of Biological Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen, AB24 2TZ, UK
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5
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Bisshop A. Arachnomadology: A Zoētic Framework for Queering Stories of Spider Sex, Life, and Death. AUSTRALIAN FEMINIST STUDIES 2022. [DOI: 10.1080/08164649.2022.2051165] [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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6
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Escalante I, Elias DO. The type of leg lost affects habitat use but not survival in a non-regenerating arthropod. Ecol Evol 2021; 11:10672-10685. [PMID: 34367605 PMCID: PMC8328409 DOI: 10.1002/ece3.7879] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 06/17/2021] [Accepted: 06/21/2021] [Indexed: 12/03/2022] Open
Abstract
Finding shelter and surviving encounters with predators are pervasive challenges for animals. These challenges may be exacerbated after individuals experience bodily damage. Certain forms of damage arise voluntarily in animals; for instance, some taxa release appendages (tails, legs, or other body parts) as a defensive strategy ("autotomy"). This behavior, however, may pose long-term negative consequences for habitat use and survival. Additionally, these putative consequences are expected to vary according to the function of the lost body part. We tested the effects of losing different functional leg types (locomotor or sensory) on future habitat use and survival in a Neotropical species of Prionostemma harvestmen (Arachnida: Opiliones) that undergo frequent autotomy but do not regrow limbs. Daytime surveys revealed that both eight-legged harvestmen and harvestmen missing legs roosted in similar frequencies across habitats (tree bark, mossy tree, or fern), and perched at similar heights. Mark-recapture data showed that harvestmen that lost sensory legs roosted in tree bark less frequently, but on mossy trees more frequently. On the contrary, we did not observe changes in habitat use for eight-legged animals or animals that lost locomotor legs. This change might be related to sensory exploration and navigation. Lastly, we found that recapture rates across substrates were not affected by the type of legs lost, suggesting that leg loss does not impact survival. This potential lack of effect might play a role in why a defensive strategy like autotomy is so prevalent in harvestmen despite the lack of regeneration.
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Affiliation(s)
- Ignacio Escalante
- Department of Environmental Sciences, Policy, & ManagementUniversity of California ‐ BerkeleyCAUSA
- Present address:
Behavioral & Molecular Ecology GroupDepartment of Biological SciencesUniversity of Wisconsin – MilwaukeeMilwaukeeWIUSA
| | - Damian O. Elias
- Department of Environmental Sciences, Policy, & ManagementUniversity of California ‐ BerkeleyCAUSA
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7
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Tuni C, Schneider J, Uhl G, Herberstein ME. Sperm competition when transfer is dangerous. Philos Trans R Soc Lond B Biol Sci 2020; 375:20200073. [PMID: 33070729 DOI: 10.1098/rstb.2020.0073] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Aggressive and cannibalistic female spiders can impose strong selection on male mating and fertilization strategies. Furthermore, the distinctive reproductive morphology of spiders is predicted to influence the outcome of sperm competition. Polyandry is common in spiders, leading to defensive male strategies that include guarding, plugging and self-sacrifice. Paternity patterns are highly variable and unlikely to be determined solely by mating order, but rather by relative copulation duration, deployment of plugs and cryptic female choice. The ability to strategically allocate sperm is limited, either by the need to refill pedipalps periodically or owing to permanent sperm depletion after mating. Further insights now rely on unravelling several proximate mechanisms such as the process of sperm activation and the role of seminal fluids. This article is part of the theme issue 'Fifty years of sperm competition'.
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Affiliation(s)
- Cristina Tuni
- Department of Biology II, Ludwig-Maximilians University of Munich, Planegg-Martinsried, Munich, Germany
| | - Jutta Schneider
- Institute of Zoology, University of Hamburg, Martin-Luther-King Platz 3, Hamburg 20146 Germany
| | - Gabriele Uhl
- General and Systematic Zoology, University of Greifswald, Bachstrasse 11/13, Greifswald 17489, Germany
| | - Marie E Herberstein
- Department of Biological Sciences, Macquarie University, North Ryde, Sydney NSW 2109, Australia
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8
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Fisher AM, Cornell SJ, Holwell GI, Price TAR. Mate‐finding Allee effects can be exacerbated or relieved by sexual cannibalism. J Anim Ecol 2020; 89:1581-1592. [DOI: 10.1111/1365-2656.13214] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 02/21/2020] [Indexed: 11/30/2022]
Affiliation(s)
- Adam M. Fisher
- Institute of Integrative Biology University of Liverpool Liverpool UK
| | | | | | - Tom A. R. Price
- Institute of Integrative Biology University of Liverpool Liverpool UK
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9
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Oviedo‐Diego MA, Mattoni CI, Vrech DE, Michalik P, Peretti AV. The morphology of mating plugs and its formation in scorpions: Implications for intersexual participation. J Morphol 2020; 281:620-635. [DOI: 10.1002/jmor.21125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/24/2020] [Accepted: 03/26/2020] [Indexed: 11/11/2022]
Affiliation(s)
- Mariela 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
| | - Camilo I. Mattoni
- 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
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Físicas y Naturales, Departamento de Diversidad Biológica y Ecología Córdoba Argentina
| | - David 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
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Físicas y Naturales, Departamento de Diversidad Biológica y Ecología Córdoba Argentina
| | - Peter Michalik
- Zoological Institute and Museum, Universität Greifswald Greifswald Germany
| | - Alfredo 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
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Físicas y Naturales, Departamento de Diversidad Biológica y Ecología Córdoba Argentina
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10
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11
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Balu R, Ramachandran SS, Paramasivam SG. Evidence for mouse sulfhydryl oxidase-assisted cross-linking of major seminal vesicle proteins. Mol Reprod Dev 2019; 86:1682-1693. [PMID: 31448842 DOI: 10.1002/mrd.23258] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 08/08/2019] [Indexed: 01/21/2023]
Abstract
Copulatory plug formation in animals is a general phenomenon by which competition is reduced among rival males. In mouse, the copulatory plug formation results from the coagulation of highly viscous seminal vesicle secretion (SVS) that is rich in proteins, such as dimers of SVS I, SVS I + II + III, and SVS II. These high-molecular-weight complexes (HMWCs) are also reported to be the bulk of proteins in the copulatory plug of the female mouse following copulation. In addition, mouse SVS contributes to the existence of sulfhydryl oxidase (Sox), which mediates the disulfide bond formation between cysteine residues. In this study, flavin adenine dinucleotide (FAD)-dependent Sox was purified from mouse SVS using ion exchange and high-performance liquid chromatography. The purified enzyme was identified to be Sox, based on western blot analysis with Sox antiserum and its capability of oxidizing dithiothreitol as substrate. The pH optima and thermal stability of the enzyme were determined. Among the metal ions tested, zinc showed an inhibitory effect on Sox activity. A prosthetic group of the enzyme was identified as FAD. The Km and Vmax of the enzyme was also determined. In addition to purification and biochemical characterization of seminal vesicle Sox, the major breakthrough of this study was proving its cross-linking activity among SVS I-III monomers to form HMWCs in SVS.
