Sexual conflict over the duration of copulation in <it>Drosophila montana</it>: why is longer better? by Hoikkala Anneli, Kesäniemi Jenni, Mazzi Dominique, Klappert Kirsten

“…We staged matings under different sex ratio conditions, and provide evidence that copulation duration is a form of male reproductive investment that responds to the perceived intensity of sperm competition as predicted by game theoretical models. …”
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High prevalence of multiple paternity in the invasive crayfish species, Procambarus clarkii by Gen Hua Yue, Jia Le Li, Chun Ming Wang, Jun Hong Xia, Gen Lin Wang, Jian Bing Feng

“…Indirect benefits from increasing the genetic diversity of broods, male and sperm competition, and cryptic female choice are a possible explanation for the high level multiple paternity and different contribution of fathers to offspring in this species.…”
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Evaluating the relationship between spermatogenic silencing of the X chromosome and evolution of the Y chromosome in chimpanzee and human. by Eskeatnaf Mulugeta Achame, Willy M Baarends, Joost Gribnau, J Anton Grootegoed

“…Chimpanzees have a highly polygamous mating behavior, so that sperm competition is thought to provide a strong selective force acting on the Y chromosome in the chimpanzee lineage. …”
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Growth and reproduction of Xyrichthys novacula (Pisces: Labridae) in the Mediterranean Sea by M. Cardinale, F. Colloca, G. D. Ardizzone

“…This is probably a consequence of the haremic mating system of the species which reduces sperm competition between males. A new coloration phase for females was introduced in addition to the three already described in the literature. …”
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Mating behavior and sexual selection in a polygamous beetle by Wen LU, Qiao WANG, Mingyi TIAN, Jin XU, Jian LV, Aizhi QIN

“…Longer bursa copulatrix accommodated a larger ejaculate, suggesting that this female trait benefits the male that first mates with the female in terms of increasing ejaculate size to beat subsequent males in sperm competition. Under a female-biased sex ratio, more than 20% of matings failed within 20s after the male genitalia had been inserted into hers, suggesting that males assess genital features of the female before insemination and undertake cryptic male mate choice. …”
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Reproductive success in wild and hatchery male coho salmon by Bryan D. Neff, Shawn R. Garner, Ian A. Fleming, Mart R. Gross

“…This paternity difference may result from inferior performance of hatchery males during sperm competition, female mate choice for wild males, or differential offspring survival. …”
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Sperm dynamics in spiders (Araneae): ultrastructural analysis of the sperm activation process in the garden spider Argiope bruennichi (Scopoli, 1772). by Oliver Vöcking, Gabriele Uhl, Peter Michalik

“…The sperm storage site constitutes the arena for sperm activation, sperm competition and female sperm choice. Consequently, to understand animal mating systems information on the processes that occur from sperm transfer to fertilization is required. …”
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Reproductive consequences of an extra long-term sperm storage organ by Akashdeep Dhillon, Tabashir Chowdhury, Yolanda E. Morbey, Amanda J. Moehring

“…Conclusions Thus, additional long-term sperm storage in insects may increase female fitness through extending the range of conditions where she produces offspring, or through increasing the quality of offspring via enhanced local sperm competition at fertilization.…”
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Sexual selection and hermaphroditic organisms: Testing theory by Janet L. LEONARD

“…Many simultaneous hermaphrodites have elaborate courtship and genital anatomy, suggesting sexual selection plays an important role in reproductive success. Sperm competition and cryptic female choice mean that the number of mates acquired is not necessarily a predictor of reproductive success. …”
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Male fertility in natural populations of red deer is determined by sperm velocity and the proportion of normal spermatozoa. by Malo, A, Garde, J, Soler, A, García, A, Gomendio, M, Roldan, E

“…Among polygynous mammals, males differ markedly in their reproductive success, and a great deal of effort has been made to understand how selective forces have shaped traits that enhance male competitiveness both before and after copulation (i.e., sperm competition). However, the possibility that males also may differ in their fertility has been ignored under the assumption that male infertility is rare in natural populations because selection against it is likely to be strong. …”

Behavioral ecology of Heteragrion consors Hagen (Odonata, Megapodagrionidae): a shade-seek Atlantic forest damselfly by Geovanni Ribeiro Loiola, Paulo De Marco

