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Type: Article
Published: 2017-08-08
Page range: 140–150
Abstract views: 82
PDF downloaded: 2

A new species of Synotaxus and the first chromosomal study on Synotaxidae, presenting a rare XY sex chromosome system in spiders (Araneae, Araneoidea)

Setor de Biologia Geral, Instituto de Biociências, Universidade Federal de Mato Grosso do Sul, UFMS, Cidade Universitária, 79070-900, Campo Grande, Mato Grosso do Sul, Brazil
Instituto Butantan, Laboratório Especial de Coleções Zoológicas, Av. Vital Brasil 1500, CEP 05503-900, São Paulo, SP, Brazil
Setor de Biologia Geral, Instituto de Biociências, Universidade Federal de Mato Grosso do Sul, UFMS, Cidade Universitária, 79070-900, Campo Grande, Mato Grosso do Sul, Brazil
Araneae taxonomy Meiosis Cytogenetic Araneomorphae


Studies on spider chromosomes are very scarce, with 44 spider families without any cytogenetically analyzed species. Nevertheless, chromosomal characteristics can be useful for species delimitation, such as the sex chromosome system (SCS), which is particularly diverse in spiders. In this study, we describe Synotaxus jaraguari n. sp., based on male and female specimens from midwestern Brazil. This species has a distinctive “horn” in the male ocular area and seems related to a group of species that includes Synotaxus monocerus (Caporiacco, 1947), S. itabaiana Santos & Rheims, 2005 and S. siolli Santos & Rheims, 2005. We also present the first karyotype study on Synotaxidae. The mitotic and meiotic cells of S. jaraguari n. sp. revealed 2n♂ = 22 + XY and 2n♀ = 22 + XX telocentric chromosomes. This is the ninth spider species with a XY/XX SCS, which is extremely rare in the group.



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