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Affiliation(s)
- Rubhadevi Balu
- Department of Biotechnology, BIT-Campus, Anna University, Tiruchirappalli, Tamil Nadu, India
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12
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Emberts Z, Escalante I, Bateman PW. The ecology and evolution of autotomy. Biol Rev Camb Philos Soc 2019; 94:1881-1896. [PMID: 31240822 DOI: 10.1111/brv.12539] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 05/29/2019] [Accepted: 06/04/2019] [Indexed: 01/29/2023]
Abstract
Autotomy, the self-induced loss of a body part, occurs throughout Animalia. A lizard dropping its tail to escape predation is an iconic example, however, autotomy occurs in a diversity of other organisms. Octopuses can release their arms, crabs can drop their claws, and bugs can amputate their legs. The diversity of organisms that can autotomize body parts has led to a wealth of research and several taxonomically focused reviews. These reviews have played a crucial role in advancing our understanding of autotomy within their respective groups. However, because of their taxonomic focus, these reviews are constrained in their ability to enhance our understanding of autotomy. Here, we aim to synthesize research on the ecology and evolution of autotomy throughout Animalia, building a unified framework on which future studies can expand. We found that the ability to drop an appendage has evolved multiple times throughout Animalia and that once autotomy has evolved, selection appears to act on the removable appendage to increase the efficacy and/or efficiency of autotomy. This could explain why some autotomizable body parts are so elaborate (e.g. brightly coloured). We also show that there are multiple benefits, and variable costs, associated with autotomy. Given this variation, we generate an economic theory of autotomy (modified from the economic theory of escape) which makes predictions about when an individual should resort to autotomy. Finally, we show that the loss of an autotomizable appendage can have numerous consequences on population and community dynamics. By taking this broad taxonomic approach, we identified patterns of autotomy that transcend specific lineages and highlight clear directions for future research.
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Affiliation(s)
- Zachary Emberts
- Department of Biology, University of Florida, 876 Newell Drive, Gainesville, FL, 32611, USA
| | - Ignacio Escalante
- Department of Environmental Sciences, Policy, & Management, University of California, 140 Mulford Hall, Berkeley, CA, 94720, USA
| | - Philip W Bateman
- Behavioural Ecology Lab, School of Molecular and Life Sciences, Curtin University, Perth, WA, 6845, Australia
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13
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Oviedo-Diego MA, Mattoni CI, Peretti AV. Specificity of the female's local cellular immune response in genital plug producing scorpion species. PLoS One 2019; 14:e0208682. [PMID: 30742645 PMCID: PMC6370188 DOI: 10.1371/journal.pone.0208682] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/30/2019] [Indexed: 02/05/2023] Open
Abstract
Immune defense is a key feature in the life history of organisms, expensive to maintain, highly regulated by individuals and exposed to physiological and evolutionary trade-offs. In chelicerates, relatively scarce are the studies that relate postcopulatory mechanisms and immune response parameters. This work makes an approximation to the female’s immunological consequences produced after the placement of a foreign body in the genitalia of three scorpions species, two species that normally receive genital plugs during mating (Urophonius brachycentrus and U. achalensis) and one that does not (Zabius fuscus). Here we performed the first morphological description of the natural plugs of the two Urophonius species. We described complex three zoned structure anchored to the female genital atrium and based on this information we placed implants in the genitalia (for eliciting the local immune response) of virgin females of the three species and measured the immune encapsulation response to this foreign body. We found a greater and heterogeneous response in different zones of the implants in the plug producing species. To corroborate the specificity of this immune response, we compared the local genital reaction with the triggered response at a systemic level by inserting implants into the female body cavity of U. brachycentrus and Zabius fuscus. We found that the systemic response did not differ between species and that only in the plug producing species the local response in the genitalia was higher than the systemic one. We also compared the total hemocyte load before and after the genital implantation to see if this parameter was compromised by the immunological challenge. We confirmed that in Urophonius species the presence of a strange body in the genitalia caused a decrease in the hemocyte load. Besides, we find correlations between the body weight and the immunological parameters, as well as between different immunological parameters with each other. Complementarily, we characterized the hemocytes of the three scorpion species for the first time. This comparative study can help to provide a wider framework of the immunological characteristics of the species, their differences and their relationship with the particular postcopulatory mechanism such as the genital plugs.
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Affiliation(s)
- Mariela A. Oviedo-Diego
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Diversidad Biológica y Ecología, Córdoba Capital, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Laboratorio de Biología Reproductiva y Evolución, Córdoba Capital, Cordoba, Argentina
- * E-mail:
| | - Camilo I. Mattoni
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Diversidad Biológica y Ecología, Córdoba Capital, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Laboratorio de Biología Reproductiva y Evolución, Córdoba Capital, Cordoba, Argentina
| | - Alfredo V. Peretti
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Diversidad Biológica y Ecología, Córdoba Capital, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Laboratorio de Biología Reproductiva y Evolución, Córdoba Capital, Cordoba, Argentina
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14
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Townsend VR, Pérez-González A, Proud DN. Putative mating plugs of harvestmen (Opiliones, Laniatores). ZOOL ANZ 2019. [DOI: 10.1016/j.jcz.2018.12.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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15
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Andrade MC. Sexual selection and social context: Web-building spiders as emerging models for adaptive plasticity. ADVANCES IN THE STUDY OF BEHAVIOR 2019. [DOI: 10.1016/bs.asb.2019.02.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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16
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Sentenská L, Pekár S, Uhl G. Deposition, removal and production site of the amorphous mating plug in the spider Philodromus cespitum. Naturwissenschaften 2018; 105:50. [PMID: 30030630 DOI: 10.1007/s00114-018-1575-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 06/28/2018] [Accepted: 07/06/2018] [Indexed: 10/28/2022]
Abstract
In order to avoid sperm competition, males of many taxa apply physical barriers, so-called mating plugs, into female genitalia. Females may control which males deposit a plug through pre-copulatory mate choice or by influencing plug efficacy to avoid costs imposed by plugging. However, subsequent suitors might remove the plugs. We investigated behavioural and morphological aspects of plug deposition and removal in a promiscuous spider, Philodromus cespitum (Philodromidae). We performed mating trials to investigate factors affecting plugging. To identify the plug origin, we conducted a morphological analysis using 3D X-ray microtomography and histology of the male copulatory organ and the female genital tract. In P. cespitum, the plug material is produced in the male genital bulb and transferred to the female together with sperm. The copulation is brief and terminated by the female. After mating, plugging material was found in the genital atrium of all females, covering it to a varying degree (10-100%). The extent of coverage was associated with the duration of movements of male copulatory organ connected with sperm transfer (i.e. full haematodochal expansions) and with the number of taps a male delivered with his legs to the female during courtship. Males larger than the female performed more tapping movements. Mating trials with plugged females revealed that males could remove plugs partly or entirely. Removal success increased with increasing foreleg length ratio between the male who removed the plug and the one who deposited it. We discuss our results in the light of the potential female control of plug deposition and removal.
