Reproductive Competition and Sexual Selection in Horseshoe Crabs



The four species of horseshoe crabs share many similarities but differ in the intensity of reproductive competition. Although all horseshoe crabs nest synchronously, only Limulus polyphemus, the American horseshoe crab, has intense male–male competition (high operational sex ratios and multi-male groups around nesting pairs) and very high female nesting densities. These differences in reproductive competition are reflected in differences between American and Asian species (Tachypleus gigas, T. tridentatus, or Carcinoscorpius rotundicauda) in their reproductive structures and in egg and sperm size. However, the American and Asian species do not differ in the degree of sexual dimorphism in body size. The intensity of reproductive competition is correlated with nesting density in L. polyphemus, but this is not the case in the Asian species, which rarely have multi-male groups or highly male-biased operational sex ratios.


Sperm Competition Sexual Size Dimorphism Horseshoe Crab Nest Density Asian Species 



The research described in this chapter was supported by the National Science Foundation, Sigma Xi Grants-In-Aid of Research, the University of Delaware, College of Marine Sciences, the University of Florida Foundation, the Department of Zoology, and the Seahorse Key Marine Laboratory. The research in Florida was conducted under special use permits from the Cedar Keys National Wildlife Refuge. The Delaware research was conducted with permission from the Cape Henlopen State Park.


  1. Andersson M (1994) Sexual Selection. Princeton University Press, PrincetonGoogle Scholar
  2. Arak A (1983) Male-male competition and mate choice in anuran amphibians. In: Bateson PB (ed) Mate Choice. Cambridge University Press, Cambridge, pp. 181–210Google Scholar
  3. Baptist JP, Smith OR, Ropes JW (1957) Migrations of the horseshoe crab, Limulus polyphemus in Plum Island sound, Massachusetts. US Fish and Wildlife Service Special Scientific Report – Fisheries No. 220, 1–15Google Scholar
  4. Barlow RB, Ireland LC, Kass L (1982) Vision has a role in Limulus mating behaviour. Nature 296:65–66PubMedCrossRefGoogle Scholar
  5. Barlow RB, Powers MK (2003) Seeing at night and finding mates: the role of vision. In: Shuster CN Jr, Barlow RB, Brockmann HJ (eds) The American Horseshoe Crab. Harvard University Press, Cambridge, pp. 83–102Google Scholar
  6. Barlow RB, Powers MK, Howard H, Kass L (1986) Migration of Limulus for mating: relation to lunar phase, tide height, and sunlight. Biol Bull 171:310–329CrossRefGoogle Scholar
  7. Barlow RB, Powers MK, Howard H, Kass L (1987) Vision in Limulus mating and migration. In: Herrnkind WF, Thistle AB (eds) Signposts in the Sea. Florida State University Press, Tallahassee, FL, pp. 69–84Google Scholar
  8. Botton ML (2009) The ecological importance of horseshoe crabs in estuarine and coastal communities: A review and speculative summary. In: Tanacredi JT, Botton ML, Smith DR (eds) Biology and Conservation of Horseshoe Crabs. Springer, New York, pp 45–63CrossRefGoogle Scholar
  9. Botton ML, Loveland RE (1989) Reproductive risk: high mortality associated with spawning by horseshoe crabs (Limulus polyphemus) in Delaware Bay, USA. Mar Biol 101:143–151CrossRefGoogle Scholar
  10. Botton ML, Loveland RE (1992) Body size, morphological constraints, and mated pair formation in four populations of horseshoe crabs (Limulus polyphemus) along a geographic cline. Mar Biol 112:409–415CrossRefGoogle Scholar
