0000000000134301
AUTHOR
Axel L. Schönhofer
Tracking the ice: Subterranean harvestmen distribution matches ancient glacier margins
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…
Biological richness of a large urban cemetery in Berlin. Results of a multi-taxon approach.
Abstract Background Urban green spaces can harbor a considerable species richness of plants and animals. A few studies on single species groups indicate important habitat functions of cemeteries, but this land use type is clearly understudied compared to parks. Such data are important as they (i) illustrate habitat functions of a specific, but ubiquitous urban land-use type and (ii) may serve as a basis for management approaches. New information We sampled different groups of plants and animals in the Weißensee Jewish Cemetery in Berlin (WJC) which is one of the largest Jewish cemeteries in Europe. With a total of 608 species of plants and animals, this first multi-taxon survey revealed a c…
Molecular phylogeny, biogeographic history, and evolution of cave-dwelling taxa in the European harvestman genusIschyropsalis(Opiliones: Dyspnoi)
Abstract We estimated a multigenic molecular phylogeny and reconstructed biogeographic history for the European harvestman genus Ischyropsalis C.L. Koch 1839 (Dyspnoi). To reconstruct historical biogeographic patterns we conducted an algorithmic VIP analysis which revealed patterns consistent with a vicariance-dominated history. The existing morphology-based systematic framework for Ischyropsalis is mostly inconsistent with molecular phylogenetic results, and a new informal system is established that recognizes three main clades and several sub-clades. Species-level analyses revealed two non-monophyletic species (I. pyrenaea Simon 1872 and I. luteipes Simon 1872); subspecies of I. pyrenaea …
Molecular phylogeny of the spider family Sparassidae with focus on the genus Eusparassus and notes on the RTA-clade and ‘Laterigradae’
The phylogeny of the spider family Sparassidae is comprehensively investigated using four molecular markers (mitochondrial COI and 16S; nuclear H3 and 28S). Sparassidae was recovered as monophyletic and as most basal group within the RTA-clade. The higher-level clade Dionycha was not but monophyly of RTA-clade was supported. No affiliation of Sparassidae to other members of the 'Laterigradae' (Philodromidae, Selenopidae and Thomisidae) was observed, and the crab-like posture of this group assumed a result of convergent evolution. Only Philodromidae and Selenopidae were found members of a supported clade, but together with Salticidae and Corinnidae, while Thomisidae was nested within the hig…
Revision of the genus Trogulus Latreille: the Trogulus coriziformis species-group of the western Mediterranean (Opiliones:Trogulidae)
Within the well researched European fauna of harvestmen, the genus Trogulus Latreille exhibits unexpectedly high cryptic diversity. The species’ uniform morphology hinders an exclusively morphological approach to their systematics and taxonomy, and a preliminary molecular study estimated the number of species to be three times higher than currently known. The current study focuses on a clearly defined species-group within Trogulus, combining molecular (~1700 bp 28S rRNA and the cytochrome b gene), distributional, morphometric and morphological data. Relationships are reconstructed using Bayesian inference, maximum parsimony and maximum likelihood and this information is subsequently used t…
Gluing the ‘unwettable’: soil-dwelling harvestmen use viscoelastic fluids for capturing springtails
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…
The Leiobunum rupestre species group: resolving the taxonomy of four widespread European taxa (Opiliones: Sclerosomatidae)
Within the central European opilionid fauna the widely used species names Leiobunum rupestre Herbst, 1799 and Leiobunum tisciae Avram, 1968 pose taxonomic and distributional problems. In addition, Nelima apenninica Martens, 1969 is close to L. tisciae in terms of external and genital morphology, but is specifically distinct. While coxal denticulation is largely lacking in N. apenninica, the validity of the genus Nelima Roewer, 1910 is questioned again. In addition, Leiobunum subalpinum Komposch, 1998, a recently described novelty from the eastern Alps, is closely related to L. rupestre. The four species are combined as the morphologically defined Leiobunum rupestre species group. Except for…
Molecular phylogeny of the harvestmen genus Sabacon (Arachnida: Opiliones: Dyspnoi) reveals multiple Eocene–Oligocene intercontinental dispersal events in the Holarctic
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…
The evolution of pedipalps and glandular hairs as predatory devices in harvestmen (Arachnida, Opiliones)
Pedipalps are the most versatile appendages of arachnids. They can be equipped with spines (Amblypygi), chelae (Scorpiones), or adhesive pads (Solifugae), all of which are modifications to grasp and handle fast-moving prey. Harvestmen (Opiliones) show a high diversity of pedipalpal morphologies. Some are obviously related to prey capture, like the enlargement and heavy spination of Laniatores pedipalps. Many Dyspnoi, by contrast, exhibit thin, thread-like pedipalps that are covered with complex glandular setae (clavate setae). These extrude viscoelastic glue that is used to immobilize prey items. Comparable setae (plumose setae) have previously been found in representatives of both Eupnoi a…
An unidentified harvestman Leiobunum sp. alarmingly invading Europe (Arachnida: Opiliones)
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…
Mittel- und nordeuropäische Weberknechte aus dem Senckenberg Museum Frankfurt (Arachnida: Opiliones)
Central and North European harvestmen from the Senckenberg Museum Frankfurt (Arachnida: Opiliones). About 1100 individuals belonging to 32 opilionid species (300 series), mainly of German origin, were identified based on material provided by, and stored at, the Senckenberg Museum, Frankfurt (Main). A list of all species with habitat information is included. Comments on two remarkable species (Oligolophus hanseni, Odiellus spinosus) are given. The comments include the importance of some series as reference material from MARTENS (1978), additions to regional faunas and the expansion of the known distribution of some thermophilous species.