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Affiliation(s)
- Lenka Sentenská
- Department of Botany and Zoology, Masaryk University, Brno, Czech Republic.
| | - Stano Pekár
- Department of Botany and Zoology, Masaryk University, Brno, Czech Republic.
| | - Gabriele Uhl
- Zoological Institute and Museum, Department of General and Systematic Zoology, University of Greifswald, Greifswald, Germany.
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17
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Fisher AM, Cornell SJ, Holwell GI, Price TAR. Sexual cannibalism and population viability. Ecol Evol 2018; 8:6663-6670. [PMID: 30038765 PMCID: PMC6053559 DOI: 10.1002/ece3.4155] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 02/27/2018] [Accepted: 03/07/2018] [Indexed: 12/02/2022] Open
Abstract
Some behaviours that typically increase fitness at the individual level may reduce population persistence, particularly in the face of environmental changes. Sexual cannibalism is an extreme mating behaviour which typically involves a male being devoured by the female immediately before, during or after copulation, and is widespread amongst predatory invertebrates. Although the individual-level effects of sexual cannibalism are reasonably well understood, very little is known about the population-level effects. We constructed both a mathematical model and an individual-based model to predict how sexual cannibalism might affect population growth rate and extinction risk. We found that in the absence of any cannibalism-derived fecundity benefit, sexual cannibalism is always detrimental to population growth rate and leads to a higher population extinction risk. Increasing the fecundity benefits of sexual cannibalism leads to a consistently higher population growth rate and likely a lower extinction risk. However, even if cannibalism-derived fecundity benefits are large, very high rates of sexual cannibalism (>70%) can still drive the population to negative growth and potential extinction. Pre-copulatory cannibalism was particularly damaging for population growth rates and was the main predictor of growth declining below the replacement rate. Surprisingly, post-copulatory cannibalism had a largely positive effect on population growth rate when fecundity benefits were present. This study is the first to formally estimate the population-level effects of sexual cannibalism. We highlight the detrimental effect sexual cannibalism may have on population viability if (1) cannibalism rates become high, and/or (2) cannibalism-derived fecundity benefits become low. Decreased food availability could plausibly both increase the frequency of cannibalism, and reduce the fecundity benefit of cannibalism, suggesting that sexual cannibalism may increase the risk of population collapse in the face of environmental change.
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Affiliation(s)
- Adam M. Fisher
- Institute of Integrative BiologyUniversity of LiverpoolLiverpoolUK
| | | | | | - Tom A. R. Price
- Institute of Integrative BiologyUniversity of LiverpoolLiverpoolUK
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Smith DT, Clarke NVE, Boone JM, Fricke C, Chapman T. Sexual conflict over remating interval is modulated by the sex peptide pathway. Proc Biol Sci 2018; 284:rspb.2016.2394. [PMID: 28250180 PMCID: PMC5360916 DOI: 10.1098/rspb.2016.2394] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 02/06/2017] [Indexed: 11/12/2022] Open
Abstract
Sexual conflict, in which the evolutionary interests of males and females diverge, shapes the evolution of reproductive systems across diverse taxa. Here, we used the fruit fly to study sexual conflict in natural, three-way interactions comprising a female, her current and previous mates. We manipulated the potential for sexual conflict by using sex peptide receptor (SPR) null females and by varying remating from 3 to 48 h, a period during which natural rematings frequently occur. SPR-lacking females do not respond to sex peptide (SP) transferred during mating and maintain virgin levels of high receptivity and low fecundity. In the absence of SPR, there was a convergence of fitness interests, with all individuals gaining highest productivity at 5 h remating. This suggests that the expression of sexual conflict was reduced. We observed an unexpected second male-specific advantage to early remating, resulting from an increase in the efficiency of second male sperm use. This early window of opportunity for exploitation by second males depended on the presence of SPR. The results suggest that the SP pathway can modulate the expression of sexual conflict in this system, and show how variation in the selective forces that shape conflict and cooperation can be maintained.
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Affiliation(s)
- Damian T Smith
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Naomi V E Clarke
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - James M Boone
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Claudia Fricke
- Institute for Evolution and Biodiversity, University of Muenster, Huefferstr. 1, 48149 Muenster, Germany
| | - Tracey Chapman
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
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Cory AL, Schneider JM. Effects of social information on life history and mating tactics of males in the orb-web spider Argiope bruennichi. Ecol Evol 2017; 8:344-355. [PMID: 29321876 PMCID: PMC5756857 DOI: 10.1002/ece3.3672] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/03/2017] [Accepted: 11/08/2017] [Indexed: 01/14/2023] Open
Abstract
Informed mating decisions are often based on social cues providing information about prospective mating opportunities. Social information early in life can trigger developmental modifications and influence later mating decisions. A high adaptive value of such adjustments is particularly obvious in systems where potential mating rates are extremely limited and have to be carried out in a short time window. Males of the sexually cannibalistic spider Argiope bruennichi can achieve maximally two copulations which they can use for one (monogyny) or two females (bigyny). The choice between these male mating tactics should rely on female availability that males might assess through volatile sex pheromones emitted by virgin females. We predict that in response to those female cues, males of A. bruennichi should mature earlier and at a smaller body size and favor a bigynous mating tactic in comparison with controls. We sampled spiders from two areas close to the Southern and Northern species range to account for differences in mate quality and seasonality. In a fully factorial design, half of the subadult males from both areas obtained silk cues of females, while the other half remained without female exposure. Adult males were subjected to no‐choice mating tests and could either monopolize the female or leave her (bigyny). We found that Southern males matured later and at a larger size than Northern males. Regardless of their origin, males also shortened the subadult stage in response to female cues, which, however, had no effects on male body mass. Contrary to our prediction, the frequencies of mating tactics were unaffected by the treatment. We conclude that while social cues during late development elicit adaptive life history adjustments, they are less important for the adjustment of mating decisions. We suggest that male tactics mostly rely on local information at the time of mate search.
