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Mao A, Zhang S. Autotomy does not affect the locomotor performance of a scorpion. Integr Zool 2024; 19:336-338. [PMID: 37789595 DOI: 10.1111/1749-4877.12767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Affiliation(s)
- Aijia Mao
- Centre for Behavioral Ecology and Evolution, State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China
| | - Shichang Zhang
- Centre for Behavioral Ecology and Evolution, State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China
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2
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Omelko MM, Marusik YM. Ride on female for "prima nocta" or close attachment in the araneid spider Caerostris sumatrana Strand, 1915 (Araneae: Araneidae). Zootaxa 2023; 5311:281-288. [PMID: 37518643 DOI: 10.11646/zootaxa.5311.2.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Indexed: 08/01/2023]
Abstract
A unique type of mate guarding behavior is discovered in the araneid spider Caerostris sumatrana Strand, 1915: the male waits for the female's maturity while staying tied to the dorsal surface of her abdomen. The species is redescribed in detail. General appearance of the male and its fine structures are illustrated by scanning electron microscopy for the first time. Genital emasculation in the male of this species is reported for the first time.
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Affiliation(s)
- Mikhail M Omelko
- Federal Scientific Center of East Asia Terrestrial Biodiversity; Far Eastern Branch; Russian Academy of Sciences; Vladivostok 690022; Russia. Institute for Biological Problems of the North; Portovaya Street 18; Magadan 685000; Russia..
| | - Yuri M Marusik
- Department of Zoology & Entomology; University of the Free State; Bloemfontein 9300; South Africa. Altai State University; Lenina Pr.; 61; Barnaul; RF-656049; Russia..
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3
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Izquierdo MA, Dederichs TM, Cargnelutti F, Michalik P. Copulatory behaviour and genital mechanics suggest sperm allocation by a non-intromittent sclerite in a pholcid spider. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230263. [PMID: 37266042 PMCID: PMC10230183 DOI: 10.1098/rsos.230263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 05/02/2023] [Indexed: 06/03/2023]
Abstract
The male genitalia of pholcid spiders, which is one of the most species-rich spider families, are characterized by a procursus, which is a morphologically diverse projection of the copulatory organ. It has been shown that the procursus interacts with the female genitalia during copulation. Here, we investigate the function of the procursus in Gertschiola neuquena, a species belonging to the early branched and understudied subfamily Ninetinae, using behavioural and morphological data. Although many aspects of the copulatory behaviour of G. neuquena follow the general pattern described for the family, males use only one pedipalp during each copulation. Based on our micro-CT analysis of cryofixed mating pairs using virgin females, we can show that the long and filiform procursus is inserted deeply into the unpaired convoluted female spermatheca, and the intromittent sclerite, the embolus, is rather short and stout only reaching the most distal part of the female sperm storage organ. Histological data revealed that sperm are present in the most proximal part of the spermatheca, suggesting that the procursus is used to allocate sperm deeply into the female sperm storage organ. This represents the first case of a replacement of the sperm allocation function of the intromittent sclerite in spiders.
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Affiliation(s)
- M. A. Izquierdo
- Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Diversidad Biológica y Ecología, Universidad Nacional de Córdoba, Córdoba, 5000, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Laboratorio de Biología Reproductiva y Evolución, Instituto de Diversidad y Ecología Animal (IDEA), Córdoba, 5000, Argentina
| | - T. M. Dederichs
- Universität Greifswald, Zoologisches Institut und Museum, Loitzer Straße 26, 17489 Greifswald, Germany
| | - F. Cargnelutti
- Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Diversidad Biológica y Ecología, Universidad Nacional de Córdoba, Córdoba, 5000, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Laboratorio de Biología Reproductiva y Evolución, Instituto de Diversidad y Ecología Animal (IDEA), Córdoba, 5000, Argentina
| | - P. Michalik
- Universität Greifswald, Zoologisches Institut und Museum, Loitzer Straße 26, 17489 Greifswald, Germany
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4
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Ma N, Gong D, Mao A, Zhao Y, Jiao X, Liu J, Peng Y, Zhang S, Peng Y, Zhang S. Traumatic mating causes strict monandry in a wolf spider. Zool Res 2023; 44:101-104. [PMID: 36419377 PMCID: PMC9841190 DOI: 10.24272/j.issn.2095-8137.2022.336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Nina Ma
