Phylogeographic analysis of Pimoidae (Arachnida: Araneae) inferred from mitochondrial cytochrome c oxidase subunit I and nuclear 28S rRNA gene regions

Thirty-five new species of the spider genus Pimoa (Araneae, Pimoidae) from Pan-Himalaya

Thirty-five new species of the Pimoa Chamberlin & Ivie, 1943 are described from Pan-Himalaya: P.anning Zhang & Li, sp. nov. (♂♀), P.bomi Zhang & Li, sp. nov. (♂♀), P.cawarong Zhang & Li, sp. nov. (♀), P.daman Zhang & Li, sp. nov. (♀), P.danba Zhang & Li, sp. nov. (♀), P.deqen Zhang & Li, sp. nov. (♀), P.dongjiu Zhang & Li, sp. nov. (♂♀), P.guiqing Zhang & Li, sp. nov. (♀), P.gyaca Zhang & Li, sp. nov. (♀), P.gyara Zhang & Li, sp. nov. (♂♀), P.gyirong Zhang & Li, sp. nov. (♂♀), P.heishui Zhang & Li, sp. nov. (♂♀), P.jinchuan Zhang & Li, sp. nov. (♂♀), P.khaptad Zhang & Li, sp. nov. (♀), P.koshi Zhang & Li, sp. nov. (♀), P.lhatog Zhang & Li, sp. nov. (♀), P.mechi Zhang & Li, sp. nov. (♂♀), P.miandam Zhang & Li, sp. nov. (♂♀), P.miero Zhang & Li, sp. nov. (♂♀), P.mude Zhang & Li, sp. nov. (♀), P.muli Zhang & Li, sp. nov. (♂♀), P.naran Zhang & Li, sp. nov. (♀), P.ninglang Zhang & Li, sp. nov. (♀), P.nyalam Zhang & Li, sp. nov. (♂♀), P.phaplu Zhang & Li, sp. nov. (♂♀), P.putou Zhang & Li, sp. nov. (♀), P.rara Zhang & Li, sp. nov. (♀), P.sangri Zhang & Li, sp. nov. (♂♀), P.shigatse Zhang & Li, sp. nov. (♀), P.tengchong Zhang & Li, sp. nov. (♂♀), P.xiahe Zhang & Li, sp. nov. (♂♀), P.yejiei Zhang & Li, sp. nov. (♀), P.yele Zhang & Li, sp. nov. (♂♀), P.zayu Zhang & Li, sp. nov. (♂♀), P.zhigangi Zhang & Li, sp. nov. (♀). The DNA barcodes of the thirty-five new species are provided.

Eight new species of the spider genus Pimoa (Araneae, Pimoidae) from Tibet, China

Eight new species of the spider genus Pimoa Chamberlin & Ivie, 1943 are described from Tibet, China: P.cona Zhang & Li, sp. nov. (♂♀), P.duiba Zhang & Li, sp. nov. (♂♀), P.lemenba Zhang & Li, sp. nov. (♀), P.mainling Zhang & Li, sp. nov. (♂♀), P.nyingchi Zhang & Li, sp. nov. (♂♀), P.rongxar Zhang & Li, sp. nov. (♂♀), P.samyai Zhang & Li, sp. nov. (♂♀), and P.yadong Zhang & Li, sp. nov. (♂♀). The DNA barcodes of the eight new species are documented.

On three species of the spider genus Pimoa (Araneae, Pimoidae) from China

Two new species of the spider genus Pimoa Chamberlin & Ivie, 1943 are described from Hunan and Yunnan Provinces, China: P.binchuanensissp. nov. (♂♀) and P.xinjianensissp. nov. (♂♀). In addition, the male of P.lata Xu & Li, 2009 is described for the first time. The DNA barcodes of the two new species are documented.

Spiders in caves

World experts of different disciplines, from molecular biology to macro-ecology, recognize the value of cave ecosystems as ideal ecological and evolutionary laboratories. Among other subterranean taxa, spiders stand out as intriguing model organisms for their ecological role of top predators, their unique adaptations to the hypogean medium and their sensitivity to anthropogenic disturbance. As the description of the first eyeless spider (Stalita taenaria), an array of papers on subterranean spider biology, ecology and evolution has been published, but a comprehensive review on these topics is still lacking. We provide a general overview of the spider families recorded in hypogean habitats worldwide, we review the different adaptations of hypogean spiders to subterranean life, and we summarize the information gathered so far about their origin, population structure, ecology and conservation status. Finally, we point out the limits of the knowledge we currently have regarding hypogean spiders, aiming to stimulate future research.