“…Abdominal movements associated to long lasting copula pointed to the existence of sperm competition in this species. Males performed contact post-copulatory guarding of the females. …”
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Hit or Miss: Fertilization Outcomes of Natural Inseminations by Japanese Quail. by Elizabeth Adkins-Regan

“…Paradoxically, this low and probabilistic fertilization success co-occurs with other notable characteristics of male quail suggestive of past sexual selection for increased success, including vigorous copulatory behavior, forced copulations, foamy secretion aiding in sperm competition, large testes and unusual sperm morphology.…”
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Recent advances in bird sperm morphometric analysis and its role in male gamete characterization and reproduction technologies by Julian Santiago-Moreno, Milagros Cristina Esteso, Silvia Villaverde-Morcillo, Adolfo Toledano-Déaz, Cristina Castaño, Rosario Velázquez, Antonio López-Sebastián, Agustín López Goya, Javier Gimeno Martínez

“…Postcopulatory sexual selection through sperm competition may be an important evolutionary force affecting many reproductive traits, including sperm morphometrics. …”
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Sperm Morphology and Male Age in Black-Throated Blue Warblers, an Ecological Model System by Emily Cramer, Nicole Krauss, Tricia Rowlison, Pierre Comizzoli

“…Extra-pair paternity may drive selection on spermatozoa and ejaculate characteristics through sperm competition and cryptic female choice. Here, we examine sperm morphology in the black-throated blue warbler (<i>Setophaga caerulescens</i>), an ecological model species where extra-pair paternity is frequent and is linked with male age. …”
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Extreme fertilization bias towards freshly inseminated sperm in a species exhibiting prolonged female sperm storage by Clelia Gasparini, Emma Daymond, Jonathan P. Evans

“…This gap in our understanding is likely due to the logistical difficulties of controlling behavioural interactions during or after mating, which in turn may influence how many sperm are inseminated and how stored sperm are ultimately used during successive bouts of sperm competition with freshly inseminated sperm. Here, we use artificial insemination (AI) in guppies (Poecilia reticulata), a polyandrous live-bearing poeciliid fish exhibiting prolonged sperm storage by females, to overcome these challenges. …”
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Viability is associated with melanin-based coloration in the barn swallow (Hirundo rustica). by Nicola Saino, Maria Romano, Diego Rubolini, Roberto Ambrosini, Manuela Caprioli, Aldo Milzani, Alessandra Costanzo, Graziano Colombo, Luca Canova, Kazumasa Wakamatsu

“…We discuss the possibility that eu- and pheomelanization are under contrasting viability and sexual selection, as suggested by larger breeding and sperm competition success of darker males from other barn swallow subspecies.…”
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Weighing costs and benefits of mating in bushcrickets (Insecta: Orthoptera: Tettigoniidae), with an emphasis on nuptial gifts, protandry and mate density by Lehmann Gerlind U C

“…Where males mature before females (protandry) the level of protandry varies in the direction predicted by sperm competition theory; namely, early male maturation is correlated with a high level of first inseminations being reproductively successful. …”
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Selection on space use in a polymorphic lizard by Olsson, M, Wapstra, E, Healey, M, Schwartz, T, Uller, T

“…Question: In the annual Australian painted dragon lizard (Ctenophorus pictus; less than 10% survive to a second year), red males dominate yellow males in staged contests, and yellow males (sneakers) are superior in sperm competition trials. Here, we ask whether there is ongoing disruptive selection for red males to defend well-defined, smaller territories (dominants) and for yellow males to have larger, more loosely defined territories (sneakers). …”

Transcription regulation of sex-biased genes during ontogeny in the malaria vector Anopheles gambiae. by Kalle Magnusson, Antonio M Mendes, Nikolai Windbichler, Philippos-Aris Papathanos, Tony Nolan, Tania Dottorini, Ermanno Rizzi, George K Christophides, Andrea Crisanti

“…This finding is particularly intriguing because A. gambiae is a strictly female monogamous species suggesting that driving forces in addition to sperm competition must account for the rapid evolution of male-biased genes. …”
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Reproductive strategies of Aedes albopictus (Diptera: Culicidae) and implications for the sterile insect technique. by Clelia F Oliva, David Damiens, Marc J B Vreysen, Guy Lemperière, Jérémie Gilles

“…Multiple inseminations and therefore the possibility of sperm competition were limited to matings closely spaced in time. …”
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