Karyological data and meiosis of Drassyllus praeficus (L. Koch, 1866) (Gnaphosidae) and Thanatus imbecillus (L. Koch, 1878) (Philodromidae) from Turkey

In this study, karyotypic and cytogenetic characteristics of Drassyllus praeficus (L. Koch, 1866) and Thanatus imbecillus (L. Koch, 1878) were investigated for the first time by examining mitotic and meiotic chromosomes obtained from gonad cells. The number and the sex chromosome system of D. praeficus and T imbecillus males was 2n = 22 (X(1)X(2)0) and 2n = 28 (X(1)X(2)0), respectively. D. praeficus had 10 autosomal bivalents and 2 univalent sex chromosomes, and T imbecillus had 13 autosomal bivalents and 2 univalent sex chromosomes during the first meiotic prophase and metaphase. Both species possessed acrocentric chromosomes in their karyotypes.