  11. Botton ML, Loveland RE, Jacobsen TR (1988) Beach erosion and geochemical factors: influence on spawning success of horseshoe crabs (Limulus polyphemus) in Delaware Bay. Mar Biol 99:325–332CrossRefGoogle Scholar
  12. Botton ML, Loveland RE, Tanacredi JT, Itow T (2006) Horseshoe crabs (Limulus polyphemus) in an urban estuary (Jamaica Bay, New York) and the potential for ecological restoration. Estuar Coasts 29:820–830Google Scholar
  13. Botton ML, Loveland RE, Tiwari A (2003a) Distribution, abundance, and survivorship of young-of-the-year in a commercially exploited population of horseshoe crabs Limulus polyphemus. Mar Ecol Prog Ser 265:175–184CrossRefGoogle Scholar
  14. Botton ML, Harrington BA, Tsipoura N, Mizrahi D (2003b) Synchronies in migration: shorebirds, horseshoe crabs, and Delaware Bay. In: Shuster CN Jr, Barlow RB, Brockmann HJ (eds) The American Horseshoe Crab. Harvard University Press, Cambridge pp. 5–32Google Scholar
  15. Botton ML, Shuster CN, Sekiguchi K, Sugita H (1996) Amplexus and mating behavior in the Japanese horseshoe crab, Tachypleus tridentatus. Zool Sci 13:151–159CrossRefGoogle Scholar
  16. Brady JT, Schrading E (1997) Habitat suitability index models: horseshoe crab (spawning beaches) – Delaware Bay, New Jersey and Delaware. Unpublished Report for the U.S. Army Corps of EngineersGoogle Scholar
  17. Brockmann HJ (1990) Mating behavior of horseshoe crabs, Limulus polyphemus. Behaviour 114:206–220CrossRefGoogle Scholar
  18. Brockmann HJ (1996) Satellite male groups in horseshoe crabs, Limulus polyphemus. Ethology 102:1–21CrossRefGoogle Scholar
  19. Brockmann HJ (2002) An experimental approach to altering mating tactics in male horseshoe crabs (Limulus polyphemus). Behav Ecol 13:232–238CrossRefGoogle Scholar
  20. Brockmann HJ (2003a) Nesting behavior: a shoreline phenomenon. In: Shuster CN Jr, Barlow RB, Brockmann HJ (eds) The American Horseshoe Crab. Harvard University Press, Cambridge, pp. 33–49Google Scholar
  21. Brockmann HJ (2003b) Male competition and satellite behavior. In: Shuster CN Jr, Barlow RB, Brockmann HJ (eds) The American Horseshoe Crab. Harvard University Press, Cambridge, pp. 50–82Google Scholar
  22. Brockmann HJ (in prep) A Long-term Study of Spawning Activity in a Florida Gulf Coast Population of Horseshoe Crabs (Limulus polyphemus). Unpublished manuscriptGoogle Scholar
  23. Brockmann HJ, Colson T, Potts W (1994) Sperm competition in horseshoe crabs (Limulus polyphemus). Behav Ecol Sociobiol 35:153–160CrossRefGoogle Scholar
  24. Brockmann HJ, Nguyen C, Potts W (2000) Paternity in horseshoe crabs when spawning in multiple-male groups. Anim Behav 60:837–849PubMedCrossRefGoogle Scholar
  25. Brockmann HJ, Penn D (1992) Male mating tactics in the horseshoe crab, Limulus polyphemus. Anim Behav 44:653–665CrossRefGoogle Scholar
  26. Brousseau LJ, Sclafani M, Smith DR, Carter DB (2004) Acoustic-tracking and radio-tracking of horseshoe crabs to assess spawning behavior and subtidal habitat use in Delaware Bay. N Am J Fish Manage 24:1376–1384CrossRefGoogle Scholar
  27. Brown GG, Knouse JR (1973) Effects of sperm concentration, sperm aging, and other variables on fertilization in the horseshoe crab, Limulus polyphemus. Biol Bull 144:462–470CrossRefGoogle Scholar
  28. Burton RS (1983) Protein polymorphisms and genetic differentiation of marine invertebrate populations. Mar Biol Lett 4:193–206Google Scholar
  29. Byrne PG, Roberts JD, Simmons LW (2002) Sperm competition selects for increased testis mass in Australian frogs. J Evol Biol 15:347–355.CrossRefGoogle Scholar
