Sperm wars and the evolution of male fertility

Reproduction

Volumn 144, Issue 5, 2012, Pages 519-534

  Simmons, Leigh W ^a   Fitzpatrick, John L ^a  

^a UNIVERSITY OF WESTERN AUSTRALIA   (Australia)

Author keywords

[No Author keywords available]

Indexed keywords

SEMINAL PLASMA PROTEIN;

BEETLE; DIPTERA; DROSOPHILA MELANOGASTER; EVOLUTION; FERTILIZATION; MALE FERTILITY; NONHUMAN; ONTHOPHAGUS TAURUS; PRIORITY JOURNAL; REVIEW; SCATHOPAGA STERCORARIA; SPERM COMPETITION; SPERMATOGENESIS; SPERMATOZOON DENSITY; SPERMATOZOON MOTILITY; TESTIS SIZE;

ANIMALS; BIOLOGICAL EVOLUTION; CELL SIZE; COMPETITIVE BEHAVIOR; FEMALE; FERTILITY; FERTILIZATION; HUMANS; MALE; SEMEN; SEMINAL PLASMA PROTEINS; SEXUAL BEHAVIOR; SEXUAL BEHAVIOR, ANIMAL; SPERM MOTILITY; SPERMATOGENESIS; SPERMATOZOA; TESTIS;

EID: 84868350931     PISSN: 14701626     EISSN: 17417899     Source Type: Journal    
DOI: 10.1530/REP-12-0285     Document Type: Review

References (234)

1. Alonzo SH & Pizzari T 2010 Male fecundity stimulation: conflict and cooperation within and between the sexes: model analyses and coevolutionary dynamics. American Naturalist 175 174-185. (doi:10.1086/649596)
2. Anderson MJ & Dixon AF 2002 Motility and themid-piece. Nature 416 496. (doi:10.1038/416496a)
3. Anderson MJ, Nyholt J & Dixon AF 2005 Sperm competition and the evolution of sperm midpiece volume in mammals. Journal of Zoology 267 135-142. (doi:10.1017/S0952836905007284)
4. Arnqvist G & Nilsson T 2000 The evolution of polyandry: multiple mating and female fitness in insects. Animal Behaviour 60 145-164. (doi:10. 1006/anbe.2000.1446)
5. Au DWT, Chiang MWL, Tang JYM, Yuen BBH, Wang YL & Wu RSS 2002 Impairment of sea urchin sperm quality by UV-B radiation: predicting fertilization success from sperm motility. Marine Pollution Bulletin 44 583-589. (doi:10.1016/S0025-326X(01)0288-0)
6. Badawy A, Elnashar A & Eltotongy M 2009 Effect of sperm morphology and number on success of intrauterine insemination. Fertility and Sterility 91 777-781. (doi:10.1016/j.fertnstert.2007.12.010)
7. Baer B & Boomsma JJ 2004 Male reproductive investment and queen mating-frequency in fungus growing ants. Behavioral Ecology 15 426-432. (doi:10.1093/beheco/arh025)
8. Ball MA & Parker GA 2003 Sperm competition games: sperm selection by females. Journal of Theoretical Biology 224 27-42. (doi:10.1016/S0022-5193(03) 0118-8)
9. Balshine S, Leach BJ, Neat F, Werner NY & Montgomerie R 2001 Sperm size of African cichlids in relation to sperm competition. Behavioral Ecology 12 726-731. (doi:10.1093/beheco/12.6.726)
10. delBarco-Trillo J 2011 Adjustment of sperm allocation under high risk of sperm competition across taxa: a meta-analysis. Journal of Evolutionary Biology 24 1706-1714. (doi:10.1111/j.1420-9101.2011.02293.x)
11. Barratt CLR, Tomlinson MJ & Cooke ID 1993 Prognostic significance of computerized motility analysis for in vivo fertility. Fertility and Sterility 60 520-525.
12. Bateman AJ 1948 Intrasexual selection in Drosophila. Heredity 2 349-368. (doi:10.1038/hdy.1948.21)
13. Birkhead TR & Fletcher F 1995 Depletion determines sperm numbers in male zebra finches. Animal Behaviour 49 451-456. (doi:10.1006/anbe. 1995.0058)
14. Birkhead TR & Møller AP 1998 Sperm Competition and Sexual Selection. London: Academic Press.
15. Birkhead TR, Martinez JG, Burke T & Froman DP 1999 Sperm mobility determines the outcome of sperm competition in the domestic fowl. Proceedings of the Royal Society of London. Series B: Biological Sciences 266 1759-1764. (doi:10.1098/rspb.1999.0843)
16. Birkhead TR, Pellatt EJ, Brekke P, Yeates R & Castillo-Juarez H 2005 Genetic effects on sperm design in the zebra finch. Nature 434 383-387. (doi:10.1038/nature03374)
17. den Boer SPA, Boomsma JJ & Baer B 2008 Seminal fluid enhances sperm viability in the leafcuter ant Atta colombica. Behavioral Ecology and Sociobiology 62 1843-1850. (doi:10.1007/s00265-008-0613-5)
18. den Boer SPA, Baer B & Boomsma JJ 2010 Seminal fluid mediates ejaculate competition in social insects. Science 327 1506-1509. (doi:10.1126/ science.1184709)
19. Boschetto C, Gasparini C & Pilastro A 2011 Sperm number and velocity affect sperm competition success in the guppy (Poecilia reticulata) Behavioral Ecology and Sociobiology 65 813-821. (doi:10.1007/ s00265-010-1085-y)
20. Breed WG & Taylor J 2000 Body mass, testes mass, and sperm size in murine rodents. Journal of Mammology 81 758-768. (doi:10.1644/1545- 1542(2000) 81!0758:BMTMASO2.3.CO;2)
21. Briskie JV & Montgomerie R 1992 Sperm size and sperm competition in birds. Proceedings of the Royal Society of London. Series B: Biological Sciences 247 89-95. (doi:10.1098/rspb.1992.0013)
22. Bryja J, Patzenhauerová H, Albrecht T, Mosansky L, Stanko M & Stopka P 2008 Varying levels of female promiscuity in four Apodemus mice species. Behavioral Ecology and Sociobiology 63 251-260. (doi:10.1007/s00265- 008-0656-7)
23. Byrne PG, Roberts JD & Simmons LW 2002 Sperm competition selects for increased testes mass in Australian frogs. Journal of Evolutionary Biology 15 347-355. (doi:10.1046/j.1420-9101.2002.00409.x)