- State Key Laboratory of Biocatalysis and Enzyme Engineering & Centre for Behavioural Ecology & Evolution, School of Life Sciences, Hubei University, Wuhan, Hubei 430062, China
| | - Deyong Gong
- State Key Laboratory of Biocatalysis and Enzyme Engineering & Centre for Behavioural Ecology & Evolution, School of Life Sciences, Hubei University, Wuhan, Hubei 430062, China
| | - Aijia Mao
- State Key Laboratory of Biocatalysis and Enzyme Engineering & Centre for Behavioural Ecology & Evolution, School of Life Sciences, Hubei University, Wuhan, Hubei 430062, China
| | - Yao Zhao
- State Key Laboratory of Biocatalysis and Enzyme Engineering & Centre for Behavioural Ecology & Evolution, School of Life Sciences, Hubei University, Wuhan, Hubei 430062, China
| | - Xiaoguo Jiao
- State Key Laboratory of Biocatalysis and Enzyme Engineering & Centre for Behavioural Ecology & Evolution, School of Life Sciences, Hubei University, Wuhan, Hubei 430062, China
| | - Jie Liu
- Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Science, Hubei University, Wuhan, Hubei 430062, China
| | - Yu Peng
- Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Science, Hubei University, Wuhan, Hubei 430062, China
| | - Shichang Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering & Centre for Behavioural Ecology & Evolution, School of Life Sciences, Hubei University, Wuhan, Hubei 430062, China,
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5
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Male mating strategies to counter sexual conflict in spiders. Commun Biol 2022; 5:534. [PMID: 35655093 PMCID: PMC9163124 DOI: 10.1038/s42003-022-03512-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 05/20/2022] [Indexed: 12/04/2022] Open
Abstract
When sexual conflict selects for reproductive strategies that only benefit one of the sexes, evolutionary arms races may ensue. Female sexual cannibalism is an extreme manifestation of sexual conflict. Here we test two male mating strategies aiming at countering sexual cannibalism in spiders. The “better charged palp” hypothesis predicts male selected use of the paired sexual organ (palp) containing more sperm for their first copulation. The “fast sperm transfer” hypothesis predicts accelerated insemination when cannibalism is high. Our comparative tests on five orbweb spider species with varying levels of female sexual cannibalism and sexual size dimorphism (SSD) reveal that males choose the palp with more sperm for the first copulation with cannibalistic females and that males transfer significantly more sperm if females are cannibalistic or when SSD is biased. By supporting the two hypotheses, these results provide credibility for male mating syndrome. They, however, open new questions, namely, how does a male differentiate sperm quantities between his palps? How does he perform palp choice after assessing his cannibalistic partner? By conducting follow-up experiments on Nephilengys malabarensis, we reveal that it is sperm volume detection, rather than left-right palp dominance, that plays prominently in male palp choice. Male spiders make choices about how to maximise their mating success when at risk of cannibalisation by females.
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6
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Yu KP, Kuntner M, Cheng RC. Phylogenetic evidence for an independent origin of extreme sexual size dimorphism in a genus of araneid spiders (Araneae: Araneidae). INVERTEBR SYST 2022. [DOI: 10.1071/is21019] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Cyphalonotus is a poorly studied Old World araneid spider genus of which the phylogenetic proximity remains unknown due to the paucity of morphological and molecular data. We test the phylogenetic placement and the taxonomic composition of Cyphalonotus and place the male and female size variation of Cyphalonotus and related genera in an evolutionary context. Our collection and field observations from Taiwan and China facilitate description of a new and a known species, and original sequence data enable species delimitation and phylogenetic analyses. The phylogenetic results reject all four classification hypotheses from the literature and instead recover a well-supported clade comprising Cyphalonotus + Poltys. We review the male and female size variation in Cyphalonotus, Poltys and related genera. These data reveal that all known species of Poltys are extremely sexually size dimorphic (eSSD = females over twice the size of males) reaching values exceeding 10-fold differences, whereas Cyphalonotus and other genera in phylogenetic proximity are relatively sexually monomorphic (SSD < 2.0). This confirms an independent origin of eSSD in Poltys, one of multiple convergent evolutionary outcomes in orbweb spiders.
