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Reproduction, Development and Life Cycles

  • Tiziana Altiero
  • Atsushi C. Suzuki
  • Lorena RebecchiEmail author
Chapter
Part of the Zoological Monographs book series (ZM, volume 2)

Abstract

In tardigrades reproduction occurs only through eggs, fertilized or unfertilized, and therefore only through gametes. Tardigrades exploit several reproductive modes, amphimixis, self-fertilization and thelytokous parthenogenesis (both apomixis and automixis). These modes are often in close relationship with the colonized environment. As regards sexuality, tardigrades can be gonochoristic (bisexual or unisexual) or hermaphroditic. The anatomy of the reproductive apparatus of males, females and hermaphrodites and the maturative patterns of male and female germinal elements are presented and discussed, as well as the ultrastructure of spermatozoa and eggs, including their phylogenetic implications. In addition, mating and fertilization patterns, embryonic and post-embryonic development, sexual dimorphism and parental care are considered and discussed. Finally, vegetative reproduction does not occur in tardigrades, and their capability to regenerate is limited to a physiological tissue restoration of a few cells.

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© Springer Nature Switzerland AG 2018

Authors and Affiliations

  • Tiziana Altiero
    • 1
  • Atsushi C. Suzuki
    • 2
  • Lorena Rebecchi
    • 3
    Email author
  1. 1.Department of Education and HumanitiesUniversity of Modena and Reggio EmiliaReggio EmiliaItaly
  2. 2.Department of BiologyUniversity of KeioYokohamaJapan
  3. 3.Department of Life SciencesUniversity of Modena and Reggio EmiliaModenaItaly

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