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Affiliation(s)
- Anna-Lena Cory
- Zoologisches Institut Universität Hamburg Hamburg Hamburg Germany
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Emberts Z, Miller CW, Kiehl D, St Mary CM. Cut your losses: self-amputation of injured limbs increases survival. Behav Ecol 2017; 28:1047-1054. [PMID: 29622925 PMCID: PMC5873245 DOI: 10.1093/beheco/arx063] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 03/24/2017] [Accepted: 04/04/2017] [Indexed: 11/17/2022] Open
Abstract
Autotomy, self-induced limb loss, is an extreme trait observed throughout the animal kingdom; lizards drop their tails, crickets release their legs, and crabs drop their claws. These repeated evolutionary origins suggest that autotomy is adaptive. Yet, we do not have a firm understanding of the selective pressures that promote and maintain this extreme trait. Although multiple adaptive hypotheses exist, research has generally focused on autotomy’s adaptive value as a form of predator escape. However, autotomy could also be selected to reduce the cost of an injured limb, which we investigate here. Previously, this alternative hypothesis has been challenging to directly test because when an injury occurs on an autotomizable limb, that limb is almost always dropped (i.e., autotomy is behaviorally fixed within populations). Recently, however, we have identified a species, Narnia femorata (Insecta: Hemiptera: Coreidae), where some individuals autotomize limbs in response to injury, but some do not. This natural variation allowed us to investigate both the survival costs of retaining an injured limb and the benefits of autotomizing it. In this study, we find a positive association between autotomizing injured limbs and survival, thereby quantifying a new and likely widespread benefit of autotomy—reducing the cost of injury.
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Affiliation(s)
- Zachary Emberts
- Department of Biology, University of Florida, 876 Newell Drive Gainesville, FL 32611, USA
| | - Christine W Miller
- Entomology and Nematology Department, University of Florida, 1881 Natural Area Drive Gainesville, FL 32611, USA
| | - Daniel Kiehl
- Department of Biology, University of Florida, 876 Newell Drive Gainesville, FL 32611, USA
| | - Colette M St Mary
- Department of Biology, University of Florida, 876 Newell Drive Gainesville, FL 32611, USA
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Herberstein ME, Painting CJ, Holwell GI. Scramble Competition Polygyny in Terrestrial Arthropods. ADVANCES IN THE STUDY OF BEHAVIOR 2017. [DOI: 10.1016/bs.asb.2017.01.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Kuntner M, Cheng RC, Kralj-Fišer S, Liao CP, Schneider JM, Elgar MA. The evolution of genital complexity and mating rates in sexually size dimorphic spiders. BMC Evol Biol 2016; 16:242. [PMID: 27829358 PMCID: PMC5103378 DOI: 10.1186/s12862-016-0821-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 10/28/2016] [Indexed: 11/10/2022] Open
Abstract
Background Genital diversity may arise through sexual conflict over polyandry, where male genital features function to manipulate female mating frequency against her interest. Correlated genital evolution across animal groups is consistent with this view, but a link between genital complexity and mating rates remains to be established. In sexually size dimorphic spiders, golden orbweaving spiders (Nephilidae) males mutilate their genitals to form genital plugs, but these plugs do not always prevent female polyandry. In a comparative framework, we test whether male and female genital complexity coevolve, and how these morphologies, as well as sexual cannibalism, relate to the evolution of mating systems. Results Using a combination of comparative tests, we show that male genital complexity negatively correlates with female mating rates, and that levels of sexual cannibalism negatively correlate with male mating rates. We also confirm a positive correlation between male and female genital complexity. The macroevolutionary trajectory is consistent with a repeated evolution from polyandry to monandry coinciding with the evolution towards more complex male genitals. Conclusions These results are consistent with the predictions from sexual conflict theory, although sexual conflict may not be the only mechanism responsible for the evolution of genital complexity and mating systems. Nevertheless, our comparative evidence suggests that in golden orbweavers, male genital complexity limits female mating rates, and sexual cannibalism by females coincides with monogyny. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0821-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Matjaž Kuntner
- Institute of Biology, Research Centre of the Slovenian Academy of Sciences and Arts, Ljubljana, Slovenia. .,National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
| | - Ren-Chung Cheng
- Institute of Biology, Research Centre of the Slovenian Academy of Sciences and Arts, Ljubljana, Slovenia
| | - Simona Kralj-Fišer
- Institute of Biology, Research Centre of the Slovenian Academy of Sciences and Arts, Ljubljana, Slovenia
| | - Chen-Pan Liao
- Department of Life Science, Tunghai University, Taichung, Taiwan
| | - Jutta M Schneider
- Zoological Institute, Biozentrum Grindel, University of Hamburg, Hamburg, Germany
| | - Mark A Elgar
- School of BioSciences, University of Melbourne, Victoria, 3010, Australia
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Neumann R, Schneider JM. Socially cued developmental plasticity in web-building spiders. BMC Evol Biol 2016; 16:170. [PMID: 27561330 PMCID: PMC5000426 DOI: 10.1186/s12862-016-0736-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 08/08/2016] [Indexed: 01/16/2023] Open
Abstract
Background Socially cued anticipatory plasticity (SCAP) has been proposed as a widespread mechanism of adaptive life-history shifts in semelparous species with extreme male mating investment. Such mating systems evolved several times independently in spiders and male reproductive success should critically depend on timely maturation and rapid location of a receptive and, ideally, virgin female. We experimentally investigated socially cued anticipatory plasticity in two sympatric, closely related Nephila species that share many components of their mating systems, but differ in the degree to which male reproductive success depends on mating with virgin females. Juveniles of both species were reared either in the presence or absence of virgin female silk cues. We predicted strong selection on socially cued plasticity in N. fenestrata in which males follow a highly specialized terminal investment strategy, but expected a weaker plastic response in N. senegalensis in which males lost the ability to monopolize females. Results Contrary to our predictions, N. fenestrata males presented with virgin female silk cues did not mature earlier than siblings reared isolated from such cues. Males in N. senegalensis, however, showed a significant response to female cues and matured several days earlier than control males. Plastic adjustment of maturation had no effect on male size. Conclusions Our results indicate that a strong benefit of mating with virgins due to first male sperm priority does not necessarily promote socially cued anticipatory plasticity. We emphasize the bidirectional mode of developmental responses and suggest that this form of plasticity may not only yield benefits through accelerated maturation, but also by avoiding costs of precipitate maturation in the absence of female cues.