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7
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Ma Y, Hua Z, Mao A, Li D, Zhang S. Male opportunistic mating increases with intensity of female sexual cannibalism in three web-building spiders. Curr Zool 2021; 68:113-119. [PMID: 35169634 PMCID: PMC8836337 DOI: 10.1093/cz/zoab090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 10/26/2021] [Indexed: 11/13/2022] Open
Abstract
Sexual conflict is common in animals, and female sexual cannibalism represents an extreme form of sexual conflict. Males in many species have evolved a variety of strategies to circumvent or decrease the risk of female sexual cannibalism. Opportunistic mating, by which a male mates with a female when she is disturbed or when she is feeding or undertaking moulting, is one of such kinds of strategies, and widely occurs in many animals, especially in spiders. However, whether the occurrence of male opportunistic mating depends on the intensity of female sexual cannibalism remains largely unexplored. We predicted a positive correlation between them. In this study, we tested this prediction by performing a series of mating trials in the laboratory using 3 species of web-building spiders with different intensities of female sexual cannibalism: Nephila pilipes, Nephilengys malabarensis, and Parasteatoda tepidariorum. We found that the occurrence of male opportunistic mating was positively, though not statistically significantly, correlated with the intensity of female sexual cannibalism, thus supporting our hypothesis. All together, we provide evidence that male opportunistic mating may have evolved to respond to the selection pressure posed by female sexual cannibalism.
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Affiliation(s)
- Yubing Ma
- State Key Laboratory of Biocatalysis and Enzyme Engineering of China & Centre for Behavioral Ecology & Evolution, School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Zeyuan Hua
- State Key Laboratory of Biocatalysis and Enzyme Engineering of China & Centre for Behavioral Ecology & Evolution, School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Aijia Mao
- State Key Laboratory of Biocatalysis and Enzyme Engineering of China & Centre for Behavioral Ecology & Evolution, School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Daiqin Li
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Singapore
| | - Shichang Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering of China & Centre for Behavioral Ecology & Evolution, School of Life Sciences, Hubei University, Wuhan, 430062, China
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8
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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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9
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Machine learning approaches identify male body size as the most accurate predictor of species richness. BMC Biol 2020; 18:105. [PMID: 32854698 PMCID: PMC7453550 DOI: 10.1186/s12915-020-00835-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 07/22/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A major challenge in biodiversity science is to understand the factors contributing to the variability of species richness -the number of different species in a community or region - among comparable taxonomic lineages. Multiple biotic and abiotic factors have been hypothesized to have an effect on species richness and have been used as its predictors, but identifying accurate predictors is not straightforward. Spiders are a highly diverse group, with some 48,000 species in 120 families; yet nearly 75% of all species are found within just the ten most speciose families. Here we use a Random Forest machine learning algorithm to test the predictive power of different variables hypothesized to affect species richness of spider genera. RESULTS We test the predictive power of 22 variables from spiders' morphological, genetic, geographic, ecological and behavioral landscapes on species richness of 45 genera selected to represent the phylogenetic and biological breath of Araneae. Among the variables, Random Forest analyses find body size (specifically, minimum male body size) to best predict species richness. Multiple Correspondence analysis confirms this outcome through a negative relationship between male body size and species richness. Multiple Correspondence analyses furthermore establish that geographic distribution of congeneric species is positively associated with genus diversity, and that genera from phylogenetically older lineages are species poorer. Of the spider-specific traits, neither the presence of ballooning behavior, nor sexual size dimorphism, can predict species richness. CONCLUSIONS We show that machine learning analyses can be used in deciphering the factors associated with diversity patterns. Since no spider-specific biology could predict species richness, but the biologically universal body size did, we believe these conclusions are worthy of broader biological testing. Future work on other groups of organisms will establish whether the detected associations of species richness with small body size and wide geographic ranges hold more broadly.
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10
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Kuntner M, Coddington JA. Sexual Size Dimorphism: Evolution and Perils of Extreme Phenotypes in Spiders. ANNUAL REVIEW OF ENTOMOLOGY 2020; 65:57-80. [PMID: 31573828 DOI: 10.1146/annurev-ento-011019-025032] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Sexual size dimorphism is one of the most striking animal traits, and among terrestrial animals, it is most extreme in certain spider lineages. The most extreme sexual size dimorphism (eSSD) is female biased. eSSD itself is probably an epiphenomenon of gendered evolutionary drivers whose strengths and directions are diverse. We demonstrate that eSSD spider clades are aberrant by sampling randomly across all spiders to establish overall averages for female (6.9 mm) and male (5.6 mm) size. At least 16 spider eSSD clades exist. We explore why the literature does not converge on an overall explanation for eSSD and propose an equilibrium model featuring clade- and context-specific drivers of gender size variation. eSSD affects other traits such as sexual cannibalism, genital damage, emasculation, and monogyny with terminal investment. Coevolution with these extreme sexual phenotypes is termed eSSD mating syndrome. Finally, as costs of female gigantism increase with size, eSSD may represent an evolutionary dead end.