24. Byrne PG, Simmons LW & Roberts JD 2003 Sperm competition and the evolution of gamete morphology in frogs. Proceedings of the Royal Society of London. Series B: Biological Sciences 270 2079-2086. (doi:10.1098/rspb.2003. 2433)
25. Calhim S & Birkhead TR 2007 Testes size in birds: quality versus quantity - assumptions, errors, and estimates. Behavioral Ecology 18 271-275. (doi:10.1093/beheco/arl076)
26. Calhim S, Immler S & Birkhead TR 2007 Postcopulatory sexual selection is associated with reduced variation in sperm morphology. PLoS ONE 2 e413. (doi:10.1371/journal.pone.0000413)
27. Calhim S, Double MC, Margraf N, Birkhead TR & Cockburn A 2011 Maintenance of sperm variation in a highly promiscuous wild bird. PLoS ONE 6 e28809. (doi:10.1371/journal.pone.0028809)
28. Cameron E, Day T & Rowe L 2007 Sperm competition and the evolution of ejaculate composition. American Naturalist 169 E158-E172. (doi:10. 1086/516718)
29. Carter RV 1985 Testis size in sandpipers: the fertilization frequency hypothesis. Naturwissenschaften 72 157-158. (doi:10.1007/BF00 490407)
30. Casselman SJ, Schulte-Hostedde AI & Montgomerie R 2006 Sperm quality influences male fertilization success in walleye (Sander vitreus) Canadian Journal of Fisheries and Aquatic Sciences 63 2119-2125. (doi:10.1139/f06-108)
31. Chapman T 2008 The soup in my fly: evolution, form and function of seminal fluid proteins. PLoS Biology 6 e179. (doi:10.1371/journal.pbio. 0060179)
32. Clark NL & Swanson WJ 2005 Pervasive adaptive evolution in primate seminal proteins. PLoS Genetics 1 e35. (doi:10.1371/journal.pgen. 0010035)
33. Clark NL, Aagaard JE & Swanson WJ 2006 Evolution of reproductive proteins from animals and plants. Reproduction 131 11-22. (doi:10. 1530/rep.1.00357)
34. Coker CR, McKinney F, Hays H, Briggs SV & Cheng KM 2002 Intromittent organ morphology and testis size in relation to mating system in waterfowl. Auk 119 403-413. (doi:10.1642/0004-8038(2002) 19[0403: IOMATS]2.0.CO;2)
35. Cook PA & Wedell N 1999 Non-fertile sperm delay female remating. Nature 397 486. (doi:10.1038/17257)
36. Cornwallis CK & Birkhead TR 2007 Changes in sperm quality and numbers in response to experimental manipulation of male social status and female attractiveness. American Naturalist 170 758-770. (doi:10.1086/ 521955)
37. Cornwallis CK & O'Conner EA 2009 Sperm: seminal fluid interactions and the adjustment of sperm quality in relation to female attractiveness. Proceedings of the Royal Society of London. Series B: Biological Sciences 276 3467-3475. (doi:10.1098/rspb.2009.0807)
38. Crean AJ & Marshall DJ 2008 Gamete plasticity in a broadcast spawning marine invertebrate. PNAS 105 13508-13513. (doi:10.1073/pnas. 0806590105)
39. Crudgington HS, Fellows S, Badcock NS & Snook RR 2009 Experimental manipulation of sexual selection promotes greater male mating capacity but does not alter sperm investment. Evolution 63 926-938. (doi:10. 1111/j.1558-5646. 2008.00601.x)
40. Dean MD, Findlay GD, Hoopman MR, Wu CC, MacCoss MJ, Swanson WJ & Nachman MW 2011 Identification of ejaculated proteins in the house mouse (Mus domesticus) via isotopic labeling. BMC Genomics 12 306. (doi:10.1186/1471-2164- 12-306)
41. Demary KC & Lewis SM 2007 Male reproductive allocation in fireflies (Photinus spp.) Invertebrate Biology 126 74-80. (doi:10.1111/j.1744- 7410.2007.00078.x)
42. Denk AG, Holzmann A, Peters A, Vermeirssen ELM & Kempenaers B 2005 Paternity in mallards: effects of sperm quality and female sperm selection for inbreeding avoidance. Behavioral Ecology 16 825-833. (doi:10. 1093/beheco/ari065)
43. Dewsbury DA 1982 Ejaculate cost and male choice. American Naturalist 119 601-610. (doi:10.1086/283938)
44. Donnelly ET, Lewis SEM, McNally JA & Thompson W 1998 In vitro fertilization and pregnancy rates: the influence of sperm motility and morphology on IVF outcome. Fertility and Sterility 70 305-314. (doi:10. 1016/S0015-0282(98) 0146-0)
45. Dorus S, Evans PD, Wyckoff GJ, Choi SS & Lahn BT 2004 Rate of molecular evolution of the seminal protein gene SEMG2 correlates with levels of female promiscuity. Nature Genetics 36 1326-1329. (doi:10.1038/ ng1471)
46. Drevet JR 2006 The antioxidant glutathione peroxidase family and spermatozoa: a complex story. Molecular and Cellular Endocrinology 250 70-79. (doi:10.1016/j.mce.2005.12.027)
47. Dunn PO, Whittingham LA & Hill GE 2001 Mating systems, sperm competition, and the evolution of sexual dimorphism in birds. Evolution 55 161-175.
48. Dziminski MA, Roberts JD, Beveridge M & Simmons LW 2009 Sperm competitiveness in frogs: slow and steady wins the race. Proceedings of the Royal Society of London. Series B: Biological Sciences 276 3955-3961. (doi:10.1098/rspb.2009.1334)
49. Dziminski MA, Roberts JD, Beveridge M & Simmons LW 2010a Amongpopulation covariation between sperm competition and ejaculate expenditure in frogs. Behavioral Ecology 21 322-328. (doi:10.1093/ beheco/arp191)
50. Dziminski MA, Roberts JD & Simmons LW 2010b Sperm morphology, motility, and fertilization capacity in the myobatrachid frog Crinia georgiana. Reproduction, Fertility, and Development 22 516-522. (doi:10.1071/RD09124)
