Biological Institute ZRC SAZU

Ljubljana, Slovenia

Biological Institute ZRC SAZU

Ljubljana, Slovenia
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Malek-Hosseini M.J.,Biological Institute ZRC SAZU | Zamani A.,University of Tehran
Subterranean Biology | Year: 2017

Understanding subterranean biodiversity is important, yet vast regions of the world remain poorly explored. Here, we provide the first step towards cataloguing the subterranean arthropods of Iran. After review and analysis of the available literature and the examination of samples collected by us from Iranian caves, we listed 89 cavernicolous species (from 42 caves and 5 karstic springs) belonging to four arthropod subphyla: Chelicerata (1 class, 4 orders, 36 species), Crustacea (2 classes, 3 orders, 15 species), Hexapoda (2 classes, 5 orders, 34 species) and Myriapoda (2 classes, 3 orders, 4 species). © Mohammad J. Malek-Hosseini, Alireza Zamani.

Xu X.,Hubei University | Liu F.,Hubei University | Chen J.,Hubei University | Li D.,Hubei University | And 4 more authors.
Zoological Journal of the Linnean Society | Year: 2015

Species delimitation is difficult for taxa in which the morphological characters are poorly known because of the rarity of adult morphs or sexes, and in cryptic species. In primitively segmented spiders, family Liphistiidae, males are often unknown, and female genital morphology - usually species-specific in spiders - exhibits considerable intraspecific variation. Here, we report on an integrative taxonomic study of the liphistiid genus GanthelaXu & Kuntner, 2015, endemic to south-east China, where males are only available for two of the seven morphological species (two known and five undescribed). We obtained DNA barcodes (cytochromec oxidase subunitI gene, COI) for 51 newly collected specimens of six morphological species and analysed them using five species-delimitation methods: DNA barcoding gap, species delimitation plugin [P ID(Liberal)], automatic barcode gap discovery (ABGD), generalized mixed Yule-coalescent model (GMYC), and statistical parsimony (SP). Whereas the first three agreed with the morphology, GMYC and SP indicate several additional species. We used the consensus results to delimit and diagnose six Ganthela species, which in addition to the type species Ganthela yundingensisXu, 2015, completes the revision of the genus. Although multi-locus phylogenetic approaches may be needed for complex taxonomic delimitations, our results indicate that even single-locus analyses based on the COI barcodes, if integrated with morphological and geographical data, may provide sufficiently reliable species delimitation. © 2015 The Linnean Society of London.

Xu X.,Hubei University | Liu F.,Hubei University | Cheng R.-C.,Biological Institute ZRC SAZU | Chen J.,Hubei University | And 11 more authors.
Proceedings of the Royal Society B: Biological Sciences | Year: 2015

Living fossils are lineages that have retained plesiomorphic traits through long time periods. It is expected that such lineages have both originated and diversified long ago. Such expectations have recently been challenged in some textbook examples of living fossils, notably in extant cycads and coelacanths. Using a phylogenetic approach, we tested the patterns of the origin and diversification of liphistiid spiders, a clade of spiders considered to be living fossils due to their retention of arachnid plesiomorphies and their exclusive grouping in Mesothelae, an ancient clade sister to all modern spiders. Facilitated by original sampling throughout their Asian range, we here provide the phylogenetic framework necessary for reconstructing liphistiid biogeographic history. All phylogenetic analyses support the monophyly of Liphistiidae and of eight genera. As the fossil evidence supports a Carboniferous Euramerican origin of Mesothelae, our dating analyses postulate a long eastward over-land dispersal towards the Asian origin of Liphistiidae during the Palaeogene (39–58 Ma). Contrary to expectations, diversification within extant liphistiid genera is relatively recent, in the Neogene and Late Palaeogene (4–24Ma). While no over-water dispersal events are needed to explain their evolutionary history, the history of liphistiid spiders has the potential to play prominently in vicariant biogeographic studies. © 2015 Royal Society of London. All rights reserved.

