Evolution of sex determination and sexually dimorphic larval sizes in parasitic barnacles

Sachi Yamaguchi, Jens T. Høeg, Yoh Iwasa

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The parasitic (rhizocephalan) barnacles include species of which larval sex is determined by the mother (genetic sex determination, GSD), male larvae are larger than female larvae, and a female accepts only two dwarf males who sire all the eggs laid by her. In contrast, other species of parasitic barnacles exhibit monomorphic larvae that choose to become male or female depending on the condition of the host they settle (environmental sex determination, or ESD), and a female accepts numerous dwarf males. Here, we ask why these set of traits are observed together, by examining the evolution of sex determination and the larval size. ESD has an advantage over GSD because each larva has a higher chance of encountering a suitable host. On the other hand, GSD has two advantages over ESD: the larval size can be chosen differently between sexes, and their larvae can avoid spending time for sex determination on the host. We conclude that, in species whose female accepts only two males, the male larvae engage in intense contest competition for reproductive opportunities, and male's success-size relation is very different from female's. Then, larvae with predetermined sex (GSD) with sexually dimorphic larvae is more advantageous than ESD. In contrast, in species whose females accept many dwarf males, the competition among males is less intense, and producing larvae with undetermined sex should evolve. We also discuss the condition for females to evolve receptacles to limit the number of males she accepts.

Original languageEnglish
Pages (from-to)7-16
Number of pages10
JournalJournal of Theoretical Biology
Volume347
Issue number1
DOIs
Publication statusPublished - Apr 21 2014

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All Science Journal Classification (ASJC) codes

  • Statistics and Probability
  • Modelling and Simulation
  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)
  • Agricultural and Biological Sciences(all)
  • Applied Mathematics

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