51. Eberhard WG 1996 Female Control: Sexual Selection by Cryptic Female Choice. Princeton: Princeton University Press.
52. Emerson SB 1997 Testis size variation in frogs: testing the alternatives. Behavioral Ecology and Sociobiology 41 227-236. (doi:10.1007/ s002650050383)
53. Engqvist L & Reinhold K 2005 Pitfalls in experiments testing predictions from sperm competition theory. Journal of Evolutionary Biology 18 116-123. (doi:10.1111/j.1420-9101.2004.00792.x)
54. Findlay GD, Yi X, MacCoss MJ & Swanson WJ 2008 Proteomics reveals novel Drosophila seminal fluid proteins transferred at mating. PLoS Biology 6 e178. (doi:10.1371/journal.pbio.0060178)
55. Firman RC & Simmons LW 2008a The frequency of multiple paternity predicts variation in testes size among island populations of house mice. Journal of Evolutionary Biology 21 1524-1533. (doi:10.1111/j.1420- 9101.2008.01612.x)
56. Firman RC & Simmons LW 2008b Polyandry, sperm competition, and reproductive success in mice. Behavioral Ecology 19 695-702. (doi:10. 1093/beheco/arm158)
57. Firman RC & Simmons LW 2009 Sperm competition and the evolution of the sperm hook in house mice. Journal of Evolutionary Biology 22 2505-2511. (doi:10.1111/j.1420-9101.2009.01867.x)
58. Firman RC & Simmons LW 2010a Experimental evolution of sperm competitiveness in a mammal. BMC Evolutionary Biology 11 19 (doi:10.1186/1471- 2148-1111-1119)
59. Firman RC & Simmons LW2010b Experimental evolution of spermquality via postcopulatory sexual selection in house mice. Evolution 64 1245-1256. (doi:10.1111/j.1558-5646.2009.00894.x)
60. Firman RC, Cheam LY & Simmons LW 2011 Sperm competition does not influence sperm hook morphology in selection lines of house mice. Journal of Evolutionary Biology 24 856-862. (doi:10.1111/j.1420-9101. 2010.02219.x)
61. Fisher HS & Hoekstra HE 2010 Competition drives cooperation among related sperm of deer mice. Nature 463 801-803. (doi:10.1038/ nature08736)
62. Fitzpatrick JL & Baer B 2011 Polyandry reduces sperm length variation in social insects. Evolution 65 3006-3012. (doi:10.1111/j.1558-5646. 2011.01343.x)
63. Fitzpatrick JL, Montgomerie R, Desjardins JK, Stiver KA, Kolm N & Balshine S 2009 Female promiscuity promotes the evolution of faster sperm in cichlid fishes. PNAS 106 1128-1132. (doi:10.1073/pnas. 0809990106)
64. Fitzpatrick JL, García-González F & Evans JP 2010 Linking sperm length and velocity: the importance of intramale variation. Biology Letters 6 797-799. (doi:10.1098/rsbl.2010.0231)
65. Fitzpatrick JL, Almbro M, Gonzalez-Voyer A, Hamada S, Pennington C, Scanlan J & Kolm N 2012a Sexual selection uncouples the evolution of brain and body size in pinnipeds. Journal of Evolutionary Biology 25 1321-1330. (doi:10.1111/j.1420-9101.2012.02520.x)
66. Fitzpatrick JL, Almbro M, Gonzalez-Voyer A, Kolm N & Simmons LW 2012b Male contest competition and the coevolution of weaponry and testes in pinnipeds. Evolution (doi:10.1111/j.1558-5646.2012. 01713.x)
67. Fitzpatrick JL, Kempster R, Daly-Engel TS, Collin SP & Evans JP 2012c Assessing the potential for postcopulatory sexual selection in elasmobranchs. Journal of Fish Biology 80 1141-1158.
68. Fitzpatrick JL, Simmons LW & Evans JP 2012d Complex patterns of multivariate selection on the ejaculate of a broadcast spawning marine invertebrate. Evolution 66 2451-2460. (doi:10.1111/j.1558-5646.2012. 01627.x)
69. Fraser LR & Osiguwa OO 2004 Human sperm responses to calcitonin, angiotensin II and fertilization-promoting peptide in prepared semen samples from normal donors and infertility patients. Human Reproduction 19 596-606. (doi:10.1093/humrep/deh126)
70. Froman DP & Feltmann AJ 1998 Sperm mobility: a quantitative trait of the domestic fowl (Gallus domesticus) Biology of Reproduction 58 379-384. (doi:10.1095/biolreprod58.2.379)
71. Froman DP, Feltmann AJ, Rhoads ML & Kirby JD 1999 Sperm mobility: a primary determinant of fertility in the domestic fowl (Gallus domesticus) Biology of Reproduction 61 400-405. (doi:10.1095/ biolreprod61.2.400)
72. Fromhage L 2012 Mating unplugged: a model for the evolution of mating plug (dis-) lacement. Evolution 66 31-39. (doi:10.1111/j.1558-5646. 2011.01406.x)
73. Fry CL & Wilkinson GS 2004 Sperm survival in female stalk-eyed flies depends on seminal fluid and meiotic drive. Evolution 58 1622-1626. (doi:10.1111/j.0014-3820.2004.tb01743.x)
74. Gage MJG 1994 Associations between body size, mating pattern, testis size and sperm lengths across butterflies. Proceedings of the Royal Society of London. Series B: Biological Sciences 258 247-254. (doi:10.1098/rspb. 1994.0169)
75. Gage MJG 1995 Continuous variation in reproductive strategy as an adaptive response to population density in the moth Plodia interpunctella. Proceedings of the Royal Society of London. Series B: Biological Sciences 261 25-30. (doi:10.1098/rspb.1995.0112)
76. Gage MJG & Freckleton RP 2003 Relative testis size and sperm morphometry across mammals: no evidence for an association between sperm competition and sperm length. Proceedings of the Royal Society of London. Series B: Biological Sciences 270 625-632. (doi:10.1098/rspb. 2002.2258)
77. Gage MJG & Morrow EH 2003 Experimental evidence for the evolution of numerous, tiny sperm via sperm competition. Current Biology 13 754-757. (doi:10.1016/S0960-9822(03) 0282-3)
78. Gage MJG, Parker GA, Nylin S & Wiklund C 2002 Sexual selection and speciation in mammals, butterflies and spiders. Proceedings of the Royal Society of London. Series B: Biological Sciences 269 2309-2316. (doi:10.1098/rspb.2002. 2154)
79. Gage MJG, Macfarlane CP, Yeates S, Ward RG, Searle JB & Parker GA 2004 Spermatozoal traits and sperm competition in Atlantic salmon: relative sperm velocity is the primary determinant of fertilization success. Current Biology 14 44-47. (doi:10.1016/j.cub.2003.12.028)
80. Garamszegi LZ, Eens M, Erritzøe J & Møller AP 2005 Sperm competition and sexually size dimorphic brains in birds. Proceedings of the Royal Society of London. Series B: Biological Sciences 272 159-166. (doi:10.1098/rspb.2004.2940)
81. García-González F & Simmons LW 2005a The evolution of polyandry: intrinsic sire effects contribute to embryo viability. Journal of Evolutionary Biology 18 1097-1103. (doi:10.1111/j.1420-9101.2005.00889.x)
82. García-González F & Simmons LW 2005b Sperm viability matters in insect sperm competition. Current Biology 15 271-275. (doi:10.1016/j.cub. 2005.01.032)
83. García-González F & Simmons LW 2007a Paternal indirect genetic effects on offspring viability and the benefits of polyandry. Current Biology 17 32-36. (doi:10.1016/j.cub.2006.10.054)
84. García-González F & Simmons LW 2007b Shorter sperm confer higher competitive fertilization success. Evolution 61 816-824. (doi:10.1111/j. 1558-5646.2007.00084.x)
85. Gasparini C, Simmons LW, Beveridge M & Evans JP 2010 Sperm swimming velocity predicts competitive fertilization success in the green swordtail Xiphophorus helleri. PLoS ONE 5 e12146. (doi:10.1371/journal.pone. 0012146)
86. Ginsberg JR & Rubenstein DJ 1990 Sperm competition and variation in zebra mating behavior. Behavioral Ecology and Sociobiology 26 427-434. (doi:10.1007/BF00170901)
87. Goldman N & Yang Z 1994 A codon-based model of nucleotide substitution for protein-coding DNA sequences. Molecular Biology and Evolution 11 725-736.
