Search results for "Opiliones"
showing 10 items of 32 documents
An unidentified harvestman Leiobunum sp. alarmingly invading Europe (Arachnida: Opiliones)
2007
Etwa seit dem Jahr 2000 breitet sich eine bisher nicht identifizierte Art der Gattung Leiobunum C. L. Koch, 1839 schnell in Mitteleuropa aus. Nachweise ab dem Jahr 2004 sind aus den Niederlanden (wahrscheinlich dem Land des ersten Auftretens in Europa), Deutschland, Österreich und der Schweiz bekannt. Die wahrscheinlich eingeschleppte Art besiedelt bisher lediglich Wände von Gebäuden und seltener felsähnliche Biotope in Wäldern. Adulte Individuen ruhen tagsüber selten einzeln oder in eng geklumpten Gruppen aus Dutzenden bis Hunderten von Individuen an leicht abgedunkelten Stellen in Mauerwinkeln, an glatten Hauswänden und überhängenden Dachtraufen. Jungtiere leben am Boden. Diese Art verfüg…
Tracking the ice: Subterranean harvestmen distribution matches ancient glacier margins
2019
Biogeographic studies often underline the role of glacial dynamism during Pleistocene (1.806-0.011 Mya) in shaping the distribution of subterranean species. Accordingly, it is presumed that present-day distribution of most specialized cold-adapted (cryophilic) cave-dwelling species should bear the signatures of past climatic events. To test this idea, we modelled the distribution of specialized cold-adapted subterranean alpine harvestmen (Arachnida: Opiliones: Ischyropsalididae: Ischyropsalis). We found that the distance from the glacier margins during Last Glacial Maximum (LGM; about 22,000 years ago) was the most important predictor of their present-day distribution. In particular, the pe…
Sensory biology of Phalangida harvestmen (Arachnida, Opiliones): a review, with new morphological data on 18 species
2009
1463-6395 10.1111/j.1463-6395.2008.00341.x; Willemart, R. H., Farine, J.-P. and Gnaspini, P. 2008. Sensory biology of Phalangida harvestmen (Arachnida, Opiliones): a review, with new morphological data on 18 species. 2014Acta Zoologica (Stockholm) 90: 2092013227 Phalangida includes three of the four suborders of Opiliones (Arachnida): Eupnoi, Dyspnoi and Laniatores. We review the literature on the sensory structures and capabilities of Phalangida, provide new morphological data for 18 species and discuss the 11 sensory structures that have been described in the group. Based on the published data encompassing both behaviour and morphology, three conclusions are apparent: (1) species of Phala…
Molecular phylogeny of the harvestmen genus Sabacon (Arachnida: Opiliones: Dyspnoi) reveals multiple Eocene–Oligocene intercontinental dispersal even…
2012
Abstract We investigated the phylogeny and biogeographic history of the Holarctic harvestmen genus Sabacon , which shows an intercontinental disjunct distribution and is presumed to be a relatively old taxon. Molecular phylogenetic relationships of Sabacon were estimated using multiple gene regions and Bayesian inference for a comprehensive Sabacon sample. Molecular clock analyses, using relaxed clock models implemented in BEAST, are applied to date divergence events. Biogeographic scenarios utilizing S-DIVA and Lagrange C++ are reconstructed over sets of Bayesian trees, allowing for the incorporation of phylogenetic uncertainty and quantification of alternative reconstructions over time. F…
Revision of the genusTrogulus Latreille: the morphologically divergentTrogulus torosusspecies-group of the Balkan Peninsula (Opiliones: Dyspnoi: Trog…
2013
Within the species-rich European harvestman genus Trogulus Latreille, 1802, the Balkan Trogulus torosus species-group as defined by Schonhofer and Martens is revised. The group is remarkable because it includes the world's largest Opiliones species, Trogulus torosus Simon, 1885, and Trogulus ozimeci sp. nov. is the first member of the family showing obvious adaption to subterranean life. According to nuclear 28S and mitochondrial cytochrome b gene data, the T. torosus species-group and the Trogulus hirtus species-group form a monophyletic unit. Only the former is treated here as a paraphyletic group. Despite this paraphyly, the T. torosus species-group members share a number of morphologica…