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Affiliation(s)
- Rainer Neumann
- Zoologisches Institut, Universität Hamburg, Martin-Luther-King-Platz 3, 20146, Hamburg, Germany.
| | - Jutta M Schneider
- Zoologisches Institut, Universität Hamburg, Martin-Luther-King-Platz 3, 20146, Hamburg, Germany
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Preik OA, Schneider JM, Uhl G, Michalik P. Transition from monogyny to polygyny inNephila senegalensis(Araneae: Nephilidae) is not accompanied by increased investment in sperm. Biol J Linn Soc Lond 2016. [DOI: 10.1111/bij.12863] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Onno A. Preik
- University of Hamburg; Biozentrum Grindel; Zoological Institute; Martin-Luther-King-Platz 3 D-20146 Hamburg Germany
| | - Jutta M. Schneider
- University of Hamburg; Biozentrum Grindel; Zoological Institute; Martin-Luther-King-Platz 3 D-20146 Hamburg Germany
| | - Gabriele Uhl
- University of Greifswald; Zoological Institute and Museum; General and Systematic Zoology; J.S.-Bach Straße 11-12 D-17489 Greifswald Germany
| | - Peter Michalik
- University of Greifswald; Zoological Institute and Museum; General and Systematic Zoology; J.S.-Bach Straße 11-12 D-17489 Greifswald Germany
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Fritzsche K, Timmermeyer N, Wolter M, Michiels NK. Female, but not male, nematodes evolve under experimental sexual coevolution. Proc Biol Sci 2015; 281:20140942. [PMID: 25339719 DOI: 10.1098/rspb.2014.0942] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Coevolution between the sexes is often considered to be male-driven: the male genome is constantly scanned by selection for traits that increase relative male fertilization success. Whenever these traits are harmful to females, the female genome is scanned for resistance traits. The resulting antagonistic coevolution between the sexes is analogous to Red Queen dynamics, where adaptation and counteradaptation keep each other in check. However, the underlying assumption that male trait evolution precedes female trait counteradaptation has received few empirical tests. Using the gonochoristic nematode Caenorhabditis remanei, we now show that 20 generations of relaxed versus increased sexual selection pressure lead to female, but not to male, trait evolution, questioning the generality of a male-driven process.
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Affiliation(s)
- K Fritzsche
- Department of Animal Evolutionary Ecology, Institute for Evolution and Ecology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
| | - N Timmermeyer
- Department of Animal Evolutionary Ecology, Institute for Evolution and Ecology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
| | - M Wolter
- Department of Animal Evolutionary Ecology, Institute for Evolution and Ecology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
| | - N K Michiels
- Department of Animal Evolutionary Ecology, Institute for Evolution and Ecology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
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Ceballos L, Jones TM, Elgar MA. Patterns of Sperm Transfer in the Golden Orb-WeaverNephila edulis. Ethology 2015. [DOI: 10.1111/eth.12375] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Leonor Ceballos
- School of BioSciences; University of Melbourne; Melbourne Vic. Australia
- Departamento de Biología Comparada; Facultad de Ciencias; Universidad Nacional Autónoma de México; México Mexico
| | - Therésa M. Jones
- School of BioSciences; University of Melbourne; Melbourne Vic. Australia
| | - Mark A. Elgar
- School of BioSciences; University of Melbourne; Melbourne Vic. Australia
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Neumann R, Schneider JM. Differential investment and size-related mating strategies facilitate extreme size variation in contesting male spiders. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2014.12.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Sentenská L, Pekár S, Lipke E, Michalik P, Uhl G. Female control of mate plugging in a female-cannibalistic spider (Micaria sociabilis). BMC Evol Biol 2015; 15:18. [PMID: 25886749 PMCID: PMC4327802 DOI: 10.1186/s12862-014-0278-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 12/22/2014] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Sperm competition imposes a strong selective pressure on males, leading to the evolution of various physiological, morphological and behavioral traits. Sperm competition can be prevented by blocking or impeding the access to female genitalia by means of a mating plug. We investigated the factors responsible for plug production and function in the promiscuous female-cannibalistic spider Micaria sociabilis (Gnaphosidae). RESULTS We performed mating trials using females with and without a plug that consists of an amorphous mass. The mating trials demonstrated that the probability of male plugging increased non-linearly with the duration of copulation. Copulation duration and plug production seem to be controlled by the female. We found that females terminated matings later if males were fast at genital coupling. Whereas incomplete plugs had disappeared on the day following copulation, complete plugs persisted (40%). In matings with females with complete plugs, only a small proportion of males (7%) were able to remove the plug, indicating the high effectiveness of plugging. Moreover, males ceased attempts to copulate with plugged females with higher probability. 3D X-ray microscopy of the female and male genitalia showed that the plug material can extend far into the female genital tract and that the plug material is produced by a massive gland inside the palpal organ of the modified male pedipalps. CONCLUSIONS Our study demonstrates that the mating plug in M. sociabilis constitutes an effective male strategy to avoid sperm competition that seems to be under female control.
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Affiliation(s)
- Lenka Sentenská
- Department of Botany and Zoology, Masaryk University, Brno, Czech Republic.
| | - Stano Pekár
- Department of Botany and Zoology, Masaryk University, Brno, Czech Republic.
| | - Elisabeth Lipke
- Department of General and Systematic Zoology, Zoological Institute and Museum, Ernst Moritz Arndt University of Greifswald, Greifswald, Germany.
| | - Peter Michalik
- Department of General and Systematic Zoology, Zoological Institute and Museum, Ernst Moritz Arndt University of Greifswald, Greifswald, Germany.
| | - Gabriele Uhl
- Department of General and Systematic Zoology, Zoological Institute and Museum, Ernst Moritz Arndt University of Greifswald, Greifswald, Germany.