88. Gomendio M & Roldan ERS 1991 Sperm competition influences sperm size in mammals. Proceedings of the Royal Society of London. Series B: Biological Sciences 243 181-185. (doi:10.1098/rspb.1991.0029)
89. Gomendio M & Roldan ERS 2008 Implications of diversity in sperm size and function for sperm competition and fertility. International Journal of Developmental Biology 52 439-447. (doi:10.1387/ijdb.082595mg)
90. Gomendio M, Martin-Coello J, Crespo C, Magaña C & Roldan ERS 2006 Sperm competition enhances functional capacity of mammalian spermatozoa. PNAS 103 15113-15117. (doi:10.1073/pnas.0605795103)
91. Gomendio M, Malo AF, Garde J & Roldan ERS 2007 Sperm traits and male fertility in natural populations. Reproduction 134 19-29. (doi:10.1530/ REP-07-0143)
92. Gomendio M, Tourmente M & Roldan ERS 2011 Why mammalian lineages respond differently to sexual selection: metabolic rate constrains the evolution of sperm size. Proceedings of the Royal Society of London. Series B: Biological Sciences 278 3135-3141. (doi:10.1098/ rspb.2011.0275)
93. Gravance CG, Liu IKM, Davis RO, Hughes JP & Casey PJ 1996 Quantification of normal head morphometry of stallion spermatozoa. Journal of Reproduction and Fertility 108 41-46. (doi:10.1530/jrf.0. 1080041)
94. Haerty W, Jagadeeshan S, Kulathinal RJ, Wong A, Ram KR, Sirot LK, Levesque L, Artieri CG, Wolfner MF, Civetta A et al. 2007 Evolution in the fast lane: rapidly evolving sex-related genes in Drosophila. Genetics 177 1321-1335. (doi:10.1534/genetics.107.078865)
95. Harcourt AH, Harvey PH, Larson SG & Short RV 1981 Testis weight, body weight and breeding system in primates. Nature 293 55-57. (doi:10.1038/ 293055a0)
96. Harcourt AH, Purvis A & Liles L 1995 Sperm competition: mating system, not breeding season, affects testes size of primates. Functional Ecology 9 468-476. (doi:10.2307/2390011)
97. Hayashi F 1998 Sperm co-operation in the fishfly, Parachauliodes japonicus. Functional Ecology 12 347-350. (doi:10.1046/j.1365-2435.1998. 00205.x)
98. Herndon LA & Wolfner MF 1995 A Drosophila seminal fluid protein, Acp26Aa, stimulates egg laying in females for 1 day after mating. PNAS 92 10114-10118. (doi:10.1073/pnas.92.22.10114)
99. Heske EJ & Ostfeld RS 1990 Sexual dimorphism in size, relative size of testes, and mating systems in North American voles. Journal of Mammology 71 510-519. (doi:10.2307/1381789)
100. Higginson DM & Pitnick S 2010 Evolution of intra-ejaculate sperm interactions: do sperm cooperate? Biological Reviews 86 249-270. (doi:10.1111/j.1469-185X.2010.00147.x)
101. Hirai M, Boersma A, Hoeflich A, Wolf E, Föll J, Aumüller R & Braun J 2001 Objectively measured sperm motility and sperm head morphometry in boars (Sus scrofa) relation to fertility and seminal plasma growth factors. Journal of Andrology 22 104-110.
102. Hodgson DJ & Hosken DJ 2006 Sperm competition promotes the exploitation of rival ejaculates. Journal of Theoretical Biology 243 230-234. (doi:10.1016/j.jtbi.2006.06.024)
103. Holman L 2009 Drosophila melanogaster seminal fluid can protect the sperm of other males. Functional Ecology 23 180-186. (doi:10.1111/j. 1365-2435.2008.01509.x)
104. Holman L & Snook RR 2008 A sterile sperm caste protects brother fertile sperm from female-mediated death in Drosophila pseudoobscura. Current Biology 18 292-296. (doi:10.1016/j.cub.2008.01.048)
105. Holman L, Freckleton RP & Snook RR 2008 What use is an infertile sperm? A comparative study of sperm-heteromorphic Drosophila Evolution 62 374-385. (doi:10.1111/j.1558-5646.2007.00280.x)
106. Holt C, Holt WV, Moore HDM, Reed HCB & Curnock RM 1997 Objectively measured boar sperm motility parameters correlate with the outcomes of on-farm inseminations: results of two fertility trials. Journal of Andrology 18 312-323.
107. Hosken DJ 1997 Sperm competition in bats. Proceedings of the Royal Society of London. Series B: Biological Sciences 264 385-392. (doi:10.1098/rspb.1997.0055)
108. Hosken DJ 1998 Testes mass in megachiropteran bats varies in accordance with sperm competition theory. Behavioral Ecology and Sociobiology 44 169-177. (doi:10.1007/s002650050529)
109. Hosken DJ & Ward PI 2001 Experimental evidence for testis size evolution via sperm competition. Ecology Letters 4 10-13. (doi:10.1046/j.1461- 0248.2001.00198.x)
110. Humphries S, Evans JP & Simmons LW 2008 Sperm competition: linking form to function. BMC Evolutionary Biology 8 319. (doi:10.1186/1471- 2148-8-319)
111. Hunter FM & Birkhead TR 2002 Sperm viability and sperm competition in insects. Current Biology 12 121-123. (doi:10.1016/S0960-9822(01) 00647-9)
112. Immler S 2008 Sperm competition and sperm cooperation: the potential role of diploid and haploid expression. Reproduction 135 275-283. (doi:10.1530/REP-07-0482)
113. Immler S & Birkhead TR 2007 Sperm competition and sperm midpiece size: no consistent pattern in passerine birds. Proceedings of the Royal Society of London. Series B: Biological Sciences 274 561-568. (doi:10.1098/ rspb.2006.3752)
114. Immler S, Moore HDM, Breed WG & Birkhead TR 2007a By hook or by crook? Morphometry, competition and cooperation in rodent sperm PLoS ONE 1 e170. (doi:10.1371/journal.pone.0000170)
115. Immler S, Saint-Jalme M, Lesobre L, Sorci G, Roman Y & Birkhead TR 2007b The evolution of sperm morphometry in pheasants. Journal of Evolutionary Biology 20 1008-1014. (doi:10.1111/j.1420-9101.2007. 01302.x)
116. Immler S, Calhim S & Birkhead TR 2008 Increased postcopulatory sexual selection reduces the intramale variation in sperm design. Evolution 62 1538-1543. (doi:10.1111/j.1558-5646.2008.00393.x)
117. Immler S, Pryke SR, Birkhead TR & Griffith SC 2010 Pronounced within-individual plasticity in sperm morphometry across social environments. Evolution 64 1634-1643. (doi:10.1111/j.1558-5646. 2009.00924.x)
118. Immler S, Pitnick S, Parker GA, Durrant KL, Lüpold S, Calhim S & Birkhead TR 2011 Resolving variation in the reproductive tradeoff between sperm size and number. PNAS 108 5325-5330. (doi:10.1073/ pnas.1009059108)
119. Jasko DJ, Little TV, Lein DH & Foote RH 1992 Comparison of spermatozoal movement and semen characteristics with fertility in stallions: 64 cases (1987-1988) Journal of the American Veterinary Medical Association 200 879-985.