  30. Carmichael RH, Rutecki D, Valiela I (2003) Abundance and population structure of the Atlantic horseshoe crab Limulus polyphemus in Pleasant Bay, Cape Cod. Mar Ecol Prog Ser 246:225–239CrossRefGoogle Scholar
  31. Chatterji A (1994) The Horseshoe Crab – A Living Fossil. Project Swaarajya Publication, Dona Paula, GoaGoogle Scholar
  32. Chatterji A (1995) Fecundity of the Indian horseshoe crab, Tachypleus gigas (Muller) from Balramgari (Orissa). Pak J Mar Sci 4:127–131Google Scholar
  33. Chatterji A, Parulekar AH (1992) Fecundity of the Indian horse-shoe crab, Carcinoscorpius rotundicauda (Latreille). Trop Ecol 33:97–102Google Scholar
  34. Chatterji BP, Vijayakumar R, Parulekar AH (1992) Spawning migration of the Indian horseshoe crab, Tachypleus gigas (Muller) with lunar cycle. Asian Fish Sci 5:123–128Google Scholar
  35. Chen CP, Yeh HY, Lin PF (2004) Conservation of the horseshoe crab at Kinmen, Taiwan: strategies and practices. Biodivers Conserv 13:1889–1904CrossRefGoogle Scholar
  36. Chiu HMC, Morton B (1999) The distribution of horseshoe crabs (Tachypleus tridentatus and Carcinoscorpius rotundicauda) in Hong Kong. Asian Mar Biol 16:185–194Google Scholar
  37. Chiu, HMC, Morton B (2001) Growth and allometry of two horseshoe crab species, Tachypleus tridentatus and Carcinoscorpius rotundicauda (Xiphosura), in Hong Kong. Asian Mar Bio 18:129–141Google Scholar
  38. Chiu HMC, Morton B (2003) The sediment and hydrographic characteristics of three horseshoe crab nursery beaches in Hong Kong. J Ocean Univ Qingdao Oceanic Coast Sea Res 2:35–43Google Scholar
  39. Chou NS, Cheng C (1950) On the biology of the king-crab, Tachypleus tridentatus Leach. Amoy Fish Bull 1:29–40Google Scholar
  40. Clutton-Brock T, Harvey P, and Rudder B (1977) Sexual dimorphism, socionomic sex ratio, and bodyweight in primates. Nature 269:797–800PubMedCrossRefGoogle Scholar
  41. Cohen JA, Brockmann HJ (1983) Breeding activity and mate selection in the horseshoe crab, Limulus polyphemus. Bull Mar Sci 33:274–281Google Scholar
  42. Conner J (1989) Density-dependent sexual selection in the fungus beetle, Bolitotherus cornatus. Evolution 43:1378–1386CrossRefGoogle Scholar
  43. Duffy EE, Penn DJ, Botton ML, Brockmann HJ, Loveland RE (2006) Eye and clasper damage influence male mating tactics in the horseshoe crab, Limulus polyphemus. J Ethol 24:67–74CrossRefGoogle Scholar
  44. Dumont JN, Anderson E (1967) Vitellogenesis in the horseshoe crab Limulus polyphemus. J Microsc 6:791–806Google Scholar
  45. Ehlinger GS, Tankersley RA, Bush MB (2003) Spatial and temporal patterns of spawning and larval hatching by the horseshoe crab, Limulus polyphemus, in a microtidal coastal lagoon. Estuaries 26:631–640CrossRefGoogle Scholar
  46. Fahrenbach WH (1973) Spermiogenesis in the horseshoe crab, Limulus polyphemus. J Morphol 140:31–52CrossRefGoogle Scholar
  47. Giese AC, Kanatani H (1987) Maturation and spawning. In: Giese AC, Pearse JS, Pearse VB (eds), Reproduction of Marine Invertebrates. Blackwell Scientific, Palo Alto, CA, pp. 251–329Google Scholar
  48. Goto S, Hattori O (1929) Notes on the spawning habits and growth stages of the Japanese king-crab. X Cong Int de Zoologie 2:1147–1155Google Scholar
  49. Groff JM, Leibovitz L (1982) A gill disease of Limulus polyphemus associated with triclad turbellarid worm infection. Biol Bull 163:392Google Scholar
