Pholcus, males, sex chromosome behavior in second meiotic division, Giemsa staining A P. silvai, two sister metaphases II. Metaphase II containing the X chromosomes is composed of 13 chromosomes. Metaphase II containing the Y chromosome comprises 12 chromosomes B P. alticeps, two sister anaphases II. Chromosomes X1 and Y display positive heteropycnosis. The X chromosomes are associated. The Y chromosome is placed in the middle of the half plates C P. fuerteventurensis, two sister metaphases II. Plate containing the X chromosomes is incomplete (1 chromosome missing). Note the positive heteropycnosis of the sex chromosomes. Abbreviations: X1 = X1 chromosome, X2 = X2 chromosome, Y = Y chromosome. Scale bars: 10 μm.

 
 
  Part of: Král J, Ávila Herrera IM, Šťáhlavský F, Sadílek D, Pavelka J, Chatzaki M, Huber BA (2022) Karyotype differentiation and male meiosis in European clades of the spider genus Pholcus (Araneae, Pholcidae). Comparative Cytogenetics 16(4): 185-209. https://doi.org/10.3897/CompCytogen.v16i4.85059