Karyotype features based on diploid number and sex chromosome system of Steatoda grossa (Araneae: Theridiidae) from Turkey

Abstract

In this study, karyotypic investigation of Steatoda grossa belonging to the family, Theridiidae was carried out to contribute cytogenetic relationships of the family. A standard air-drying method was used to obtain chromosome slides including three main steps as hypotonisation, fixation and staining. As a result, the diploid number and sex chromosome system was determined as 2n♂=22 (X1X2). All chromosomes were telocentric and gradually decreased in size. Sex chromosomes were positively heteropycnotic in the stages of meiosis I, and isopycnotic in meiosis II. The results showed the similarity with the previous investigations obtained from different populations.