  50. Hanna DH (2001) An estimate of population sizes of two horseshoe crabs (Limulus polyphemus) sites in Jamaica Bay. In: Tanacredi JT (ed) Limulus in the Limelight. Kluwer Academic/Plenum, New York, pp. 147–156Google Scholar
  51. Harari AR, Handler AM, Landolt PJ (1999) Size-assortative mating, male choice and female choice in the curculionid beetle Diaprepes abbreviatus. Anim Behav 58:1191–1200PubMedCrossRefGoogle Scholar
  52. Harrington JM, Armstrong PB (2003) A liposome-permeating activity from the surface of the carapace of the American horseshoe crab, Limulus polyphemus. Biol Bull 205: 205–206PubMedCrossRefGoogle Scholar
  53. Hassler C, Brockmann HJ (2001) Evidence for use of chemical cues by male horseshoe crabs when locating nesting females (Limulus polyphemus). J Chem Ecol 27: 2319–2335PubMedCrossRefGoogle Scholar
  54. Hong SG, Sun T, ZMN, Xue R (1995) Studies on spermatogenesis in Tachypleus tridentatus: I. The stages of spermatogenesis. Acta Zool Sinica 41:393–399Google Scholar
  55. Ishijima S, Sekiguchi K, Hiramoto Y (1988) Comparative-study of the beat patterns of American and Asian horseshoe-crab sperm – Evidence for a role of the central pair complex in forming planar waveforms in flagella. Cell Motil Cytoskel 9: 264–270CrossRefGoogle Scholar
  56. Itow T (2004) Living fossil horseshoe crabs continue to evolve. Zool Sci 21:1271Google Scholar
  57. Itow T, Mishra JK, Ahmed ATA (2004) Horseshoe crabs (king crabs) in the Bay of Bengal, South Asia. Bull Fac Educ Shizuoka Univ Nat Sci Ser 54:13–30Google Scholar
  58. James-Pirri MJ, Tuxbury K, Marino S, Koch S (2005) Spawning densities, egg densities, size structure, and movement patterns of spawning horseshoe crabs, Limulus polyphemus, within four coastal embayments on Cape Cod, Massachusetts. Estuaries 28:296–313CrossRefGoogle Scholar
  59. Jehl J, Murray BG (1986) The evolution of normal and reverse sexual size dimorphism in shorebirds and other birds. Curr Ornithol 3:1–86CrossRefGoogle Scholar
  60. Kaplan E, Barlow RB, Chamberlain SC, Stelzner DJ (1976) Mechanoreceptors on the dorsal carapace of Limulus. Brain Res 109:615–622PubMedCrossRefGoogle Scholar
  61. Kato H, Hara M, Etoh H (2005) Geographical variations in mitochondrial DNA sequence and morphological features of the horseshoe crab Tachypleus tridentatus. Biogeography 7: 55–59Google Scholar
  62. Khan RA (2003) Observations on some aspects of the biology of horse-shoe crab, Carcinoscorpius rotundicauda (Latreille) on mud flats of Sunderban estuarine region. Rec Zool Surv India 101:1–23Google Scholar
  63. King TL, Eackles MS, Spidle AP, Brockmann HJ (2005) Regional differentiation and sex-biased dispersal among populations of the horseshoe crab Limulus polyphemus. Trans Am Fish Soc 134:441–465CrossRefGoogle Scholar
  64. Kraeuter JN, Fegley SR (1994) Vertical disturbance of sediments by horseshoe crabs (Limulus polyphemus) during their spawning season. Estuaries 17:288–294CrossRefGoogle Scholar
  65. Kvarnemo C, Ahnesjö I (1996) The dynamics of operational sex ratios and competition for mates. Trends Ecol Evol 11:404–408PubMedCrossRefGoogle Scholar
  66. Laughlin R (1983) The effects of temperature and salinity on larval growth of the horseshoe crab Limulus polyphemus. Biol Bull 164:93–103CrossRefGoogle Scholar
  67. Leschen AS, Grady SP, Valiela I (2006) Fecundity and spawning of the Atlantic horseshoe crab, Limulus polyphemus, in Pleasant Bay, Cape Cod, Massachusetts, USA. Mar Ecol 27:54–65CrossRefGoogle Scholar