Feinstruktur der Cheliceren-Dr�se von Nemastoma dentigerum Canestrini (Opiliones, Nemastomatidae)
1973
1. Nemastoma dentigerum Canestrini besitzt als sekundares mannliches Geschlechtsmerkmal eine Apophyse auf dem ersten Chelicerenglied, die eine Druse enthalt. 2. Die einzelnen Drusenzellen schliesen sich jeweils zu Dreiergruppen zusammen, deren distales Ende immer von 3 Hullzellen umfast wird. Diese 6 Zellen bilden eine funktionelle Einheit innerhalb des komplexen Drusenorgans. Jede Drusenzelle gliedert sich in 3 Abschnitte: 1. in den basalen kernhaltigen Teil, 2. in den mittleren sehr langen Drusenzellschlauch und 3. in den distalen Kopf mit Mikrovilli-Becher. 3. An der Sekretion beteiligen sich 2 Zelltypen: die 3 Drusenzellen und die innere Hullzelle (H1). Das Sekret beider Zelltypen gelan…
Two new species of the genus emNemaspela/em Šilhavý from caves in Georgia (Opiliones: Nemastomatidae).
2021
Two highly specialized endemic troglobiotic harvestman species of the genus Nemaspela Šilhavý, 1966 are described. N. melouri sp. nov. from Melouri Cave and N. prometheus sp. nov. from Prometheus Cave (Sataplia-Tskaltubo karst massif, Imereti region, western Georgia), respectively. Despite the fact that the entrances of the caves are positioned only 2.5 km apart, the new taxa differ from each other distinctly by presence vs. absence of male cheliceral apophysis, which is lacking in the second species. A key to the Caucasian species of the genus is provided. Relationships of Nemaspela species within the genus and with hypothetical epigean ancestors are discussed.
The Centetostoma scabriculum complex—a group of three cryptic species (Arachnida: Opiliones: Nemastomatidae)
2011
Nemastoma scabriculum Simon, 1879 turned out to be a group of three closely related species of the Pyrenees in SW Europe (France and Spain). Though the species are similar in general habit they can easily be recognized by external morphology (structure of the apophysis of male chelicerae) and male genital morphology (penial structure). For Nemastoma scabriculum Simon, 1879 sensu stricto a lectotype is designated. The synonymous Nemastoma ventalloi Mello-Leitao, 1936 is considered to be a distinct species and is re-described. The third species of the group is described as new, Centetostoma juberthiei sp. n. Though partly sympatric in their restricted Pyrenean area, the individual species are…
Gluing the ‘unwettable’: soil-dwelling harvestmen use viscoelastic fluids for capturing springtails
2014
Gluing can be a highly efficient mechanism of prey capture, as it should require less complex sensory–muscular feedback. Whereas it is well known in insects, this mechanism is much less studied in arachnids, except spiders. Soil-dwelling harvestmen (Opiliones, Nemastomatidae) bear drumstick-like glandular hairs (clavate setae) at their pedipalps, which were previously hypothesized to be sticky and used in prey capture. However, clear evidence for this was lacking to date. Using high-speed videography, we found that the harvestman Mitostoma chrysomelas was able to capture fast-moving springtails (Collembola) just by a slight touch of the pedipalp. Adhesion of single clavate setae increased p…
Redescription of the rare European harvestman Dicranopalpus brevipes Marcellino, 1970, based on first records from Sardinia (Arachnida: Opiliones)
2020
New records of the small, enigmatic harvestman Dicranopalpus brevipes are presented, the male is redescribed and the female is described for the first time. The species originates from Sicily, while the novel findings are from Sardinia, where it may have been introduced by man. Paedomorphic modifications such as reduced sexual dimorphism in colouration and pedipalpal morphology, regression of genital structures and shortening of the legs, appear to result from its ground-dwelling habits induced by xeric climatic conditions. Avoiding the dry and hot season, D. brevipes matures in autumn and winter and has completed its lifecycle in April. Additional information on phenology, ecology, distrib…