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

References (2)

1. Gnaphosidae, Drassyllus D. pumilus (C.L. Koch 1839) D. praeficus (L. Koch, 1866) 22; a 22; a X 1 X 2 X 1 X 2 Kumbıçak et al., 2009
2. This study Philodromidae, Thanatus T. formicinus (Clerck, 1757) T. meronensis Levy, 1977 T. imbecillus (L. Koch, 1878) 28; a 28; a 28; a X 1 X 2 X 1 X 2 X 1 X 2 Hackman, 1948 Gorlova et al., 1997 This study 2012), but only 1 Drassyllus species has been investigated cytogenetically (Table 2). The first chromosomal data of the genus Drassyllus were provided by Kumbıçak et al. (2009), who reported 2n♂ = 22 in Drassyllus pumilus (C. L. Koch, 1839). Their data are compatible with our results on D. praeficus. In the majority of gnaphosids studied previously, the karyotypes consist of acrocentric chromosomes and the sex chromosome system is X 1 X 2 0. The only exceptions are 2 unidentified Drassodes species and Urozelotes rusticus reported by Srivastava and Shukla (1986), which have an X0 system. According to our results, D. praeficus had acrocentric chromosomes and an X 1 X 2 0 sex chromosome system. It seems that the chromosome number and sex chromosome system are relatively conservative in the family Gnaphosidae. Despite the high diversity of philodromids, they are poorly known from the cytogenetic point of view. As of today, 15 species have been examined (Araujo et al., 2012). Diploid chromosome numbers in Thanatus meronensis Levy, 1977 and Thanatus formicinus (Clerck, 1757) are 2n♂ = 28 and the sex chromosome is X 1 X 2 0 (Hackman, 1948; Gorlova et al., 1997). In addition to this, the majority of species belonging to the genus Philodromus Walckenaer, 1826 has 2n♂ = 28 (X 1 X 2 0). Our result for the diploid chromosome number of T. imbecillus was 2n = 28, which is compatible with the results of both Thanatus species studied so far (Hackman, 1948; Gorlova et al., 1997). Moreover, all 3 species exhibit similar karyotypes with the acrocentric chromosomes and the same sex chromosome system. By itself, the current knowledge is not sufficient to make comparisons about the cytogenetic characteristics of the genus Thanatus; therefore, new studies are needed. Acknowledgments We are grateful to Assist. Prof. Dr. Recep Kara and Assist. Prof. Dr. Tülay Ezer (Niğde University, Arts and Science Faculty, Biology Department) and to the Scientific and Technological Research Council of Turkey (TÜBİTAK, Project Number: 210T033) for providing support and equipment for taking photographs. We are also thankful to our anonymous reviewers for their valua