120. Johnson DDP & Briskie JV 1999 Sperm competition and sperm length in shorebirds. Condor 101 848-854. (doi:10.2307/1370074)
121. Joly D & Schiffer M 2010 Coevolution of male and female reproductive structures in Drosophila. Genetica 138 105-118. (doi:10.1007/s10709- 009-9392-9)
122. Joly D, Luck N & DeJonghe B 2008 Adaptation to long sperm in Drosophila: correlated development of the sperm roller and sperm packaging. Journal of Experimental Zoology 310B 167-178. (doi:10.1002/jez.b. 21167)
123. Kappeler PM 1997 Intrasexual selection and testis size in strepsirhine primates. Behavioral Ecology 8 10-19. (doi:10.1093/beheco/8.1.10)
124. Karlsson B 1995 Resource allocation and mating systems in butterflies. Evolution 49 955-961. (doi:10.2307/2410417)
125. Karlsson B 1996 Male reproductive reserves in relation to mating system in butterflies: a comparative study. Proceedings of the Royal Society of London. Series B: Biological Sciences 263 187-192. (doi:10.1098/rspb. 1996.0030)
126. Karn RC, Clark NL, Nguyen ED & Swanson WJ 2008 Adaptive evolution in rodent seminal vesicle secretion proteins. Molecular Biology and Evolution 25 2301-2310. (doi:10.1093/molbev/msn182)
127. Kelly CD & Jennions MD 2011 Sexual selection and sperm quantity: metaanalyses of strategic ejaculation. Biological Reviews 86 863-884. (doi:10.1111/j.1469-185X.2011.00175.x)
128. Kilgallon SJ & Simmons LW 2005 Image content influences mens semen quality. Biology Letters 1 235-255. (doi:10.1098/rsbl.2005.0324)
129. Kleven O, Laskemoen T, Fossoy F, Robertson RJ & Lifjeld JT 2008 Intraspecific variation in sperm length is negatively related to sperm competition in passerine birds. Evolution 62 494-499. (doi:10.1111/j. 1558-5646.2007.00287.x)
130. Krause W 1995 Computer-assisted semen analysis systems: comparison with routine evaluation and prognostic value in male fertility and assisted reproduction. Human Reproduction 10 60-66.
131. Kvarnemo C & Simmons LW 2004 Testes investment and spawning mode in pipefishes and seahorses (Sygnathidae) Biological Journal of the Linnean Society 83 369-376. (doi:10.1111/j.1095-8312.2004. 00395.x)
132. LaMunyon CW & Ward S 1998 Larger sperm outcompete smaller sperm in the nematode Caenorhabditis elegans. Proceedings of the Royal Society of London. Series B: Biological Sciences 265 1997-2002. (doi:10.1098/ rspb.1998.0531)
133. LaMunyon CW & Ward S 1999 Evolution of sperm size in nematodes: sperm competition favours larger sperm. Proceedings of the Royal Society of London. Series B: Biological Sciences 266 263-267. (doi:10.1098/rspb. 1999.0631)
134. Lemaître J-F, Ramm SA, Barton RA & Stockley P 2009 Sperm competition and brain size in mammals. Journal of Evolutionary Biology 22 2215-2221. (doi:10.1111/j.1420-9101.2009.01837.x)
135. Lemaître J-F, Ramm SA, Hurst JL & Stockley P 2011 Social cues of sperm competition influence accessory reproductive gland size in a promiscuous mammal. Proceedings of the Royal Society of London. Series B: Biological Sciences 278 1171-1176. (doi:10.1098/rspb.2010.1828)
136. Levitan DR 2000 Sperm velocity and longevity trade off each other and influence fertilization in the sea urchin Lytechinus variegatus. Proceedings of the Royal Society of London. Series B: Biological Sciences 267 531-534. (doi:10.1098/rspb.2000.1032)
137. Liljedahl S, Rudolfsen G & Folstad I 2008 Factors predicting male fertilization success in an external fertilizer. Behavioral Ecology and Sociobiology 62 1805-1811. (doi:10.1007/s00265-008-0609-1)
138. Lindholmer C 1974 The Importance of seminal plasma for human sperm motility. Biology of Reproduction 10 533-542. (doi:10.1095/biolreprod10.5.533)
139. Linklater JR, Wertheim B, Wigby S & Chapman T 2007 Ejaculate depletion patterns evolve in response to experimental manipulation of sex ratio in Drosophila melanogaster. Evolution 61 2027-2034. (doi:10.1111/j. 1558-5646.2007.00157.x)
140. Liu H & Kubli E 2003 Sex-peptide is the molecular basis of the sperm effect in Drosophila melanogaster. PNAS 100 9929-9933. (doi:10.1073/pnas. 1631700100)
141. Lüpold S, Calhim S, Immler S & Birkhead TR 2009a Sperm morphology and sperm velocity in passerine birds. Proceedings of the Royal Society of London. Series B: Biological Sciences 276 1175-1181. (doi:10.1098/ rspb.2008.1645)
142. Lüpold S, Linz GM & Birkhead TR 2009b Sperm design and variation in the new world blackbirds (Icteridae) Behavioral Ecology and Sociobiology 63 899-909. (doi:10.1007/s00265-009-0733-6)
143. Lüpold S, Linz GM, Rivers JW, Westneat DF & Birkhead TR 2009c Sperm competition selects beyond relative testes size in birds. Evolution 63 391-402. (doi:10.1111/j.1558-5646.2008.00571.x)
144. Lüpold S, Manier MK, Berben KS, Smith KJ, Daley BD, Buckley SH, Belote JM & Pitnick S 2012 How multivariate ejaculate traits determine competitive fertilization success in Drosophila melanogaster. Current Biology 22 1667-1672.
145. Malo AF, Garde JJ, Soler AJ, García AJ, Gomendio M & Roldan ERS 2005 Male fertility in natural populations of red deer is determined by sperm velocity and the proportion of normal spermatozoa. Biology of Reproduction 72 822-829. (doi:10.1095/biolreprod.104.036368)
146. Marconato A & Shapiro DY 1996 Sperm allocation, sperm production and fertilization rates in the bucktooth parrotfish. Animal Behaviour 52 971-980. (doi:10.1006/anbe.1996.0245)
147. Marshburn PB, McIntire D, Carr BR & Byrd W 1992 Spermatozoal characteristics from fresh and frozen donor semen and their correlation with fertility outcome after intrauterine insemination. Fertility and Sterility 58 179-186.