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Affiliation(s)
- Matjaž Kuntner
- Evolutionary Zoology Laboratory, Department of Organisms and Ecosystems Research, National Institute of Biology, SI-1000 Ljubljana, Slovenia;
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560-0105, USA;
- Evolutionary Zoology Laboratory, Institute of Biology ZRC SAZU, SI-1001 Ljubljana, Slovenia
| | - Jonathan A Coddington
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560-0105, USA;
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11
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Immature mating as a tactic of polygynous male western widow spiders. Naturwissenschaften 2020; 107:6. [DOI: 10.1007/s00114-019-1663-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 12/12/2019] [Accepted: 12/19/2019] [Indexed: 12/24/2022]
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12
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13
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Assis BA, Foellmer MW. Optimal ultra-short copulation duration in a sexually cannibalistic spider. Behav Ecol Sociobiol 2019. [DOI: 10.1007/s00265-019-2733-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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14
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Zhang S, Ai H, Li D. Mating changes a male contestant from a loser to a winner in male–male competition in a wolf spider. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz091] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Mating may change a male’s behaviour by increasing its motivation to engage in a contest, and enabling it to win in subsequent male–male contests. To test this hypothesis, we recorded male contests in the wolf spider, Venonia coruscans (Araneae: Lycosidae), testing a male’s motivation to fight under three different resource value conditions. First, we staged contests between two males in two different resource value conditions, on an egg-produced female’s web and then on a virgin female’s web, to test a male’s fighting ability. After determining each male’s fighting ability, we allowed each loser that lost its contests under both resource value conditions to mate with a virgin female and then introduced the previous contest winner to the web where the loser had mated. We found that without mating, the losers always lost their contests, regardless of the resource value conditions. However, once they had mated, the losers fiercely attacked the previous winners, and most won the contests back. Our study therefore provides evidence that a male’s motivation to fight can be changed under certain circumstances (e.g. mating) and can greatly influence contest outcomes in male–male competition in a mating context.
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Affiliation(s)
- Shichang Zhang
- Centre for Behavioral Ecology and Evolution (CBEE), State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Hui Ai
- College of Life Science, Central China Normal University, Wuhan, Hubei, China
| | - Daiqin Li
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
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15
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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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16
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Kallal RJ, Hormiga G. Systematics, phylogeny and biogeography of the Australasian leaf-curling orb-weaving spiders (Araneae: Araneidae: Zygiellinae), with a comparative analysis of retreat evolution. Zool J Linn Soc 2018. [DOI: 10.1093/zoolinnean/zly014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Robert J Kallal
- The George Washington University, Department of Biological Sciences, Washington, D.C., USA
| | - Gustavo Hormiga
- The George Washington University, Department of Biological Sciences, Washington, D.C., USA
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17
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18
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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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19
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Lupše N, Cheng RC, Kuntner M. Coevolution of female and male genital components to avoid genital size mismatches in sexually dimorphic spiders. BMC Evol Biol 2016; 16:161. [PMID: 27535025 PMCID: PMC4989301 DOI: 10.1186/s12862-016-0734-9] [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: 03/18/2016] [Accepted: 08/05/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In most animal groups, it is unclear how body size variation relates to genital size differences between the sexes. While most morphological features tend to scale with total somatic size, this does not necessarily hold for genitalia because divergent evolution in somatic size between the sexes would cause genital size mismatches. Theory predicts that the interplay of female-biased sexual size dimorphism (SSD) and sexual genital size dimorphism (SGD) should adhere to the 'positive genital divergence', the 'constant genital divergence', or the 'negative genital divergence' model, but these models remain largely untested. We test their validity in the spider family Nephilidae known for the highest degrees of SSD among terrestrial animals. RESULTS Through comparative analyses of sex-specific somatic and genital sizes, we first demonstrate that 99 of the 351 pairs of traits are phylogenetically correlated. Through factor analyses we then group these traits for MCMCglmm analyses that test broader correlation patterns, and these reveal significant correlations in 10 out of the 36 pairwise comparisons. Both types of analyses agree that female somatic and internal genital sizes evolve independently. While sizes of non-intromittent male genital parts coevolve with male body size, the size of the intromittent male genital parts is independent of the male somatic size. Instead, male intromittent genital size coevolves with female (external and, in part, internal) genital size. All analyses also agree that SGD and SSD evolve independently. CONCLUSIONS Internal dimensions of female genitalia evolve independently of female body size in nephilid spiders, and similarly, male intromittent genital size evolves independently of the male body size. The size of the male intromittent organ (the embolus) and the sizes of female internal and external genital components thus seem to respond to selection against genital size mismatches. In accord with these interpretations, we reject the validity of the existing theoretical models of genital and somatic size dimorphism in spiders.
