Ontogeny, variation, and synonymy in North American Cybaeus spiders (Araneae: Cybaeidae)

Abstract

AbstractOntogeny, interspecific homogeneity, and intraspecific variability of female genitalic and other characters of North American Cybaeus L. Koch spiders are described and used to resolve taxonomic problems in the genus. Ontogenetic changes in spermathecal duct morphology occur as females mature and age. Three distinct ontogenetic stages are described: pre-epigynum/pre-vulva, subadult / teneral adult, and mature adult. Concordant with aspects of sexual selection theory, closely related females may be morphologically indistinguishable. Many Cybaeus species exhibit a wide range of body size. Within single species, ontogenetic stages and outlier size classes have been described as separate species. Species with similar females have been lumped under one name. Based on this, 10 new synonyms are proposed for North American Cybaeus: C. adenoides Schenkel = C. grizzlyi Schenkel; C. chaudius Exline and C. hatchi Exline = C. shoshoneus Chamberlin and Ivie; C. exlineae Chamberlin and Ivie = C. bulbosus Exline; C. hystrix Chamberlin and Ivie = C. cribelloides Chamberlin and Ivie; C. janus Chamberlin and Ivie = C. eutypus Chamberlin and Ivie; C. marinensis Chamberlin and Ivie and C. angelus Chamberlin and Ivie = C. consocius Chamberlin and Ivie; and C. olympiae Exline and C. tius Chamberlin and Ivie = C. reticulatus Simon. In addition, four old synonyms are rejected: C. grizzlyi Schenkel and C. adenoides Schenkel ≠ C. adenes Chamberlin and Ivie; C. patritus Bishop and Crosby and C. silicis Barrows ≠ C. giganteus Banks.