  68. Levitan DR (1998) Sperm limitation, gamete competition, and sexual selection in external fertilizers. In: Birkhead TR, Møller AP (eds) Sperm Competition and Sexual Selection. Academic Press, New York, pp. 175–217CrossRefGoogle Scholar
  69. Loveland RE, Botton ML (1992) Size dimorphism and the mating system in horseshoe crabs (Limulus polyphemus L.). Anim Behav 44:907–916CrossRefGoogle Scholar
  70. McLain DK (1987) Male choice, fighting ability, assortative mating and the intensity of sexual selection in the milkweed longhorn beetle, Tetraopes tetraophthalmus (Coleoptera, Cerambycidae) Behav Ecol Sociobiol 20:239–246CrossRefGoogle Scholar
  71. Mikkelsen T (1988) The Secret in the Blue Blood. Science Press, Beijing, ChinaGoogle Scholar
  72. Mitani JC, Gros-Louis J, Richards, F (1996) Sexual dimorphism, the operational sex ratio, and the intensity of male competition in polygynous primates. Am Nat 147:966–980CrossRefGoogle Scholar
  73. Miyazaki J, Sekiguchi K, Hirabayashi T (1987) Application of an improved method of two-dimensional electrophoresis to the systematic study of horseshoe crabs. Biol Bull 172:212–224CrossRefGoogle Scholar
  74. Moore S (2004) The Taunton Bay assessment. Report to Marine Resources Committee, Maine Legislature, Maine Department of Marine Resources, W. Boothbay Harbor, MaineGoogle Scholar
  75. Myers EM, Zamudio KR (2004) Multiple paternity in an aggregate breeding amphibian: the effect of reproductive skew on estimates of male reproductive success. Mol Ecol 13:1951–1963PubMedCrossRefGoogle Scholar
  76. Palumbi SR, Johnson BA (1982) A note on the influence of life-history stage on metabolic adaptation: the responses of Limulus eggs and larvae to hypoxia. In: Bonaventura J, Bonaventura C, Tesh S (eds) Physiology and Biology of Horseshoe Crabs: Studies on Normal and Environmentally Stressed Animals. Alan R. Liss, New York, pp. 115–124Google Scholar
  77. Penn D, Brockmann HJ (1994) Nest-site selection in the horseshoe crab, Limulus polyphemus. Biol Bull 187:373–384CrossRefGoogle Scholar
  78. Penn D, Brockmann HJ (1995) Age-biased stranding and righting in horseshoe crabs, Limulus polyphemus. Anim Behav 49:1531–1539CrossRefGoogle Scholar
  79. Pierce JC, Tan G, Gaffney PM (2000) Delaware Bay and Chesapeake Bay populations of the horseshoe crab Limulus polyphemus are genetically distinct. Estuaries 23:690–698CrossRefGoogle Scholar
  80. Pomerat CM (1933) Mating in Limulus polyphemus. Biol Bull 12:243–252CrossRefGoogle Scholar
  81. Rama Rao KV, Surya Rao KV (1972) Studies on Indian king crabs (Arachnida, Xiphosura). Proc Indian Nat Sci Acad B 38:206–211Google Scholar
  82. Riska B (1981) Morphological variation in the horseshoe crab Limulus polyphemus. Evolution 35:647–658CrossRefGoogle Scholar
  83. Roonwal ML (1944) Some observations on the breeding biology, and on the swelling, weight, water-content and embryonic movements in the developing eggs of the Moluccan king-crab, Tachypleus gigas (Muller) [Arthropoda, Xiphosura]. Proc Indian Nat Sci Acad B 20:115–129Google Scholar
  84. Rudloe A (1980) The breeding behavior and patterns of movement of horseshoe crabs, Limulus polyphemus, in the vicinity of breeding beaches in Apalachee Bay, Florida. Estuaries 3: 177–183CrossRefGoogle Scholar
  85. Rudloe A (1981) Aspects of the biology of juvenile horseshoe crabs, Limulus polyphemus. Bull Mar Sci 31:125–133Google Scholar
  86. Rudloe A (1985) Variation in the expression of lunar and tidal behavioral rhythms in the horseshoe crab, Limulus polyphemus. Bull Mar Sci 36:388–395Google Scholar