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Affiliation(s)
- Nik Lupše
- Institute of Biology, Research Centre of the Slovenian Academy of Sciences and Arts, Ljubljana, Slovenia
| | - Ren-Chung Cheng
- Institute of Biology, Research Centre of the Slovenian Academy of Sciences and Arts, Ljubljana, Slovenia
| | - Matjaž Kuntner
- Institute of Biology, Research Centre of the Slovenian Academy of Sciences and Arts, Ljubljana, Slovenia. .,Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC, 20013-7012, USA.
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Gregorič M, Šuen K, Cheng RC, Kralj-Fišer S, Kuntner M. Spider behaviors include oral sexual encounters. Sci Rep 2016; 6:25128. [PMID: 27126507 PMCID: PMC4850386 DOI: 10.1038/srep25128] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 04/11/2016] [Indexed: 11/09/2022] Open
Abstract
Several clades of spiders whose females evolved giant sizes are known for extreme sexual behaviors such as sexual cannibalism, opportunistic mating, mate-binding, genital mutilation, plugging, and emasculation. However, these behaviors have only been tested in a handful of size dimorphic spiders. Here, we bring another lineage into the picture by reporting on sexual behavior of Darwin's bark spider, Caerostris darwini. This sexually size dimorphic Madagascan species is known for extreme web gigantism and for producing the world's toughest biomaterial. Our field and laboratory study uncovers a rich sexual repertoire that predictably involves cannibalism, genital mutilation, male preference for teneral females, and emasculation. Surprisingly, C. darwini males engage in oral sexual encounters, rarely reported outside mammals. Irrespective of female's age or mating status males salivate onto female genitalia pre-, during, and post-copulation. While its adaptive significance is elusive, oral sexual contact in spiders may signal male quality or reduce sperm competition.
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Affiliation(s)
- Matjaž Gregorič
- Institute of Biology, Scientific Research Centre of the Slovenian Academy of Sciences and Arts, Slovenia
| | - Klavdija Šuen
- Institute of Biology, Scientific Research Centre of the Slovenian Academy of Sciences and Arts, Slovenia
| | - Ren-Chung Cheng
- Institute of Biology, Scientific Research Centre of the Slovenian Academy of Sciences and Arts, Slovenia
| | - Simona Kralj-Fišer
- Institute of Biology, Scientific Research Centre of the Slovenian Academy of Sciences and Arts, Slovenia
| | - Matjaž Kuntner
- Institute of Biology, Scientific Research Centre of the Slovenian Academy of Sciences and Arts, Slovenia
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
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Assis BA, Foellmer MW. One size fits all? Determinants of sperm transfer in a highly dimorphic orb-web spider. J Evol Biol 2016; 29:1106-20. [DOI: 10.1111/jeb.12848] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 02/02/2016] [Indexed: 11/28/2022]
Affiliation(s)
- B. A. Assis
- Department of Biology; Adelphi University; 1 South Ave. Garden City NY 11530 USA
| | - M. W. Foellmer
- Department of Biology; Adelphi University; 1 South Ave. Garden City NY 11530 USA
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22
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Schneider JM, Zimmer SM, Gatz AL, Sauerland K. Context- and State-Dependent Male Mate Choice in a Sexually Cannibalistic Spider. Ethology 2016. [DOI: 10.1111/eth.12466] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Jutta M. Schneider
- Zoological Institute; Biocenter Grindel; University of Hamburg; Hamburg Germany
| | - Stefanie M. Zimmer
- Zoological Institute; Biocenter Grindel; University of Hamburg; Hamburg Germany
| | - Anna L. Gatz
- Zoological Institute; Biocenter Grindel; University of Hamburg; Hamburg Germany
| | - Kristin Sauerland
- Zoological Institute; Biocenter Grindel; University of Hamburg; Hamburg Germany
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23
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Evolutionary Pathways Maintaining Extreme Female-Biased Sexual Size Dimorphism: Convergent Spider Cases Defy Common Patterns. Evol Biol 2016. [DOI: 10.1007/978-3-319-41324-2_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Mouginot P, Prügel J, Thom U, Steinhoff POM, Kupryjanowicz J, Uhl G. Securing Paternity by Mutilating Female Genitalia in Spiders. Curr Biol 2015; 25:2980-4. [PMID: 26549254 DOI: 10.1016/j.cub.2015.09.074] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 09/16/2015] [Accepted: 09/30/2015] [Indexed: 10/22/2022]
