CYTOGENETIC HETEROGENEITY IN COMMON HAPLOGYNE SPIDERS FROM ARGENTINA (ARACHNIDA, ARANEAE)

Abstract

The spermatogenesis of four species of haplogyne spiders from Argentina is analyzed. Dysdera crocota (Dysderidae) (n = 5 X0) has holokinetic chromosomes, achiasmatic male meiosis and a post-reductional division of the sex chromosome. Ariadna boesenbergii (Segestriidae) (n = 4 X0) also possesses holokinetic chromosomes, but meiosis is chiasmatic and the X chromosome divides pre-reductionally. Kukulcania hibernalis (Filistatidae) (n = 11 X1X20) and Scytodes globula (Scytodidae) (n = 6 X0) have metacentric and submetacentric chromosomes, chiasmatic meiosis and the sex chromosomes divide pre-reductionally. Kukulcania hibernalis possesses a bimodal karyotype and a particular chromatin coiling during prophase I, while Scytodes globula has striking proximal localization of chiasmata. These results show that Haplogynae present high cytogenetic heterogeneity: species with holokinetic chromosomes as well as species with monocentric chromosomes (metacentric and submetacentric), and species with low diploid numbers, achiasmatic meiosis and proximal chiasma localization.