, Volume 558, Issue 1, pp 9–21 | Cite as

Encystment Processes and the “Matrioshka-like Stage” in a Moss-dwelling and in a Limnic Species of Eutardigrades (Tardigrada)

  • Roberto Guidetti
  • Deborah Boschini
  • Lorena Rebecchi
  • Roberto Bertolani


Tardigrades have two forms of dormancy, namely cryptobiosis and encystment. The encystment is a form of diapause known for a limited number of species of tardigrades and still little studied. To increase the knowledge on encystment, two species of eutardigrades from Italy have been considered: the moss-dwelling Amphibolus volubilis (Eohypsibiidae), and the limnic Dactylobiotus parthenogeneticus (Murrayidae). Cysts have been collected in nature, or induced under laboratory conditions. In the latter case, it was possible to follow the several steps of encystment processes. Two different types of cyst (“type 1” and “type 2”) have been found in A. volubilis, while in D. parthenogeneticus only one type has been found. In general, the ovoid-shaped cysts are constituted by a series of cuticles surrounding the animals and resemble an onion or a Matrioshka Russian doll. In all three types of cyst, the encystment processes show both common and peculiar traits. Encystment begins with the discharging of the sclerified parts of the buccal-pharyngeal apparatus, as in the molting process, but without the loss of the old cuticle. Then, two or three new cuticles are serially synthesized, according to cyst type. In A. volubilis, the ultrastructure of these new cuticular involucra is similar to that of non-encysted animal cuticles, while in D. parthenogeneticus the ultrastructure of the new cuticular involucra differs from that of non-encysted animal cuticle. A modified buccal-pharyngeal apparatus has been observed both in “type 2” cyst of A. volubilis and in the D. parthenogeneticus cyst.


