title: Evolutionary morphology of the hemolymph vascular system of basal araneomorph spiders (Araneae: Araneomorphae).
abstract: The superfamily Austrochiloidea (Austrochilidae and Gradungulidae) take a pivotal position in araneomorph spider phylogeny. In this discussion crevice weaver spiders (Filistatidae) are of equal interest. Especially data from these phylogenetically uncertain yet basal off branching groups can enlighten our understanding on the evolution of organ systems. In the course of a survey on the evolutionary morphology of the circulatory system in spiders we therefore investigated the hemolymph vascular system in two austrochiloid and one filistatid species. Additionally some data on a hypochilid and a gradungulid species are included. Using up-to-date morphological methods, the vascular systems in these spiders are visualized three dimensionally. Ground pattern features of the circulatory systems in austrochiloid spiders are presented and the data discussed along recent lines of phylogenetic hypotheses. Special topics highlighted are the intraspecific variability of the origins of some prosomal arteries and the evolutionary correlation of respiratory and circulatory systems in spiders.
authors.affiliation: Allgemeine & Spezielle Zoologie, Institut für Biowissenschaften, Universität Rostock, Universitätsplatz 2, 18055 Rostock, Germany. Electronic address: kati.huckstorf@gmx.de.
authors.forename: Katarina
authors.initials: K
authors.lastname: Huckstorf
authors.affiliation: Zoologisches Institut und Museum, Universität Greifswald, Johann-Sebastian-Bach-Str. 11/12, 17489 Greifswald, Germany. Electronic address: michalik@uni-greifswald.de.
authors.forename: Peter
authors.initials: P
authors.lastname: Michalik
authors.affiliation: Museo Argentino de Ciencias Naturales, Buenos Aires C1405DJR, Argentina. Electronic address: ramirez@macn.gov.ar.
authors.forename: Martín
authors.initials: M
authors.lastname: Ramírez
authors.affiliation: Allgemeine & Spezielle Zoologie, Institut für Biowissenschaften, Universität Rostock, Universitätsplatz 2, 18055 Rostock, Germany. Electronic address: christian.wirkner@web.de.
authors.forename: Christian S
authors.initials: CS
authors.lastname: Wirkner
mesh_terms: D000818:Animals; D005075:Biological Evolution; D005260:Female; D006458:Hemolymph / Q000000981:diagnostic imaging; D013112:Spiders / Q000033:anatomy & histology*; D055114:X-Ray Microtomography
keywords: 3D-reconstruction; Austrochilidae; Circulatory system; Filistatidae; Gradungulidae; Heart; Hypochilidae; Micro computer tomography