A cytogenetical study on two ground spider species (gnaphosidae: drassodes) from Nevşehir district

Abstract

In this study, we describe a chromosomal analysis of Drassodes bifidus and Drassodes serratichelis using a classical Giemsa staining method. We collected specimens from different populations in Nevşehir and used totally fourteen male spiders. The two Drassodes species had karyotypes comprising 10 pairs of autosomes plus sex chromosomes which were X1X20 (♂) type. All chromosomes including sex chromosomes were telocentric and relative lengths of autosomal pairs were decreased gradually in size. All male meiosis was chiasmate and during the first meiotic division stages, 10 autosomal bivalents and generally one chiasma per bivalent (rarely two chiasmata) were obtained, the types of chiasmata were proximal, interstitial and terminal. In second meiotic division, two types of nuclei were showed as n=12 and n=10 chromosomes. Considering our results and previously obtained data in other ground spider species, the conventional staining provide important chromosome markers for karyotype evolution in gnaphosids and chromosome structure studies.