Nemastoma bidentatum (Arachnida: Opiliones: Nemastomatidae): neu für Deutschland und die Tschechische Republik
Nemastoma bidentatum (Arachnida: Opiliones: Nemastomatidae): first records for Germany and the Czech Republic. N. bidentatum Roewer, 1914 was found at two places in Germany: first on the island "Harriersand" in the Weser river (Lower Saxony), second on the banks of the river Elbe in the Elbsandsteingebirge (Saxony). Adjacent to the latter locality an occurrence in the Czech Republic could be located close to the German/Czech border in the floodplain of the river Elbe as well. These records are the first for Germany and the Czech Republic. They enlarge the distribution area of N. bidentatum remarkably in both a northern and a western direction. The two populations show conspicuous difference…
Hidden Mediterranean diversity: Assessing species taxa by molecular phylogeny within the opilionid family Trogulidae (Arachnida, Opiliones)
This is the first comprehensive study to evaluate the relationships between the western palearctic harvestman families Dicranolasmatidae, Trogulidae and Nemastomatidae with focus on the phylogeny and systematics of Trogulidae, using combined sequence data of the nuclear 28S rRNA and the mitochondrial cytochrome b gene. Bayesian analysis and Maximum parsimony do not reliably resolve Dicranolasma as distinct family but place it on a similar phylogenetic level as several lineages of Trogulidae. Nemastomatidae and Trogulidae turned out to be monophyletic, as did genera Anelasmocephalus and Trogulus within the Trogulidae. The genera Calathocratus, Platybessobius and Trogulocratus each appeared p…
Revision of the genusTrogulus Latreille: the morphologically divergentTrogulus torosusspecies-group of the Balkan Peninsula (Opiliones: Dyspnoi: Trogulidae)
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…
On the identity of Ischyropsalis dentipalpis Canestrini, 1872 and description of Ischyropsalis lithoclasica sp. n. (Opiliones: Ischyropsalididae)
Ischyropsalis dentipalpis Canestrini, 1872 is re-defined, and a neotype from the type locality in the Aosta Valley, Italy, is assigned. I. helvetica Roewer, 1916 (sensu Martens 1978) is shown to be conspecific and therefore is synonymised with I. dentipalpis. A population from Bergamo Province, Italy, formerly assigned to I. dentipalpis (sensu Martens 1978), is here regarded as a different species and described under the name Ischyropsalis lithoclasica sp. n. Discrimination of males is possible by genital characters and by the shape of the cheliceral and pedipalpal apophyses. Females are distinguished by peculiarities of cheliceral spination. The distribution of I. lithoclasica n. sp. is al…
On Harvestmen from the Soutpansberg, South Africa, with Description of a New Species ofMonomontia(Arachnida: Opiliones)
The harvestman fauna of the Western Soutpansberg was investigated during two collecting trips. Comments are made on the variability, ecology and remarkable morphological features of the collected material. Characters are displayed and differences to type series are highlighted. Monomontia neglecta sp. n. is described from material housed at the Natal Museum. Metabiantes leighi Pocock, 1902 is recorded for the first time for the Soutpansberg area. A species list is provided, listing all known records and the state of endemism. The relative species richness of the eastern Soutpansberg is discussed in comparison with the western area.