Behavioral Ecology and Sociobiology

, Volume 61, Issue 3, pp 365–370 | Cite as

Male mating opportunities affect sex allocation in a protrandric-simultaneous hermaphroditic shrimp

Original Article


Sex allocation theory predicts phenotypic adjustments by individuals in their investments into the male and female reproductive function in response to environmental conditions. I tested for phenotypically plastic shifts in sex allocation in a protandric simultaneous hermaphrodite, in which individuals mature and reproduce as males first, and later in life, as simultaneous hermaphrodites. I predicted that initially maturing males should adjust the timing of maturation as hermaphrodites according to male mating opportunities mediated by population size of hermaphrodites. In a first experiment, males maintained with only one hermaphrodite reduced the time they spent as males in comparison to males maintained with no conspecifics, presumably because total reproductive output is maximized by two individuals being simultaneous hermaphrodites when the mating system is a pair. Conversely, males maintained in groups with two or more hermaphrodites increased the time they spent as males in comparison to single males. This delay in maturation was not an effect of resource depletion with increasing shrimp density because the growth rate of males did not differ among most of the experimental treatments. One hypothesis to explain this social mediation of sex allocation is that the smaller males are more successful in mating as males than are the larger hermaphrodites: it will pay reproductively for males to delay maturation as hermaphrodites in large but not in small groups. In agreement with this notion, a second experiment demonstrated that smaller males were four times more successful than were larger hermaphrodites in inseminating shrimps reproducing as females. The informative cue that males may use to perceive different group sizes deserves further attention.


Sex allocation Phenotypic plasticity Social mediation Hermaphrodite 



The author thanks C.W. Petersen, R. Jaeger, M. Thiel, S. Martin, and S. Fuentes, for their insightful comments on the drafts of the manuscript. The helpful comments and suggestions of two anonymous reviewers are gratefully acknowledged. Thanks to J. Caskey and J. Noel for improving the language of the manuscript. This research was funded by a Sigma Xi Grant in Aid of Research, Lerner-Gray Fund for Marine Science (NMNH), and NSF Doctoral Dissertation Improvement Grant IBN No. 0506908 to J. A. Baeza, and NSF Grant No. 9982466 to R.T. Bauer. The author acknowledges a ‘President of the Republic’ fellowship (Chile). The experiments comply with the current laws of the United States of America.