Abstract
Competition between males and their sperm over access to females and their eggs has resulted in manifold ways by which males try to secure paternity, ranging from physically guarding the female after mating to reducing her receptivity or her attractiveness to subsequent males by transferring manipulative substances or by mechanically sealing the female reproductive tract with a copulatory plug. Copulations may also result in internal damage of the female genitalia; however, this is not considered as a direct adaptation against sperm competition but as a collateral effect. Here, we present a drastic and direct mechanism for securing paternity: the removal of coupling structures on female genitalia by males. In the orb-weaving spider Larinia jeskovi males remove the scapus, a crucial coupling device on the female external genital region. Reconstruction of the coupling mechanism using micro-CT-scanned mating pairs revealed that several sclerites of the male genitalia interact to break off the scapus. Once it is removed, remating cannot occur due to mechanical coupling difficulties. In the field, male-inflicted genital damage is very prevalent since all female L. jeskovi were found to be mutilated at the end of the mating season. External genital mutilation is an overlooked but widely spread phenomenon since 80 additional spider species were found for which male genital manipulation can be suspected. Interlocking genitalia provide an evolutionary platform for the rapid evolution of this highly effective mechanism to secure paternity, and we suspect that other animal groups with interlocking genital structures might reveal similarly drastic male adaptations.
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Affiliation(s)
- Pierick Mouginot
- General and Systematic Zoology, Zoological Institute and Museum, University of Greifswald, Greifswald 17489, Germany
| | - Josepha Prügel
- General and Systematic Zoology, Zoological Institute and Museum, University of Greifswald, Greifswald 17489, Germany
| | - Ulrike Thom
- General and Systematic Zoology, Zoological Institute and Museum, University of Greifswald, Greifswald 17489, Germany
| | - Philip O M Steinhoff
- General and Systematic Zoology, Zoological Institute and Museum, University of Greifswald, Greifswald 17489, Germany
| | | | - Gabriele Uhl
- General and Systematic Zoology, Zoological Institute and Museum, University of Greifswald, Greifswald 17489, Germany.
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Cheng RC, Kuntner M. Phylogeny suggests nondirectional and isometric evolution of sexual size dimorphism in argiopine spiders. Evolution 2014; 68:2861-72. [PMID: 25130435 DOI: 10.1111/evo.12504] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 06/15/2014] [Indexed: 11/28/2022]
Abstract
Sexual dimorphism describes substantial differences between male and female phenotypes. In spiders, sexual dimorphism research almost exclusively focuses on size, and recent studies have recovered steady evolutionary size increases in females, and independent evolutionary size changes in males. Their discordance is due to negative allometric size patterns caused by different selection pressures on male and female sizes (converse Rensch's rule). Here, we investigated macroevolutionary patterns of sexual size dimorphism (SSD) in Argiopinae, a global lineage of orb-weaving spiders with varying degrees of SSD. We devised a Bayesian and maximum-likelihood molecular species-level phylogeny, and then used it to reconstruct sex-specific size evolution, to examine general hypotheses and different models of size evolution, to test for sexual size coevolution, and to examine allometric patterns of SSD. Our results, revealing ancestral moderate sizes and SSD, failed to reject the Brownian motion model, which suggests a nondirectional size evolution. Contrary to predictions, male and female sizes were phylogenetically correlated, and SSD evolution was isometric. We interpret these results to question the classical explanations of female-biased SSD via fecundity, gravity, and differential mortality. In argiopines, SSD evolution may be driven by these or additional selection mechanisms, but perhaps at different phylogenetic scales.
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Affiliation(s)
- Ren-Chung Cheng
- Institute of Biology, Scientific Research Centre of the Slovenian Academy of Sciences and Arts, Ljubljana, Slovenia.
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