Xu X.,Hunan Normal University | Xu X.,Hubei University | Liu F.,Hubei University | Chen J.,Hubei University | And 7 more authors.
Journal of Biogeography | Year: 2016

Aim: Phylogeographical research in the East Asian continent and islands (East Asian Margins, or EAM) suggests predominant Pleistocene over-water dispersal events from continent to islands, but more ancient biogeographical patterns in EAM remain obscure. We explored biogeographical histories and population genetic structures of the primitively segmented spiders, Heptathela and Ryuthela (Liphistiidae), broadly codistributed across EAM islands. To test competing biogeographical hypotheses, we looked for geohistoric events that may have shaped their distributional patterns. Location: Kyushu and Ryukyus. Methods: We sampled 17 Heptathela and Ryuthela species on 10 out of 12 EAM islands and sequenced fragments of two mitochondrial and three nuclear genes. We performed phylogenetic, network, time-calibrated and biogeographical analyses to identify lineages, estimate their divergence times, and reconstruct ancestral ranges. We also assessed genetic diversity and historic demography of each lineage. Results: Phylogenetic origin of Heptathela + Ryuthela is estimated at 26.6-18.4 Ma (95% HPD) when EAM islands became separated from the continent. The crown ages of Heptathela (18.0-10.7 Ma) and Ryuthela (17.8-8.7 Ma) coincide with the formation of Japan Sea and Okinawa Trough respectively. A split within Ryuthela (13.9-6.0 Ma) coincides with the opening of the Kerama Gap, but a split within Heptathela (18.0-10.7 Ma) pre-dates the formation of the Tokara Gap. Speciation within Heptathela and Ryuthela is relatively recent (6.0-0.3 Ma). Population genetic and demographic results suggest interrupted gene flow within and among islands, with most species exhibiting stable past populations. Main conclusions: Historic biogeographical reconstructions strongly suggest predominant vicariant origins of EAM island liphistiids. Restricted gene flow following barrier formation is the dominant speciation force in these spiders. As they never seem to cross bodies of water, their past range expansion, successive fragmentation of EAM, and other vicariant events, must have shaped the detected genetic boundaries among and within islands. © 2016 John Wiley & Sons Ltd.

Agnarsson I.,University of Vermont | Agnarsson I.,Smithsonian Institution | LeQuier S.M.,University of Vermont | Kuntner M.,Smithsonian Institution | And 4 more authors.
ZooKeys | Year: 2016

The Caribbean islands harbor rich biodiversity with high levels of single island endemism. Stretches of ocean between islands represent significant barriers to gene-flow. Yet some native species are widespread, indicating dispersal across oceans, even in wingless organisms like spiders. Argiope argentata (Fabricius, 1775) is a large, charismatic, and widespread species of orb-weaving spider ranging from the United States to Argentina and is well known to balloon. Here we explore the phylogeography of A. argentata in the Caribbean as a part of the multi-lineage CarBio project, through mtDNA haplotype and multi-locus phylogenetic analyses. The history of the Argiope argentata lineage in the Caribbean goes back 3-5 million years and is characterized by multiple dispersal events and isolation-by-distance. We find a highly genetically distinct lineage on Cuba which we describe as Argiope butchko sp. n. While the argentata lineage seems to readily balloon shorter distances, stretches of ocean still act as filters for among-island gene-flow as evidenced by distinct haplotypes on the more isolated islands, high FST values, and strong correlation between intraspecific (but not interspecific) genetic and geographic distances. The new species described here is clearly genetically diagnosable, but morphologically cryptic, at least with reference to the genitalia that typically diagnose spider species. Our results are consistent with the intermediate dispersal model suggesting that good dispersers, such as our study species, limit the effect of oceanic barriers and thus diversification and endemism. © Ingi Agnarsson et al.