148. Martin PA, Reimers RJ, Lodge JR & Dziuk PJ 1974 The effect of ratios and numbers of spermatozoa mixed from two males on proportions of offspring. Journal of Reproduction and Fertility 39 251-258. (doi:10.1530/jrf.0.0390251)
149. Martin-Coello J, Dopazo H, Arbiza L, Ausió J, Roldan ERS & Gomendio M 2009 Sexual selection drives weak positive selection in protamine genes and high promoter divergence, enhancing sperm competitiveness. Proceedings of the Royal Society of London. Series B: Biological Sciences 276 2427-2436. (doi:10.1098/rspb.2009.0257)
150. Metz EC, Robles-Sikisaka R & Vacquier VD 1998 Nonsynonymous substitution in abalone sperm fertilization genes exceeds substitution in introns and mitochondrial DNA. PNAS 95 10676-10681. (doi:10.1073/ pnas.95.18.10676)
151. Miller GT & Pitnick S 2002 Sperm-female coevolution in Drosophila. Science 298 1230-1233. (doi:10.1126/science.1076968)
152. Møller AP 1988 Ejaculate quality, testes size and sperm competition in primates. Journal of Human Evolution 17 479-488. (doi:10.1016/0047- 2484(88) 0037-1)
153. Møller AP 1989 Ejaculate quality, testes size and sperm production in mammals. Functional Ecology 3 91-96. (doi:10.2307/2389679)
154. Møller AP 1991 Sperm competition, sperm depletion, paternal care, and relative testis size in birds. American Naturalist 137 882-906. (doi:10.1086/285199)
155. Møller AP & Briskie JV 1995 Extra-pair paternity, sperm competition and the evolution of testis size in birds. Behavioral Ecology and Sociobiology 36 357-365. (doi:10.1007/BF00167797)
156. Montgomerie R & Fitzpatrick JL 2009 Testis size, sperm size and sperm competition. In Reproductive Biology and Phylogeny of Fishes, pp 1-53. Ed. BGM Jamieson. Enfield, NH: Science Publishers, Inc.
157. Montoto LG, Magana C, Tourmente M, Martin-Coello J, Crespo C, Luque- Larena JJ, Gomendio M & Roldan ERS 2011a Sperm competition, sperm numbers and sperm quality in muroid rodents. PLoS ONE 6 e18173. (doi:10.1371/journal. pone.0018173)
158. Montoto LG, Sánchez MV, TourmenteM, Martín-Coello J, Luque-Larena JJ, Gomendio M & Roldan ERS 2011b Sperm competition differentially affects swimming velocity and size of spermatozoa from closely related muroid rodents: head first. Reproduction 142 819-830. (doi:10.1530/ REP-11-0232)
159. Moore HDM & Akhondi MA 1996 Fertilizing capacity of rat spermatozoa is correlated with decline in straight-line velocity measured by continuous computer-aided sperm analysis: epididymal rat spermatozoa from the proximal cauda have a greater fertilizing capacity in vitro than those from the distal cauda or vas deferens. Journal of Andrology 17 50-60.
160. Moore H, Dvorakova K, Jenkins N & Breed W 2002 Exceptional sperm cooperation in the wood mouse. Nature 418 174-177. (doi:10.1038/ nature00832)
161. Morrow EH & Gage MJG 2000 The evolution of sperm length in moths. Proceedings of the Royal Society of London. Series B: Biological Sciences 267 307-313. (doi:10.1098/rspb.2000.1001)
162. Morrow EH & Gage MJG 2001 Sperm competition experiments between lines of crickets producing different sperm lengths. Proceedings of the Royal Society of London. Series B: Biological Sciences 268 2281-2286. (doi:10.1098/rspb.2001. 1807)
163. Nakatsuru K & Kramer DL 1982 Is sperm cheap? Limited male fertility and female choice in the lemon tetra (Pisces, Choracidae) Science 216 753-755. (doi:10.1126/science.216.4547.753)
164. Nascimento JM, Shi LZ, Meyers S, Gagneux P, Loskutoff NM, Botvinick EL & Berns MW 2008 The use of optical tweezers to study sperm competition and motility in primates. Journal of the Royal Society, Interface/the Royal Society 5 297-302. (doi:10.1098/rsif.2007.1118)
165. Olsen PD 1991 Do large males have small testes? A note on allometric variation and sexual size dimorphism in raptors Oikos 60 134-136. (doi:10.2307/3545004)
166. Olsson M, Madeson T & Shine R 1997 Is sperm really so cheap? Costs of reproduction in male adders, Vipera berus Proceedings of the Royal Society of London. Series B: Biological Sciences 264 455-459. (doi:10.1098/rspb.1997.0065)
167. Oppliger A, Naciri-Graven Y, Ribi G & Hosken DJ 2003 Sperm length influences fertilization success during sperm competition in the snail Viviparus ater. Molecular Ecology 12 485-492. (doi:10.1046/j.1365- 294X.2003.01748.x)
168. Parker GA 1970 Sperm competition and its evolutionary consequences in the insects. Biological Reviews 45 525-567. (doi:10.1111/j.1469-185X. 1970.tb01176.x)
169. Parker GA 1982 Why are there so many tiny sperm? Sperm competition and the maintenance of two sexes Journal of Theoretical Biology 96 281-294. (doi:10.1016/0022-5193(82) 0225-9)
170. Parker GA 1993 Sperm competition games: sperm size and sperm number under adult control. Proceedings of the Royal Society of London. Series B: Biological Sciences 253 245-254. (doi:10.1098/rspb.1993.0110)
171. Parker GA & Begon M 1993 Sperm competition games: sperm size and number under gametic control. Proceedings of the Royal Society of London. Series B: Biological Sciences 253 255-262. (doi:10.1098/rspb. 1993.0111)
172. Parker GA & Pizzari T 2010 Sperm competition and ejaculate economics. Biological Reviews 85 897-934.
173. Parker GA, Ball MA, Stockley P & Gage MJG 1997 Sperm competition games: a prospective analysis of risk assessment. Proceedings of the Royal Society of London. Series B: Biological Sciences 264 1793-1802. (doi:10.1098/rspb.1997.0249)
174. Parker GA, Immler S, Pitnick S & Birkhead TR 2010 Sperm competition games: sperm size (mass) and number under raffle and displacement and the evolution of P2. Journal of Theoretical Biology 264 1003-1023. (doi:10.1016/j.jtbi.2010.03.003)
175. Pattarini JM, Starmer WT, Bjork A & Pitnick S 2006 Mechanisms underlying the sperm quality advantage in Drosophila melanogaster. Evolution 60 2064-2080. (doi:10.1111/j.0014-3820.2006.tb01844.x)
176. Petersen CW & Warner RR 1998 Sperm competition in fishes. In Sperm Competition and Sexual Selection, pp 435-464. Eds TR Birkhead & AP Møller. London: Academic Press.