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Kuntner M, Agnarsson I, Li D. The eunuch phenomenon: adaptive evolution of genital emasculation in sexually dimorphic spiders. Biol Rev Camb Philos Soc 2014; 90:279-96. [PMID: 24809822 DOI: 10.1111/brv.12109] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 03/24/2014] [Accepted: 04/01/2014] [Indexed: 12/01/2022]
Abstract
Under natural and sexual selection traits often evolve that secure paternity or maternity through self-sacrifice to predators, rivals, offspring, or partners. Emasculation-males removing their genitals-is an unusual example of such behaviours. Known only in insects and spiders, the phenomenon's adaptiveness is difficult to explain, yet its repeated origins and association with sexual size dimorphism (SSD) and sexual cannibalism suggest an adaptive significance. In spiders, emasculation of paired male sperm-transferring organs - secondary genitals - (hereafter, palps), results in 'eunuchs'. This behaviour has been hypothesized to be adaptive because (i) males plug female genitals with their severed palps (plugging hypothesis), (ii) males remove their palps to become better fighters in male-male contests (better-fighter hypothesis), perhaps reaching higher agility due to reduced total body mass (gloves-off hypothesis), and (iii) males achieve prolonged sperm transfer through severed genitals (remote-copulation hypothesis). Prior research has provided evidence in support of these hypotheses in some orb-weaving spiders but these explanations are far from general. Seeking broad macroevolutionary patterns of spider emasculation, we review the known occurrences, weigh the evidence in support of the hypotheses in each known case, and redefine more precisely the particular cases of emasculation depending on its timing in relation to maturation and mating: 'pre-maturation', 'mating', and 'post-mating'. We use a genus-level spider phylogeny to explore emasculation evolution and to investigate potential evolutionary linkage between emasculation, SSD, lesser genital damage (embolic breakage), and sexual cannibalism (females consuming their mates). We find a complex pattern of spider emasculation evolution, all cases confined to Araneoidea: emasculation evolved at least five and up to 11 times, was lost at least four times, and became further modified at least once. We also find emasculation, as well as lesser genital damage and sexual cannibalism, to be significantly associated with SSD. These behavioural and morphological traits thus likely co-evolve in spiders. Emasculation can be seen as an extreme form of genital mutilation, or even a terminal investment strategy linked to the evolution of monogyny. However, as different emasculation cases in araneoid spiders are neither homologous nor biologically identical, and may or may not serve as paternity protection, the direct link to monogyny is not clear cut. Understanding better the phylogenetic patterns of emasculation and its constituent morphologies and behaviours, a clearer picture of the intricate interplay of natural and sexual selection may arise. With the here improved evolutionary resolution of spider eunuch behaviour, we can more specifically tie the evidence from adaptive hypotheses to independent cases, and propose promising avenues for further research of spider eunuchs, and of the evolution of monogyny.
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Affiliation(s)
- Matjaž Kuntner
- Institute of Biology, Scientific Research Centre, Slovenian Academy of Sciences and Arts, Novi Trg 2, 1000, Ljubljana, Slovenia; Centre for Behavioural Ecology & Evolution, College of Life Sciences, Hubei University, 368 Youyi Road, 430062, Wuhan, China; National Museum of Natural History, Smithsonian Institution, PO Box 37012, Washington, DC, 20013-7012, U.S.A
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Zimmer SM, Schneider JM, Herberstein ME. Can males detect the strength of sperm competition and presence of genital plugs during mate choice? Behav Ecol 2014. [DOI: 10.1093/beheco/aru045] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Fromhage L, Schneider JM. A mate to die for? A model of conditional monogyny in cannibalistic spiders. Ecol Evol 2012; 2:2577-87. [PMID: 23145342 PMCID: PMC3492783 DOI: 10.1002/ece3.372] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 08/08/2012] [Accepted: 08/08/2012] [Indexed: 11/16/2022] Open
Abstract
Monogynous males in various species actively limit themselves to mating with a single female in their lifetime. Whereas previous models have considered monogyny as an obligate mating strategy, here we explore the potential of monogyny to evolve as a context-specific (conditional) behavior. Using a state-dependent dynamic game model based on the biology of the cannibalistic spider Argiope bruennichi, we confirm that conditional monogyny can evolve under broad conditions, including an even sex ratio. We predict that males should make a terminal investment when mating with large, virgin females, especially if population density is low and the encounter occurs late in the season. We encourage empirical tests for the existence of conditional monogyny in all species where monogyny occurs in the absence of strict morphological constraints that would make it obligatory.
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Affiliation(s)
- Lutz Fromhage
- Department of Biological and Environmental Sciences, University of Jyväskylä P.O. Box 35, 40014, Jyväskylä, Finland
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Kuntner M, Gregorič M, Zhang S, Kralj-Fišer S, Li D. Mating plugs in polyandrous giants: which sex produces them, when, how and why? PLoS One 2012; 7:e40939. [PMID: 22829900 PMCID: PMC3400571 DOI: 10.1371/journal.pone.0040939] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 06/15/2012] [Indexed: 12/04/2022] Open
Abstract
Background Males usually produce mating plugs to reduce sperm competition. However, females can conceivably also produce mating plugs in order to prevent unwanted, superfluous and energetically costly matings. In spiders–appropriate models for testing plugging biology hypotheses–mating plugs may consist of male genital parts and/or of amorphous covers consisting of glandular or sperm secretions. In the giant wood spider Nephila pilipes, a highly sexually dimorphic and polygamous species, males are known to produce ineffective embolic plugs through genital damage, but nothing is known about the origin and function of additional conspicuous amorphous plugs (AP) covering female genitals. Methodology We tested alternative hypotheses of the nature and function of AP in N. pilipes by staging mating trials with varying degrees of polyandry. No APs were ever formed during mating trials, which rules out the possibility of male AP formation. Instead, those females that oviposited produced the AP from a liquid secreted during egg sac formation. Polyandrous females were more likely to lay eggs and to produce the AP, as were those that mated longer and with more total insertions. Our further tests revealed that, in spite of being a side product of egg sac production, AP, when hardened, prevented any subsequent copulation. Conclusions We conclude that in the giant wood spider (Nephila pilipes), the amorphous mating plugs are not produced by the males, that repeated copulations (most likely polyandrous) are necessary for egg fertilization and AP formation, and that the AP represents a female adaptation to sexual conflict through prevention of unwanted, excessive copulations. Considering the largely unknown origin of amorphous plugs in spiders, we predict that a similar pattern might be detected in other clades, which would help elucidate the evolutionary interplay of various selection pressures responsible for the origin and maintenance of mating plugs.
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Affiliation(s)
- Matjaž Kuntner
- Institute of Biology, Scientific Research Centre, Slovenian Academy of Sciences and Arts, Ljubljana, Slovenia.
