, Volume 255, Issue 1, pp 225–230

Oogenesis in Macrotrachela quadricornifera (Rotifera, Bdelloidea)

I. Germarium eutely, karyotype and DNA content
  • Manuela Pagani
  • Claudia Ricci
  • Carlo Alberto Redi

DOI: 10.1007/BF00025843

Cite this article as:
Pagani, M., Ricci, C. & Redi, C.A. Hydrobiologia (1993) 255: 225. doi:10.1007/BF00025843


Bdelloids reproduce via obligate apomictic parthenogenesis. Oogenesis occurs through two subsequent equational divisions, with the extrusion of two polar bodies. Although the morphology of the bdelloid reproductive apparatus has been previously described, the eutely of the germarium has never been investigated. We studied oogenesis in Macrotrachela quadricornifera by assessing: (1) the constancy of oocyte number, (2) chromosome number and size, and (3) the DNA content of oocytes and blastomeres. Oocyte number at birth is constant and determines maximal fertility. We found a chromosome number of 5, in which two homologous pairs can be recognized. The genome size of the species is 0.75 picograms.

Key words

bdelloid rotifersoocyteskaryotypechromosomesDNA content

Copyright information

© Kluwer Academic Publishers 1993

Authors and Affiliations

  • Manuela Pagani
    • 1
  • Claudia Ricci
    • 2
  • Carlo Alberto Redi
    • 3
  1. 1.Dipartimento di BiologiaMilanoItaly
  2. 2.Dipartimento di Biologia AnimaleTorinoItaly
  3. 3.Dipartimento di Biologia Animale e Centro di Studio per l'Istochimica del C.N.R.PaviaItaly