177. Pilch B & Mann M 2006 Large-scale and high-confidence proteomic analysis of human seminal plasma. Genome Biology 7 R40 (doi:10.1186/ gb-2006-7-5-r40)
178. Pitcher TE, Dunn PO & Whittingham LA 2005 Sperm competition and the evolution of testis size in birds. Journal of Evolutionary Biology 18 557-567. (doi:10.1111/j.1420-9101.2004.00874.x)
179. Pitnick S 1996 Investment in testes and the cost of making long sperm in Drosophila. American Naturalist 148 57-80. (doi:10.1086/285911)
180. Pitnick S, Miller GT, Reagan J & Holland B 2001 Males' evolutionary responses to experimental removal of sexual selection. Proceedings of the Royal Society of London. Series B: Biological Sciences 268 1071-1080. (doi:10.1098/rspb.2001.1621)
181. Pitnick S, Hosken DJ & Birkhead TR 2009a Sperm morphological diversity. In Sperm Biology: an Evolutionary Perspective, pp 69-149. Eds TR Birkhead, DJ Hosken & S Pitnick. Burlington, MA: Academic Press.
182. Pitnick S, Wolfner MF & Suarez SS 2009b Ejaculate-female and spermfemale interactions. In Sperm Biology: an Evolutionary Approach, pp 247-301. Eds TR Birkhead, DJ Hosken & S Pitnick. London: Academic Press.
183. Pizzari T & Foster KR 2008 Sperm sociality: cooperation, altruism, and spite. PLoS Biology 6 e130. (doi:10.1371/journal.pbio.0060130)
184. Pizzari T & Parker GA 2009 Sperm competition and sperm phenotype. In Sperm Biology: an Evolutionary Approach, pp 207-245. Eds TR Birkhead, DJ Hosken & S Pitnick. London: Academic Press.
185. Pizzari T, Worley K, Burke T & Froman DP 2008 Sperm competition dynamics: ejaculate fertilising efficiency changes differentially with time. BMC Evolutionary Biology 8 332. (doi:10.1186/1471-2148-8-332)
186. Poiani A 2006 Complexity of seminal fluid: a review. Behavioral Ecology and Sociobiology 60 289-310. (doi:10.1007/s00265-006-0178-0)
187. Poulin R & Morand S 2000 Testes size, body size and male-male competition in acanthocephalan parasites. Journal of Zoology 250 551-558.
188. Prado CPdA & Haddad CFB 2003 Testes size in Leptodactylid frogs and occurrence of multimale spawning in the genus Leptodactylus in Brazil. Journal of Herpetology 37 354-362. (doi:10.1670/0022-1511(2003) 37 [0354:TSILFA]2.0. CO;2)
189. Pyron M 2000 Testes mass and reproductive mode of minnows. Behavioral Ecology and Sociobiology 48 132-136. (doi:10.1007/s002650000191)
190. Radwan J 1996 Intraspecific variation in sperm competition success in the bulb mite: a role for sperm size. Proceedings of the Royal Society of London. Series B: Biological Sciences 263 855-859. (doi:10.1098/rspb. 1996.0126)
191. Ram RK & Wolfner MF 2007 Seminal influences: Drosophila Acps and the molecular interplay between males and females during reproduction. Integrative and Comparative Biology 47 427-445. (doi:10.1093/icb/ icm046)
192. Ramm SA & Stockley P 2010 Sperm competition and sperm length influence the rate of mammalian spermatogenesis. Biology Letters 6 219-221. (doi:10.1098/rsbl.2009.0635)
193. Ramm SA, Parker GA & Stockley P 2005 Sperm competition and the evolution of male reproductive anatomy in rodents. Proceedings of the Royal Society of London. Series B: Biological Sciences 272 949-955. (doi:10.1098/rspb.2004.3048)
194. Ramm SA, McDonald L, Hurst JL, Beynon RJ & Stockley P 2009 Comparative proteomics reveals evidence for evolutionary diversification of rodent seminal fluid and its functional significance in sperm competition. Molecular Biology and Evolution 26 189-198. (doi:10.1093/molbev/msn237)
195. Rose RW, Nevison CM & Dixson AF 1997 Testes weight, body weight and mating systems in marsupials and monotremes. Journal of Zoology 243 523-531. (doi:10.1111/j.1469-7998.1997.tb02798.x)
196. Rowe M & Pruett-Jones S 2011 Sperm competition selects for sperm quantity and quality in the Australian Maluridae. PLoS ONE 6 e15720. (doi:10.1371/journal.pone.0015720)
197. Rudolfsen G, Figenschou L, Folstad I, Tveiten H & Figenschou M 2006 Rapid adjustments of sperm characteristics in relation to social status. Proceedings of the Royal Society of London. Series B: Biological Sciences 273 325-332. (doi:10.1098/rspb.2005.3305)
198. Scharer L, Ladurner P & Rieger RM 2004 Bigger testes do work more: experimental evidence that testis size reflects testicular cell proliferation activity in the marine invertebrate, the free-living flatworm Macrostomum sp. Behavioral Ecology and Sociobiology 56 420-425. (doi:10.1007/s00265-004-0802-9)
199. Sheldon BC 1994 Male phenotype, fertility, and the pursuit of extra-pair copulations by female birds. Proceedings of the Royal Society of London. Series B: Biological Sciences 257 25-30. (doi:10.1098/rspb.1994.0089)
200. Shulman A, Hauser R, Lipitz S, Frenkel Y, Dor J, BiderD, Mashiach S, Yogev L & Yavetz H 1998 Sperm motility is a major determinant of pregnancy outcome following intrauterine insemination. Journal of Assisted Reproduction and Genetics 15 381-385. (doi:10.1023/A:1022585000740)
201. Simmons LW 2001 Sperm Competition and its Evolutionary Consequences in the Insects. Princeton: Princeton University Press.