PubMed | Smithsonian Institution, Lewis And Clark College, Biological Institute ZRC SAZU and University of Vermont
Type: | Journal: ZooKeys | Year: 2016

The Caribbean islands harbor rich biodiversity with high levels of single island endemism. Stretches of ocean between islands represent significant barriers to gene-flow. Yet some native species are widespread, indicating dispersal across oceans, even in wingless organisms like spiders.

Kralj-Fiser S.,Biological Institute ZRC SAZU | Kralj-Fiser S.,University of Primorska | Candek K.,Biological Institute ZRC SAZU | Lokovsek T.,Biological Institute ZRC SAZU | And 6 more authors.
Animal Behaviour | Year: 2016

Intersexual agonistic encounters prior to mating are thought to result from the 'spillover' of the advantages of a voracious personality within a foraging context that is maladaptive in a mating context. We tested this idea by examining the repeatability and cross-context consistency of aggressive behaviours associated with foraging and mating in the raft spider, Dolomedes fimbriatus, in which some, highly voracious females reportedly kill approaching males and thus remain unmated. We failed to find support for a maladaptive spillover of voracious female personality. While females exhibited consistent interindividual differences in voracity towards prey, voracity did not correlate with female aggressiveness towards males. Instead, we show that female D. fimbriatus adjusted their tendency to attack courting males according to their size relative to the male. Females commonly attacked males during or after copulation, but sexual cannibalism depended on relative mate size difference, with mating success tending to be compromised in females with lower body weight. © 2015 The Association for the Study of Animal Behaviour.

Cheng R.-C.,Biological Institute ZRC SAZU | Kuntner M.,Biological Institute ZRC SAZU | Kuntner M.,Hubei University | Kuntner M.,Smithsonian Institution
Evolutionary Biology | Year: 2015

Many organisms are sexually dimorphic, reflecting sex-specific selection pressures. But although sexual dimorphism may consist of different variables from size to shape and physiology, most research emphasizes a single aspect of sexual dimorphism, notably size, without specifying its components and their relationship. Among terrestrial animals, spiders exhibit most extreme sex-specific differences in size and abdominal shape, and therefore represent ideal models to address this question. Here, we dissect sexual dimorphism in spiders at two phylogenetic hierarchical levels. At the species level, we employ comparative phylogenetic tests to explore the association between sexual shape dimorphism (SShD) and sexual size dimorphism (SSD) in the orbweb clade Argiopinae. At the genus level, we then explore such patterns on a phylogeny of orb weavers (Araneoidea). Female argiopines had more diverse abdominal morphotypes than the males and the abdominal shape evolution was only poorly correlated between the sexes. Phylogenetic and comparative data suggested that evolution of SShD in argiopines was related to geographic history, but that sexually shape monomorphic cases arose through selection for male size, perhaps acting against fecundity selection. While in argiopines there was no clear association between SShD and SSD, we detected a significant correlation in all orb weavers at the genus level. The shape and the size components of sexual dimorphism may thus respond independently to selection pressures, but at certain phylogenetic levels SSD may be a prerequisite for SShD. Research on other animal groups is needed to establish whether the here detected patterns on spiders are general. © 2015, Springer Science+Business Media New York.

PubMed | University of the Free State and Biological Institute ZRC SAZU
Type: | Journal: Scientific reports | Year: 2016

Though not uncommon in other animals, heterospecific mating is rarely reported in arachnids. We investigated sexual interactions among four closely related and syntopical African golden orbweb spiders, Nephila inaurata, N. fenestrata, N. komaci, and N. senegalensis. In two South African localities, female webs were often inhabited by heterospecific males that sometimes outnumbered conspecifics. Species association of males with females was random in nature. In subsequent laboratory choice experiments, N. inaurata males chose heterospecific females in 30% of trials. We also observed natural mating interactions between N. inaurata males and N. komaci females, and between N. komaci males and N. inaurata females in laboratory experiments. While heterospecific mating in the laboratory never produced offspring, conspecific mating did. We discuss potential ecological and evolutionary consequences of heterospecific mating interactions in Nephila that may be particularly costly to the rarer species.

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