Alpine endemic spiders shed light on the origin and evolution of subterranean species

We designed a comparative study to unravel the phylogeography of two Alpine endemic spiders characterized by a different degree of adaptation to subterranean life: Troglohyphantes vignai (Araneae, Linyphiidae) and Pimoa rupicola (Araneae, Pimoidae), the latter showing minor adaptation to hypogean life. We sampled populations of the model species in caves and other subterranean habitats across their known geographical range in the Western Alps. By combining phylogeographic inferences and Ecological Niche Modeling techniques, we inferred the biogeographic scenario that led to the present day population structure of the two species. According to our divergent time estimates and relative uncertainties, the isolation of T. vignai and P. rupicola from their northern sister groups was tracked back to Middle–Late Miocene. Furthermore, the fingerprint left by Pleistocene glaciations on the population structure revealed by the genetic data, led to the hypothesis that a progressive adaptation to subterranean habitats occurred in T. vignai, followed by strong population isolation. On the other hand, P. rupicola underwent a remarkable genetic bottleneck during the Pleistocene glaciations, that shaped its present population structure. It seems likely that such shallow population structure is both the result of the minor degree of specialization to hypogean life and the higher dispersal ability characterizing this species. The simultaneous study of overlapping spider species showing different levels of adaptation to hypogean life, disclosed a new way to clarify patterns of biological diversification and to understand the effects of past climatic shift on the subterranean biodiversity.

Unexpected diversity in the relictual European spiders of the genus Pimoa (Araneae : Pimoidae)

Pimoidae is a small family of araneoid spiders, hitherto represented in Europe by two species with disjunct distribution in the Alps and in the Cantabrian Mountains of northern Spain. Here we report the description of two additional European species of Pimoa, discovered within the range of the only former alpine species, P. rupicola: P. graphitica sp. nov. and P. delphinica sp. nov. The new species are distinguished from the latter by genitalic characters as well as by molecular characters. On the basis of the re-examination of old and recent abundant material collected in caves and other subterranean habitats, we revise the distribution patterns of the genus Pimoa in the Alps and outline the species distribution ranges. Molecular data suggest the existence of gene flow between populations of the two new species when in sympatry. The different species probably originated in the alpine region as a result of range contractions following dramatic climatic changes in the Alps since the mid Miocene. We interpreted the present-day overlapping distribution in light of a possible postglacial expansion. Finally, we provide insights on the natural history and life cycles of the new species and discuss their phylogenetic relationships within Pimoidae.

Systematics, phylogeny, and evolution of orb-weaving spiders

The orb-weaving spiders (Orbiculariae) comprise more than 25% of the approximately 44,000 known living spider species and produce a remarkable variety of webs. The wheel-shaped orb web is primitive to this clade, but most Orbiculariae make webs hardly recognizable as orbs. Orb-weavers date at least to the Jurassic. With no evidence for convergence of the orb web, the monophyly of the two typical orb web taxa, the cribellate Deinopoidea and ecribellate Araneoidea, remains problematic, supported only weakly by molecular studies. The sister group of the Orbiculariae also remains elusive. Despite more than 15 years of phylogenetic scrutiny, a fully resolved cladogram of the Orbiculariae families is not yet possible. More comprehensive taxon sampling, comparative morphology, and new molecular markers are required for a better understanding of orb-weaver evolution.

Toward understanding the distribution of Laurasian frogs: a test of Savage's biogeographical hypothesis using the genus Bombina

Several anuran groups of Laurasian origin are each co-distributed in four isolated regions of the Northern Hemisphere: central/southern Europe and adjacent areas, Korean Peninsula and adjacent areas, Indo-Malaya, and southern North America. Similar distribution patterns have been observed in diverse animal and plant groups. Savage [Savage, J.M., 1973. The geographic distribution of frogs: patterns and predictions. In: Vial, J.L. (Ed.), Evolutionary Biology of the Anurans. University of Missouri Press, Columbia, pp. 351-445] hypothesized that the Miocene global cooling and increasing aridities in interiors of Eurasia and North America caused a southward displacement and range contraction of Laurasian frogs (and other groups). We use the frog genus Bombina to test Savage's biogeographical hypothesis. A phylogeny of Bombina is reconstructed based on three mitochondrial and two nuclear gene fragments. The genus is divided into three major clades: an Indo-Malaya clade includes B. fortinuptialis, B. lichuanensis, B. maxima, and B. microdeladigitora; a European clade includes B. bombina, B. pachypus, and B. variegata; and a Korean clade contains B. orientalis. The European and Korean clades form sister-group relationship. Molecular dating of the phylogenetic tree using the penalized likelihood and Bayesian analyses suggests that the divergence between the Indo-Malaya clade and other Bombina species occurred 5.9-28.6 million years ago. The split time between the European clade and the Korean clade is estimated at 5.1-20.9 million years ago. The divergence times of these clades are not significantly later than the timing of Miocene cooling and drying, and therefore can not reject Savage's hypothesis. Some other aspects of biogeography of Bombina also are discussed. The Korean Peninsula and the Shandong Peninsula might have supplied distinct southern refugia for B. orientalis during the Pleistocene glacial maxima. In the Indo-Malaya clade, the uplift of the Tibetan Plateau might have promoted the split between B. maxima and the other species.