dormancy diapause encystment Dactylobiotus parthenogeneticus Amphibolus volubilis 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Bertolani, R. 1981A new genus and five new species of Italian fresh-water tardigradesBollettino del Museo Civico di Storia Naturale Verona8249254Google Scholar
  2. Bertolani, R., Rebecchi, L. 1996The tardigrades of Emilia (Italy). II. Monte Rondinaio. A multihabitat study on a high altitude valley of the Northern ApenninesZoological Journal of the Linnean Society116312Google Scholar
  3. Crowe, J. H., Newell, I. M., Thomson, W. W. 1971Cuticle formation in the tardigrade, Macrobiotus areolatus MurrayJournal de Microscopie11121132Google Scholar
  4. Eibye-Jacobsen, J. 2001A new method for making SEM preparations of the tardigrade buccopharyngeal apparatusZoologischer Anzeiger240309321Google Scholar
  5. Guidetti, R., Rebecchi, L., Bertolani, R. 2000Cuticle structure and systematics of the Macrobiotidae (Tardigrada, Eutardigrada)Acta Zoologica812736CrossRefGoogle Scholar
  6. Hansen J. G. & A. K. Katholm, 2002. A study of the genus Amphibolus from Disko Island with special attention on the life cycle of Amphibolus nebulosus (Eutardigrada: Eohypsibiidae). In Hansen J. G. (ed.), Arctic Biology Field Course Quqertarsuaq 2002. Zoological Museum University of Copenhagen H.C.Ø. TRYK Copenhagen: 129–163Google Scholar
  7. Heinis, F. 1910Systematik und Biologie der Moosebewohnenden Rhizopoden, Rotatorien und Tardigraden uswArchiv für Hydrobiologie und Planktonkund.51115Google Scholar
  8. Kristensen, R. M. 1982The first record of cyclomorphosis in Tardigrada based on a new genus and species from Arctic meiobenthosZeitschrift für Zoologische Systematik und Evolutionsforschung20249270Google Scholar
  9. Lauterborn, R., 1906. Demostrationen aus der Fauna des Oberreheins und seiner Umgebung. Verhandlungen der Deutschen zoologischen Gesellschaft 265–268Google Scholar
  10. Marcus, E., 1929. Tardigrada. In Bronns, H. G. (ed.), Klassen und Ordnungen des Tierreichs. Section 4, Part 3, Vol. 5, Akademische Verlagsgesellschaft, Leipzig: 1–608Google Scholar
  11. Murray, J. 1907aThe encystment of MacrobiotusZoologist11411Google Scholar
  12. Murray, J. 1907bEncystment of TardigradaTransactions of the Royal Society of Edinburgh45837854Google Scholar
  13. Pigòn, A., Weglarska, B. 1953The respiration of Tardigrada: a study in animal anabiosisBulletin of the Polish Academy of Sciences16972Google Scholar
  14. Rahm, G. 1925Die Cystenbildung bei den Wasserbewohnenden TardigradenInternationale Vereinigung für Theoretische und Angewandte Limnologie Verhandlungen3364371Google Scholar
  15. Rahm, G. 1926Die Trockenstarre (Anabiose) der MoostierweltBiolog Ctrbl.46452477Google Scholar
  16. Rahm, G. 1927TardigradaBiolog d Tiere Deutschland22156Google Scholar
  17. Rebecchi, L., Bertolani, R. 1994Maturative pattern of ovary and testis in eutardigrades of freshwater and terrestrial habitatsInvertebrate Reproduction and Development26107117Google Scholar
  18. Reukauf, E. W. 1912Ein neuer Wasserbär, Macrobiotus ferdinandi (Reukauf)Zoologischer Anzeiger39352353Google Scholar
  19. Richters, F., 1909. Tardigraden-Studien. Bericht der Senckenbergischen Naturfrorschender Gesellschaft in Frankfurt 28–45Google Scholar
  20. Richters, F., Krumbach, T. 1926TardigradaHandbunch der Zoologie3168Google Scholar
  21. Starck, C., Kristensen, R. M. 1999Tardigrades in the Soil of GreenlandBerichte zur Polarforschung3304463Google Scholar
  22. Szymańska, B. 1995Encystment in the tardigrade Dactylobiotus dispar (Murray, 1907) (Tardigrada: Eutardigrada). Part 1: Observation of leaving animals and structure of cystZoologica Poloniae4091102Google Scholar
  23. Thulin, G. 1911Beiträge zur Kenntnis der Tardigradenfauna SchwedensArchiv für Zoologi7160Google Scholar
  24. Thulin, G. 1928Über die Phylogenie und das System der TardigradenHereditas11207266Google Scholar
  25. Wenck, V. 1914Entwicklungsgeschichtliche Untersuchungen an Tardigraden (Macrobiotus lacustris Duj.)Zoologischen Jahrbüchern, Abteilung für Anatomie und Ontogenie der Tiere37492505Google Scholar
  26. Weglarska, B. 1957On the encystation in TardigradaZoologica Poloniae8315325Google Scholar
  27. Weglarska, B. 1970Hypsibius (Isohypsibius) smreczynskii spec. nov., a new species of fresh-water tardigradeZeszyty Naukowe Uniwersytetu Jagiellonskiego, Prace Zoologicnzne16107114Google Scholar
  28. Westh, P., Kristensen, R. M. 1992Ice formation in the freeze-tolerant eutardigrades Adorybiotus coronifer and Amphibolus nebulosus studied by differential scanning calorimetryPolar Biology12693699CrossRefGoogle Scholar
  29. Wright, J. C., Westh, P., Ramløv, H. 1992Cryptobiosis in TardigradaBiological Review67129Google Scholar

Copyright information

© Springer 2006

Authors and Affiliations

  • Roberto Guidetti
    • 1
  • Deborah Boschini
    • 1
  • Lorena Rebecchi
    • 1
  • Roberto Bertolani
    • 1
  1. 1.Department of Animal BiologyUniversity of Modena and Reggio EmiliaModenaItaly

Personalised recommendations