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Eunuchs as better fighters? Naturwissenschaften 2011; 99:95-101. [PMID: 22167072 DOI: 10.1007/s00114-011-0873-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 11/27/2011] [Accepted: 11/30/2011] [Indexed: 10/14/2022]
Abstract
Male-male competition for females can significantly affect a male's reproductive success and hence his fitness. Game theory predicts that an individual should avoid fighting when its future reproductive potential is high, but should fight forcefully when its future reproductive potential is insignificant. When mates are scarce, extreme competition and fatal fighting is expected. We recently showed that Nephilengys malabarensis eunuchs, i.e. sterile spider males that lost their genitals during copulation, become more aggressive during male-male contests. Here, we add crucial comparative data by exploring eunuch fighting behaviour in Nephilengys livida from Madagascar, specifically by testing the 'better fighter hypotheses' in a laboratory setting. Similar to N. malabarensis, N. livida copulations resulted in total male castration with the severed palp plugging the female genitals in 70.83% cases, which mostly (63.63%) prevented subsequent copulations. Unexpectedly, however, N. livida eunuchs exhibited lower aggressiveness than virgin males. We interpret these results in the light of different mating biology between the so far studied species known for the eunuch phenomenon, which might reflect differing plug effectiveness due to variation in genital anatomy in N. livida, N. malabarensis and Herennia multipuncta. However, detected differences in aggressive behaviour of N. livida versus N. malabarensis eunuchs might also be explained by the species' ecology, with lower population densities resulting in a relaxed male-male competition making excessive aggression and mate guarding redundant. This study thus questions the generality of overt aggressiveness in mated males with no reproductive value, and highlights the importance of understanding the natural history of species in the question.
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Mate quality, not aggressive spillover, explains sexual cannibalism in a size-dimorphic spider. Behav Ecol Sociobiol 2011. [DOI: 10.1007/s00265-011-1262-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Rittschof CC, Hilber SA, Tudor MS, St Mary CM. Modeling male reproductive strategies and optimal mate number in an orb-web spider. Behav Ecol 2011. [DOI: 10.1093/beheco/arr142] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Mutual adaptation between mouse transglutaminase 4 and its native substrates in the formation of copulatory plug. Amino Acids 2011; 42:951-60. [DOI: 10.1007/s00726-011-1009-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Accepted: 06/02/2011] [Indexed: 12/16/2022]
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Schneider JM, Michalik P. One-shot genitalia are not an evolutionary dead end - regained male polygamy in a sperm limited spider species. BMC Evol Biol 2011; 11:197. [PMID: 21740561 PMCID: PMC3145602 DOI: 10.1186/1471-2148-11-197] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 07/08/2011] [Indexed: 11/24/2022] Open
Abstract
Background Monogynous mating systems with extremely low male mating rates have several independent evolutionary origins and are associated with drastic adaptations involving self-sacrifice, one-shot genitalia, genital damage, and termination of spermatogenesis immediately after maturation. The combination of such extreme traits likely restricts evolutionary potential perhaps up to the point of making low male mating rates irreversible and hence may constitute an evolutionary dead end. Here, we explore the case of a reversion to multiple mating from monogynous ancestry in golden orb-web spiders, Nephila senegalensis. Results Male multiple mating is regained by the loss of genital damage and sexual cannibalism but spermatogenesis is terminated with maturation, restricting males to a single loading of their secondary mating organs and a fixed supply of sperm. However, males re-use their mating organs and by experimentally mating males to many females, we show that the sperm supply is divided between copulations without reloading the pedipalps. Conclusion By portioning their precious sperm supply, males achieve an average mating rate of four females which effectively doubles the maximal mating rate of their ancestors. A heritage of one-shot genitalia does not completely restrict the potential to increase mating rates in Nephila although an upper limit is defined by the available sperm load. Future studies should now investigate how males use this potential in the field and identify selection pressures responsible for a reversal from monogynous to polygynous mating strategies.
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Affiliation(s)
- Jutta M Schneider
- Biozentrum Grindel, Zoological Institute and Museum, University of Hamburg, Martin-Luther-King Platz 3, D-20146 Hamburg, Germany.
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Pasquet A, Anotaux M, Leborgne R. Loss of legs: is it or not a handicap for an orb-weaving spider? Naturwissenschaften 2011; 98:557-64. [PMID: 21533554 DOI: 10.1007/s00114-011-0799-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 04/07/2011] [Accepted: 04/08/2011] [Indexed: 11/26/2022]
Abstract
Leg loss is a common phenomenon in spiders, and according to the species 5% to 40% of the adults can present at least one missing leg. There is no possibility of regeneration after adult moult and the animal must manage with its missing appendages until its death. With the loss of one or more legs, female orb-weaving spiders can be penalized twice: firstly, because the legs are necessary for web construction and secondly, the legs are essential for the control of the prey after its interception by the web. During development, spiders may be also penalized because regeneration has energetic costs that take away resources for survival, growth and reproduction. All these consequences should influence negatively the development of the spider and thus its fitness. We investigated the impact of leg loss in the orb-weaving spider, Zygiella x-notata by studying its frequency in a natural population and web building and prey capture behaviours in laboratory. In field populations, 9.5% to 13%, of the adult females presented the loss of one or more legs; the majority of individuals had lost only one leg (in 48% of cases, a first one). Leg loss seems to affect all the adult spiders, as there is no difference of mass between intact spiders and those with missing leg. Data obtained with laboratory-reared spiders, showed that the loss of legs due to the moult is rare (less than 1%). Considering changes in web design, spiders with missing legs decreased their silk investment, increased the distance between spiral turns but did not change the capture surface of the web. Under our laboratory experimental conditions, spiders with one or two lost legs did not present any difference in prey capture efficiency. In laboratory conditions, spiders with lost leg(s) did not show any difference in egg sac production or in longevity (adult lifespan) compared to intact spiders.