202. Simmons LW 2005 The evolution of polyandry: sperm competition, sperm selection, andoffspring viability.AnnualReviewof Ecologyand Systematics 36 125-146. (doi:10.1146/annurev.ecolsys.36.102403.112501)
203. Simmons LW & García-González F 2008 Evolutionary reduction in testes size and competitive fertilization success in response to the experimental removal of sexual selection in dung beetles. Evolution 62 2580-2591. (doi:10.1111/j.1558-5646.2008.00479.x)
204. Simmons LW & Beveridge M 2011 Seminal fluid affects sperm viability in a cricket. PLoS ONE 6 e17975. (doi:10.1371/journal.pone.0017975)
205. Simmons LW, Wernham J, García-González F & Kamien D 2003 Variation in paternity in the field cricket Teleogryllus oceanicus: no detectable influence of sperm numbers or sperm length. Behavioral Ecology 14 539-545. (doi:10.1093/beheco/arg038)
206. Simmons LW, Denholm A, Jackson C, Levy E & Madon E 2007a Male crickets adjust ejaculate quality with both risk and intensity of sperm competition. Biology Letters 3 520-522. (doi:10.1098/rsbl.2007.0328)
207. Simmons LW, Emlen DJ & Tomkins JL 2007b Sperm competition games between sneaks and guards: a comparative analysis using dimorphic male beetles. Evolution 61 2684-2692. (doi:10.1111/j.1558-5646.2007. 00243.x)
208. Sirot LK, Buehner N, Fiumera AC & Wolfner MF 2009 Seminal fluid protein depletion and replenishment in the fruit fly, Drosophila melanogaster: an ELISA-basedmethod for tracking individual ejaculates. Behavioral Ecology and Sociobiology 63 1505-1513. (doi:10.1007/s00265-009-0806-6)
209. Sirot LK, Wolfner MF & Wigby S 2011 Protein-specific manipulation of ejaculate composition in response to female mating status in Drosophila melanogaster. PNAS 108 9922-9926. (doi:10.1073/pnas.1100905108)
210. Skjaeraasen JE, Mayer I, Meager JJ, Rudolfsen G, Karlsen O, Haugland T & Kleven O 2009 Sperm characteristics and competitive ability in farmed and wild cod. Marine Ecology Progress Series 375 219-228. (doi:10.3354/meps07774)
211. Slatyer RA, Mautz BS, Backwell PRY & Jennions MD 2012 Estimating genetic benefits of polyandry from experimental studies: a meta-analysis. Biological Reviews 87 1-33. (doi:10.1111/j.1469-185X.2011.00182.x)
212. Smith CC 2012 Opposing effects of sperm viability and velocity on the outcome of sperm competition. Behavioral Ecology 23 820-826. (doi:10.1093/beheco/ars036)
213. Smith CC & Ryan MJ 2011 Tactic-dependent plasticity in ejaculate traits in the swordtail Xiphophorus nigrensis. Biology Letters 7 733-735. (doi:10.1098/rsbl.2011.0286)
214. Snook RR 2005 Sperm in competition: not playing by the numbers. Trends in Ecology & Evolution 20 46-53. (doi:10.1016/j.tree.2004.10.011)
215. Soulsbury CD 2010 Genetic patterns of paternity and testes size in mammals. PLoS ONE 5 e9581. (doi:10.1371/journal.pone.0009581)
216. Stockley P, Gage MJG, Parker GA & Møller AP 1997 Sperm competition in fishes: the evolution of testis size and ejaculate characteristics. American Naturalist 149 933-954. (doi:10.1086/286031)
217. Stutchbury BJ & Morton ES 1995 The effect of breeding synchrony on extrapair mating systems in songbirds. Behaviour 132 675-690. (doi:10.1163/ 156853995X00081)
218. Sutkeviciene N, Riskeviciene V, Januskauskas A, Zilinskas H & Andersson M 2009 Assessment of sperm quality traits in relation to fertility in boar semen. Acta Veterinaria Scandinavica 51 53. (doi:10.1186/1751-0147-51-53)
219. Takami Y & Sota T 2007 Sperm competition promotes diversity of sperm bundles in Ohomopterus ground beetles. Die Naturwissenschaften 94 543-550. (doi:10.1007/s00114-007-0225-3)
220. Thomas ML & Simmons LW 2007 Male crickets adjust the viability of their sperm in response to female mating status. American Naturalist 170 190-195. (doi:10.1086/519404)
221. Thomas ML & Simmons LW 2008 Male-derived cuticular hydrocarbons signal sperm competition intensity and affect ejaculate expenditure in crickets. Proceedings of the Royal Society of London. Series B: Biological Sciences 276 383-388. (doi:10.1098/rspb.2008.1206)
222. Till-Bottraud I, Joly D, Lachaise D & Snook RR 2005 Pollen and sperm heteromorphism: convergence across kingdoms? Journal of Evolutionary Biology 18 1-18. (doi:10.1111/j.1420-9101.2004.00789.x)
223. Tourmente M, Gomendio M, Roldan ERS, Giojalas LC & Chiaraviglio M 2009 Sperm competition and reproductive mode influence sperm dimensions and structure among snakes. Evolution 63 2513-2524. (doi:10.1111/j.1558-5646.2009. 00739.x)
224. Tourmente M, Gomendio M & Rolando A 2011a Sperm competition and the evolution of sperm design in mammals. BMC Evolutionary Biology 11 12. (doi:10.1186/1471-2148-11-12)
225. Tourmente M, Gomendio M & Roldan ERS 2011b Mass-specific metabolic rate and sperm competition determine sperm size in marsupial mammals. PLoS ONE 6 e21244. (doi:10.1371/journal.pone.0021244)
226. Vahed K & Parker DJ 2012 The evolution of large testes: sperm competition or male mating rate? Ethology 118 107-117. (doi:10.1111/j.1439-0310. 2011.01991.x)
227. Vahed K, Parker DJ & Gilbert JDJ 2011 Larger testes are associated with a higher level of polyandry, but a smaller ejaculate volume, across bushcricket species (Tettigoniidae) Biology Letters 7 261-264. (doi:10.1098/rsbl.2010.0840)
228. Veveris-Lowe TL, Kruger SJ, Walsh T, Gardiner RA & Clements JA 2007 Seminal fluid characterization for male fertility and prostate cancer: kallikrein-related serine proteases and whole proteome approaches. Seminars in Thrombosis and Hemostasis 33 87-99. (doi:10.1055/s-2006- 958467)
229. Wagstaff BJ & Begun DJ 2007 Adaptive evolution of recently duplicated accessory gland protein genes in desert Drosophila. Genetics 177 1023-1030. (doi:10.1534/genetics.107.077503)
230. Wedell N, Gage MJG & Parker GA 2002 Sperm competition, male prudence and sperm-limited females. Trends in Ecology & Evolution 17 313-320. (doi:10.1016/S0169-5347(02) 2533-8)
231. Wigby S & Chapman T 2004 Female resistance to male harm evolves in response to manipulation of sexual conflict. Evolution 58 1028-1037.
232. Wigby S, Sirot LK, Linklater JR, Buehner N, Calboli FCF, Bretman A, Wolfner MF & Chapman T 2009 Seminal fluid protein allocation and male reproductive success. Current Biology 19 751-757. (doi:10.1016/j. cub.2009.03.036)
233. Willett EL & Ohms JI 1957 Measurement of testicular size and its relation to production of spermatozoa by bulls. Journal of Dairy Science 40 1559-1569. (doi:10.3168/jds.S0022-0302(57) 4678-7)
234. Youn JS, Cha SH, Park CW, Yang KM, Kim JY, Koong MK, Kang IS, Song IO & Han SC 2011 Predictive value of sperm motility characteristics assessed by computer-assisted sperm analysis in intrauterine insemination with superovulation in couples with unexplained infertility. Clinical and Experimental Reproductive Medicine 38 47-52. (doi:10.5653/cerm. 2011.38.1.47)