  87. Schaus JM, Sakaluk SK (2001) Ejaculate expenditures of male crickets in response to varying risk and intensity of sperm competition: not all species play games. Behav Ecol 12:740–745CrossRefGoogle Scholar
  88. Saunders NC, Kessler LG, Avise JC (1986) Genetic variation and geographic differentiation in mitochondrial DNA of the horseshoe crab, Limulus polyphemus. Genetics 112:613–627PubMedGoogle Scholar
  89. Schaller SY (2002) Horseshoe crab (Limulus polyphemus) spawning surveys in Maine, 2001. In: American Fisheries Society Annual Meeting, pp. abstract #24261566. American Fisheries Society, Baltimore, MDGoogle Scholar
  90. Schwab RL, Brockmann HJ (2007) The role of visual and chemical cues in the mating decisions of satellite male horseshoe crabs (Limulus polyphemus). Anim Behav 74:837–846CrossRefGoogle Scholar
  91. Sekiguchi K (1988a) Biogeography. In: Sekiguchi K (ed) Biology of Horseshoe Crabs. Science House, Tokyo, pp. 22–49Google Scholar
  92. Sekiguchi K (1988b) Ecology. In: Sekiguchi K (ed) Biology of Horseshoe Crabs. Science House, Tokyo, pp. 50–68Google Scholar
  93. Sekiguchi K, Nakamura K (1979) Ecology of the extant horseshoe crabs. In: Cohen E (ed) Biomedical Applications of the Horseshoe Crab (Limulidae). Alan R. Liss, New York, pp. 37–45Google Scholar
  94. Sekiguchi K, Nakamura K, Sen TK, Sugita H (1976) Morphological variation and distribution of a horseshoe crab, Tachypleus gigas, from the Bay of Bengal and the Gulf of Siam. Proc Jpn Soc Syst Zool 12:13–20Google Scholar
  95. Sekiguchi K, Nakamura K, Seshimo H (1978) Morphological variation and distribution of a horseshoe crab, Carcinoscorpius rotundicauda from the Bay of Bengal and the Gulf of Siam. Proc Jpn Soc Syst Zool 15:24–30Google Scholar
  96. Sekiguchi K, Nishiwaki S, Makioka T (1977) A study on the egg-laying habits of the horseshoe crabs, Tachypleus gigas and Carcinoscorpius rotundicauda in Chonburi area of Thailand. Proc Jpn Soc Syst Zool 13:39–45Google Scholar
  97. Sekiguchi K, Yamamichi Y, Seshimo H, Sugita H (1988) Normal Development. In: Sekiguchi K (ed) Biology of Horseshoe Crabs. Science House, Tokyo, pp. 133–224Google Scholar
  98. Semlitsch RD (1985) Reproductive strategy of a facultatively paedomorphic salamander Ambystoma talpoideum. Oecologia 65:305–313CrossRefGoogle Scholar
  99. Sullivan BK (1989) Mating system variation in Woodhouse’s toad (Bufo woodhousii). Ethology 83:60–68CrossRefGoogle Scholar
  100. Shuster CN Jr (1950) Observations on the natural history of the American horseshoe crab, Limulus polyphemus. In: Third Report on Investigations of Methods of Improving the Shellfish Resources of Massachusetts. Woods Hole Oceanographic Institution, Woods Hole, MA, pp. 18–23Google Scholar
  101. Shuster CN Jr (1953) Odyssey of the horseshoe crab. Audubon Mag 55:162–163, 167Google Scholar
  102. Shuster CN Jr (1955) On morphometric and serological relationships within the Limulidae, with particular reference to Limulus polyphemus L. PhD Dissertation, Department of Biology, New York University, New YorkGoogle Scholar
  103. Shuster CN Jr. (1982) A pictorial review of the natural history and ecology of the horseshoe crab Limulus polyphemus, with reference to other Limulidae. In: Bonaventura J, Bonaventura C, Tesh S (eds) Physiology and Biology of Horseshoe Crabs: Studies on Normal and Environmentally Stressed Animals. Alan R. Liss, New York, pp. 1–52Google Scholar
  104. Shuster CN Jr., Botton ML (1985) A contribution to the population biology of horseshoe crabs, Limulus polyphemus (L.) in Delaware Bay. Estuaries 8:363–572Google Scholar