  1. Allison PD (1995) Survival analysis using the SAS system: practical guide. SAS Institute, Cary, North Carolina, USAGoogle Scholar
  2. Andersson M (1994) Sexual Selection. Princeton Univ. Press, Princeton, New JerseyGoogle Scholar
  3. Baeza JA, Bauer RT (2004) Experimental test of socially mediated sex change in a protandric simultaneous hermaphrodite, the marine shrimp Lysmata wurdemanni (Caridea: Hippolytidae). Behav Ecol Sociobiol 55:544–550CrossRefGoogle Scholar
  4. Baldwin AP, Bauer RT (2003) Growth, survivorship, life span, and sex change in the hermaphroditic shrimp Lysmata wurdemanni (Decapoda: Caridea: Hippolytidae). Mar Biol 143:157–166CrossRefGoogle Scholar
  5. Bauer RT (2000) Simultaneous hermaphroditism in caridean shrimps: a unique and puzzling sexual system in the Decapoda. J Crustac Biol 20 (Spec. No. 2):116–128Google Scholar
  6. Bauer RT (2002a) Test of hypotheses on the adaptive value of an extended male phase in the hermaphroditic shrimp Lysmata wurdemanni (Caridea: Hippolytidae). Biol Bull 203:347–357PubMedGoogle Scholar
  7. Bauer RT (2002b) Reproductive ecology of a protandric simultaneous hermaphrodite, the shrimp Lysmata wurdemanni (Decapoda: Caridea: Hippolytidae). J Crustac Biol 22:742–749CrossRefGoogle Scholar
  8. Bauer RT, Holt GJ (1998) Simultaneous hermaphroditism in the marine shrimp Lysmata wurdemanni (Caridea: Hippolytidae): an undescribed sexual system in the decapod Crustacea. Mar Biol 132:223–235CrossRefGoogle Scholar
  9. Cadet C, Metz JAJ, Klinkhamer PGL (2004) Size and the not-no-single sex: disentangling the effects of size and budget on sex allocation in hermaphrodites. Am Nat 164:779–792CrossRefGoogle Scholar
  10. Charnov EL (1982) The Theory of Sex Allocation. Princeton Univ. Press, Princeton, New JerseyGoogle Scholar
  11. Collin R (1995) Sex, size, and position: a test of models predicting size at sex change in the protandrous gastropod Crepidula fornicata. Am Nat 146:815–831CrossRefGoogle Scholar
  12. Hamilton WD (1967) Extraordinary sex ratios. Science 156:477–488PubMedCrossRefGoogle Scholar
  13. Herre EA (1985) Sex ratio adjustment in fig wasps. Science 228:896–898CrossRefPubMedGoogle Scholar
  14. Locher R, Baur B (2000) Mating frequency and resource allocation to male and female function in the simultaneous hermaphrodite land snail Arianta arbustorum. J Evol Biol 13:607–614CrossRefGoogle Scholar
  15. Lorenzi MC, Sella G, Schleicherova D, Ramella L (2005) Outcrossing hermaphroditic polychaete worms adjust their sex allocation to social conditions. J Evol Biol 18:1341–1347PubMedCrossRefGoogle Scholar
  16. Munday PL, Caley MJ, Jones GP (1998) Bi-directional sex change in a coral-dwelling goby. Behav Ecol Sociobiol 43:371–377CrossRefGoogle Scholar
  17. Munday PL, Buston PM, Wagner RR (2006) Diversity and flexibility of sex-change strategies in animals. Trends Ecol Evol 21:89–95PubMedCrossRefGoogle Scholar
  18. Petersen CW (1991) Sex allocation in hermaphroditic sea basses. Am Nat 138:650–667CrossRefGoogle Scholar
  19. Petersen CW, Fischer EA (1996) Intraspecific variation in sex allocation in a simultaneous hermaphrodite: the effect of individual size. Evolution 50:636–645CrossRefGoogle Scholar
  20. Premoli MC, Sella G (1995) Sex economy in bethic polychaetes. Ethol Ecol Evol 7:27–48CrossRefGoogle Scholar
  21. SAS Institute (2001) SAS/STAT sofware; version 8.2. SAS Institute, Cary, North Carolina, USAGoogle Scholar
  22. Schärer L, Ladurner P (2003) Phenotypically plastic adjustment of sex allocation in a simultaneous hermaphrodite. Proc R Soc Lond B 270:935–941CrossRefGoogle Scholar
  23. Schleicherová D, Lorenzi MC, Sella G (2006) How outcrossing hermaphrodites sense the presence of conspecifics and suppress female allocation. Behav Ecol 17:1–5CrossRefGoogle Scholar
  24. Shuker DM, West SA (2004) Information constraints and the precision of adaptation: sex ratio manipulation in wasps. Proc Natl Acad Sci USA 101:10363–10367PubMedCrossRefGoogle Scholar
  25. St. Mary CM (1994) Sex allocation in a simultaneous hermaphrodite, the blue-banded goby (Lythrypnus dalli): the effects of body size and behavioral gender and the consequences for reproduction. Behav Ecol 5:304–311Google Scholar
  26. Stearns SC (1992) The evolution of life histories. Oxford University Press, New York, USAGoogle Scholar
  27. Tan GN, Govedich FR, Burd M (2004) Social group size, potential sperm competition and reproductive investment in a hermaphroditic leech, Helobdella papillornata (Euhirudinea: Glossiphoniidae). J Evol Biol 17:574–580PubMedCrossRefGoogle Scholar
  28. Tomiyama K (1996) Mate-choice criteria in a protandrous simultaneously hermaphroditic land snail Achatina fulica (Férussac) (Stylommatophora: Achatinidae). J Molluscan Stud 62:101–111Google Scholar
  29. Trouvé S, Jourdane J, Renaud F, Durand P, Morand S (1999) Adaptive sex allocation in a simultaneous hermaphrodite. Evolution 53:1599–1604CrossRefGoogle Scholar
  30. Warner RR, Fitch DL, Standish JD (1996) Social control of sex change in the shelf limpet, Crepidula norrisiarum: size-specific responses to local group composition. J Exp Mar Biol Ecol 204:155–167CrossRefGoogle Scholar
  31. Werren JH (1980) Sex ratio adaptations to local mate competition in a parasitic wasp. Science 208:1157–1159CrossRefPubMedGoogle Scholar
  32. Zhang D, Lin J (2005) Comparative mating success of smaller male-phase and larger male-role euhermaphrodite-phase shrimp, Lysmata wurdemanni (Caridea: Hyppolytidae). Mar Biol 147:1387–1392CrossRefGoogle Scholar
  33. Zucker N, Cunningham M, Adams HP (1997) Anatomical evidence for androdioecy in the clam shrimp Eulimnadia texana. Hydrobiologia 359:171–175CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  1. 1.Department of BiologyThe University of Louisiana at LafayetteLafayetteUSA

Personalised recommendations