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Michalik P, Rittschof CC. A comparative analysis of the morphology and evolution of permanent sperm depletion in spiders. PLoS One 2011; 6:e16014. [PMID: 21264312 PMCID: PMC3019211 DOI: 10.1371/journal.pone.0016014] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2010] [Accepted: 12/02/2010] [Indexed: 11/18/2022] Open
Abstract
Once thought to be energetically cheap and easy to produce, empirical work has shown that sperm is a costly and limited resource for males. In some spider species, there is behavioral evidence that sperm are permanently depleted after a single mating. This extreme degree of mating investment appears to co-occur with other reproductive strategies common to spiders, e.g. genital mutilation and sexual cannibalism. Here we corroborate that sperm depletion in the golden orb-web spider Nephila clavipes is permanent by uncovering its mechanistic basis using light and electron microscopy. In addition, we use a phylogeny-based statistical analysis to test the evolutionary relationships between permanent sperm depletion (PSD) and other reproductive strategies in spiders. Male testes do not produce sperm during adulthood, which is unusual in spiders. Instead, spermatogenesis is nearly synchronous and ends before the maturation molt. Testis size decreases as males approach their maturation molt and reaches its lowest point after sperm is transferred into the male copulatory organs (pedipalps). As a consequence, the amount of sperm available to males for mating is limited to the sperm contained in the pedipalps, and once it is used, males lose their ability to fertilize eggs. Our data suggest that PSD has evolved independently at least three times within web-building spiders and is significantly correlated with the evolution of other mating strategies that limit males to monogamy, including genital mutilation and sexual cannibalism. We conclude that PSD may be an energy-saving adaptation in species where males are limited to monogamy. This could be particularly important in web-building spiders where extreme sexual size dimorphism results in large, sedentary females and small, searching males who rarely feed as adults and are vulnerable to starvation. Future work will explore possible energetic benefits and the evolutionary lability of PSD relative to other mate-limiting reproductive behaviors.
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Affiliation(s)
- Peter Michalik
- Zoologisches Institut und Museum, Ernst-Moritz-Arndt-Universität, Greifswald, Germany.
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Althaus S, Jacob A, Graber W, Hofer D, Nentwig W, Kropf C. A double role of sperm in scorpions: the mating plug of Euscorpius italicus (Scorpiones: Euscorpiidae) consists of sperm. J Morphol 2010; 271:383-93. [PMID: 20101728 DOI: 10.1002/jmor.10804] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Mating plugs occluding the female gonopore after mating are a widespread phenomenon. In scorpions, two main types of mating plugs are found: sclerotized mating plugs being parts of the spermatophore that break off during mating, and gel-like mating plugs being gelatinous fluids that harden in the female genital tract. In this study, the gel-like mating plug of Euscorpius italicus was investigated with respect to its composition, fine structure, and changes over time. Sperm forms the major component of the mating plug, a phenomenon previously unknown in arachnids. Three parts of the mating plug can be distinguished. The part facing the outside of the female (outer part) contains sperm packages containing inactive spermatozoa. In this state, sperm is transferred. In the median part, the sperm packages get uncoiled to single spermatozoa. In the inner part, free sperm is embedded in a large amount of secretions. Fresh mating plugs are soft gelatinous, later they harden from outside toward inside. This process is completed after 3-5 days. Sperm from artificially triggered spermatophores could be activated by immersion in insect Ringer's solution indicating that the fluid condition in the females' genital tract or females' secretions causes sperm activation. Because of the male origin of the mating plug, it has likely evolved under sperm competition or sexual conflict. As females refused to remate irrespective of the presence or absence of a mating plug, females may have changed their mating behavior in the course of evolution from polyandry to monandry.
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Affiliation(s)
- Sarah Althaus
- Institute of Ecology and Evolution, University of Bern, Bernastrasse 15, Bern, Switzerland
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Bretman A, Lawniczak MKN, Boone J, Chapman T. A mating plug protein reduces early female remating in Drosophila melanogaster. JOURNAL OF INSECT PHYSIOLOGY 2010; 56:107-113. [PMID: 19800888 DOI: 10.1016/j.jinsphys.2009.09.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Revised: 09/09/2009] [Accepted: 09/18/2009] [Indexed: 05/28/2023]
Abstract
Mating plugs are formed within the female reproductive tract during mating from male ejaculate constituents or even from male genitalia themselves. Across species, mating plugs have roles in sperm storage and the prevention of female remating. In the fruitfly Drosophila melanogaster, accessory gland proteins such as the sex peptide are known to reduce female remating, however this effect can take some time to establish, hence other ejaculate components must also be involved. We hypothesised a role for the PEBII mating plug protein in the prevention of early female remating. Using RNA interference we produced PEBII knockdown males. We found that these males were significantly less able to prevent female remating in the 4h following mating. The mating plugs produced by PEBII knockdown males also showed lower levels of autofluorescence in the first 10min after the start of mating, suggesting they differed in composition to those of control males. Reduced levels of PEBII had no effect, however, on fecundity, progeny production or egg-adult viability in the first 24 after mating, suggesting there were no short-term effects of PEB II on sperm transfer, storage or use. Our results show that PEBII has a subtle but significant role in the prevention of early female remating.
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Affiliation(s)
- Amanda Bretman
- School of Biological Sciences, University of East Anglia, Norwich, Norfolk NR4 7TJ, UK
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Abstract
The intriguing composition and function of mating plugs formed when mosquites mate provides a new understanding of the reproductive biology of this important pest and a window through which to view evolution in action.
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Kuntner M, Coddington JA. Discovery of the largest orbweaving spider species: the evolution of gigantism in Nephila. PLoS One 2009; 4:e7516. [PMID: 19844575 PMCID: PMC2760137 DOI: 10.1371/journal.pone.0007516] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Accepted: 09/13/2009] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND More than 41,000 spider species are known with about 400-500 added each year, but for some well-known groups, such as the giant golden orbweavers, Nephila, the last valid described species dates from the 19(th) century. Nephila are renowned for being the largest web-spinning spiders, making the largest orb webs, and are model organisms for the study of extreme sexual size dimorphism (SSD) and sexual biology. Here, we report on the discovery of a new, giant Nephila species from Africa and Madagascar, and review size evolution and SSD in Nephilidae. METHODOLOGY We formally describe N. komaci sp. nov., the largest web spinning species known, and place the species in phylogenetic context to reconstruct the evolution of mean size (via squared change parsimony). We then test female and male mean size correlation using phylogenetically independent contrasts, and simulate nephilid body size evolution using Monte Carlo statistics. CONCLUSIONS Nephila females increased in size almost monotonically to establish a mostly African clade of true giants. In contrast, Nephila male size is effectively decoupled and hovers around values roughly one fifth of female size. Although N. komaci females are the largest Nephila yet discovered, the males are also large and thus their SSD is not exceptional.
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Affiliation(s)
- Matjaz Kuntner
- Institute of Biology, Scientific Research Centre of the Slovenian Academy of Sciences and Arts, Ljubljana, Slovenia.
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Uhl G, Nessler SH, Schneider JM. Securing paternity in spiders? A review on occurrence and effects of mating plugs and male genital mutilation. Genetica 2009; 138:75-104. [PMID: 19705286 DOI: 10.1007/s10709-009-9388-5] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Accepted: 07/07/2009] [Indexed: 10/20/2022]
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