  105. Smith DR (2007) Effect of horseshoe crab spawning density on nest disturbance and exhumation of eggs: a simulation study. Estuar Coasts 30:287–295Google Scholar
  106. Smith DR, Pooler PS, Loveland RE, Botton ML, Michels SE, Weber RG, Carter DB (2002a) Horseshoe crab (Limulus polyhemus) reproductive activity on Delaware Bay beaches: Interactions with beach characteristics. J Coast Res 18: 730–740Google Scholar
  107. Smith DR, Pooler PS, Swan BL, Michels S, Hall WR, Himchak P, Millard MJ (2002b) Spatial and temporal distribution of horseshoe crab (Limulus polyphemus) spawning in Delaware Bay: Implications for monitoring. Estuaries 25:115–125CrossRefGoogle Scholar
  108. Sokoloff A (1978) Observations on populations of the horseshoe crab Limulus (=Xiphosura) polyphemus. Res Popul Ecol 19:222–236CrossRefGoogle Scholar
  109. Suggs DN, Carmichael RH, Grady SP, Valiela I (2002) Effects of individual size on pairing in horseshoe crabs. Biol Bull 203:225–227PubMedCrossRefGoogle Scholar
  110. Swan BL (2005) Migrations of adult horseshoe crabs, Limulus polyphemus, in the Middle Atlantic Bight: A 17-year tagging study. Estuaries 28:28–40CrossRefGoogle Scholar
  111. Sydlik MA, Turner LL (1990) Behavioral observations of horseshoe crabs moving along shore. Mich Acad 22:115–124Google Scholar
  112. Tennessen JA, Zamudio KR (2003) Early male reproductive advantage, multiple paternity and sperm storage in an amphibian aggregate breeder. Mol Ecol 12:1567–1576PubMedCrossRefGoogle Scholar
  113. Tilney LG (1975) Actin filaments in the acrosomal reaction of Limulus sperm. J Cell Biol 64:289–310PubMedCrossRefGoogle Scholar
  114. van der Meer Mohr JC (1941) A note on two species of Malaysian king-crabs (Xiphosura). Treubia 18:201–205Google Scholar
  115. Waterman TH, Travis DF (1953) Respiratory reflexes and the flabellum of Limulus. J Cell Comp Anat 41:261–289CrossRefGoogle Scholar
  116. Watson WH III (1980a) Limulus gill cleaning behavior. J Comp Physiol 141:67–75CrossRefGoogle Scholar
  117. Watson WH III (1980b) Long-term patterns of gill cleaning, ventilation and swimming in Limulus. J Comp Physiol 141:77–85CrossRefGoogle Scholar
  118. Wedell N (1999) Butterflies tailor their ejaculate in response to sperm competition risk and intensity. Proc R Soc Lond B Bio 266:1033–1039CrossRefGoogle Scholar
  119. Wells KD (1977) The social behaviour of anuran amphibians. Anim Behav 25:666–693CrossRefGoogle Scholar
  120. Wenner E, Thompson M (2000) Evaluation of harvesting impacts and population trends for Limulus polyphemus in South Carolina. Marine Resources Research Institute, South Carolina Department of Natural Resources, Charleston, SC, pp. 91Google Scholar
  121. Yamasaki T, Makioka T, Saito J (1988) Morphology. In: Sekiguchi K (ed) Biology of Horseshoe Crabs. Science House, Tokyo, pp. 69–132Google Scholar
  122. Yund PO, McCartney MA (1994) Male reproductive success in sessile invertebrates: competition for fertilizations. Ecology 75:2151–2167CrossRefGoogle Scholar
  123. Zamudio KR, Chan LM (2008) Alternative reproductive tactics in amphibians. In: Oliveira R, Taborsky M, Brockmann HJ (eds) Alternative Reproductive Tactics. Cambridge University Press, Cambridge, pp. 300–331CrossRefGoogle Scholar

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© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  1. 1.Department of ZoologyUniversity of FloridaGainesvilleUSA

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