, Volume 558, Issue 1, pp 33–40 | Cite as

Phenotypic Variations in the Life History of Two Clones of Macrobiotus richtersi (Eutardigrada, Macrobiotidae)

  • Tiziana Altiero
  • Lorena Rebecchi
  • Roberto Bertolani


A comparative study of life history traits of two clones (CDMr01 and CDMr02) of a triploid thelytokous apomictic population of the eutardigrade Macrobiotus  richtersi has been carried out. Both clones were reared under the same lab conditions: temperature of 14 °C, photoperiod of 12 h/12 h (L/D), and nematodes ad libitum as food. Statistical analysis of the life history traits considered has indicated interclonal variability. The two clones were significantly different in the number of eggs per clutch (fertility), number of eggs laid per female per life span (fecundity), hatching percentage of eggs and hatching time. Similarities between clones have been observed with regard to life span, total number of ovipositions per life span, and age at first oviposition. In addition, significant differences in hatching time, with eggs hatched over a long period, were found within each clone. Interclonal variability in life history traits indicated the effects of genetic factors, whereas intraclonal variability reflected the effects of environmental factors. The evolutionary and adaptive significance of the life history phenotypic variations is discussed.


Macrobiotus richtersi life history clones clonal variability Tardigrada apomixis 


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Copyright information

© Springer 2006

Authors and Affiliations

  • Tiziana Altiero
    • 1
  • Lorena Rebecchi
    • 1
  • Roberto Bertolani
    • 1
  1. 1.Department of Animal BiologyUniversity of Modena and Reggio EmiliaModenaItaly

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