14 research outputs found

    Revision of the Neotropical spider genus Gephyroctenus (Araneae: Ctenidae: Calocteninae)

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    Gephyroctenus Mello-LeitĂŁo, 1936 (type species G. philodromoides Mello-LeitĂŁo, 1936) is revised. Three species formerly described in this genus are synonymized with species from other genera: G. kolosvaryi Caporiacco, 1947, with Acanthoctenus spinipes Keyserling, 1877, G. parvus Caporiacco, 1947, with Phymatoctenus comosus Simon, 1897, and G. vachoni Caporiacco, 1955, with Caloctenus gracilitarsis Simon, 1897. Eight new species are described: G. portovelho sp. nov., from the States of RondĂŽnia and Amazonas, Brazil; G. divisor sp. nov. and G. acre sp. nov., from the State of Acre, Brazil; G. atininga sp. nov., G. esteio sp. nov. and G. mapia sp. nov., from the State of Amazonas, Brazil; G. juruti sp. nov., from the Department of Loreto, Peru and the State of ParĂĄ, Brazil; G. panguana sp. nov., from the Department of Huanuco, Peru. The genus can be distinguished by the presence of a cymbial retrolateral groove, retrolateral origin of embolus, embolus long and thin, median apophysis with a subdistal hook, and hyaline projection close to the embolus base in the male palp and by the fused median and lateral fields in a single epigynal plate, copulatory opening located dorsally in an atrium, and elongated copulatory ducts surrounding the spermathecae in the female epigynum. Field observations on the hunting behavior on ants in trumpet trees (Cecropia) are provided for two species, G. philodromoides and G. mapia sp. nov.<br>Gephyroctenus Mello-LeitĂŁo, 1936 (espĂ©cie-tipo G. philodromoides Mello-LeitĂŁo, 1936), Ă© revisado. TrĂȘs espĂ©cies descritas neste gĂȘnero sĂŁo sinonimizadas com espĂ©cies de outros gĂȘneros: G. kolosvaryi Caporiacco, 1947, com Acanthoctenus spinipes Keyserling, 1877, G. parvus Caporiacco, 1947, com Phymatoctenus comosus Simon, 1897, e G. vachoni Caporiacco, 1955, com Caloctenus gracilitarsis Simon, 1897. Oito novas espĂ©cies sĂŁo descritas: G. portovelho sp. nov., dos Estados de RondĂŽnia e Amazonas, Brasil; G. divisor sp. nov. e G. acre sp. nov., do Estado do Acre, Brasil; G. atininga sp. nov., G. esteio sp. nov. e G. mapia sp. nov., do Estado do Amazonas, Brasil; G. juruti sp. nov., do Department de Loreto, Peru e Estado do ParĂĄ, Brazil; e G. panguana sp. nov., do Department de Huanuco, Peru. Os machos do gĂȘnero podem ser distinguidos pela presença de uma fenda retrolateral no cĂ­mbio, origem retrolateral do ĂȘmbolo, ĂȘmbolo longo e fino, apĂłfise mĂ©dia com um gancho subdistal e projeção hialina na base do ĂȘmbolo no palpo, e as fĂȘmeas podem ser distinguidas pelos campo mediano e campos laterais fundidos em uma Ășnica placa, aberturas copulatĂłrias localizadas em um ĂĄtrio e dutos copulatĂłrios alongados no epĂ­gino. ObservaçÔes de campo sobre o comportamento de caça de formigas em embaĂșbas (Cecropia) sĂŁo fornecidas para duas espĂ©cies deste gĂȘnero, G. philodromoides e G. mapia sp. nov

    Phylogeny of the orb-weaving spider family Araneidae (Araneae: Araneoidea)

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    We present a new phylogeny of the spider family Araneidae based on five genes (28S, 18S, COI, H3 and 16S) for 158 taxa, identified and mainly sequenced by us. This includes 25 outgroups and 133 araneid ingroups representing the subfamilies Zygiellinae Simon, 1929, Nephilinae Simon, 1894, and the typical araneids, here informally named the “ARA Clade”. The araneid genera analysed here include roughly 90% of all currently named araneid species. The ARA Clade is the primary focus of this analysis. In taxonomic terms, outgroups comprise 22 genera and 11 families, and the ingroup comprises three Zygiellinae and four Nephilinae genera, and 85 ARA Clade genera (ten new). Within the ARA Clade, we recognize ten informal groups that contain at least three genera each and are supported under Bayesian posterior probabilities (≄ 0.95): “Caerostrines” (Caerostris, Gnolus and Testudinaria), “Micrathenines” (Acacesia, Micrathena, Ocrepeira, Scoloderus and Verrucosa), “Eriophorines” (Acanthepeira, Alpaida, Eriophora, Parawixia and Wagneriana), “Backobourkiines” (Acroaspis, Backobourkia, Carepalxis, Novakiella, Parawixia, Plebs, Singa and three new genera), “Argiopines” (Arachnura, Acusilas, Argiope, Cyrtophora, Gea, Lariniaria and Mecynogea), “Cyrtarachnines” (Aranoethra, Cyrtarachne, Paraplectana, Pasilobus and Poecilopachys), “Mastophorines” (Celaenia, Exechocentrus and Mastophora,), “Nuctenines” (Larinia, Larinioides and Nuctenea), “Zealaraneines” (Colaranea, Cryptaranea, Paralarinia, Zealaranea and two new genera) and “Gasteracanthines” (Augusta, Acrosomoides, Austracantha, Gasteracantha, Isoxya, Macracantha, Madacantha, Parmatergus and Thelacantha). Few of these groups are currently corroborated by morphology, behaviour, natural history or biogeography. We also include the large genus Araneus, along with Aculepeira, Agalenatea, Anepsion, Araniella, Cercidia, Chorizopes, Cyclosa, Dolophones, Eriovixia, Eustala, Gibbaranea, Hingstepeira, Hypognatha, Kaira, Larinia, Mangora, Metazygia, Metepeira, Neoscona, Paraplectanoides, Perilla, Poltys, Pycnacantha, Spilasma and Telaprocera, but the placement of these genera was generally ambiguous, except for Paraplectanoides, which is strongly supported as sister to traditional Nephilinae. Araneus, Argiope, Eriophora and Larinia are polyphyletic, Araneus implying nine new taxa of genus rank, and Eriophora and Larinia two each. In Araneus and Eriophora, polyphyly was usually due to north temperate generic concepts being used as dumping grounds for species from southern hemisphere regions, e.g. South‐East Asia, Australia or New Zealand. Although Araneidae is one of the better studied spider families, too little natural history and/or morphological data are available across these terminals to draw any strong evolutionary conclusions. However, the classical orb web is reconstructed as plesiomorphic for Araneidae, with a single loss in “cyrtarachnines”–“mastophorines”. Web decorations (collectively known as stabilimenta) evolved perhaps five times. Sexual dimorphism generally results from female body size increase with few exceptions; dimorphic taxa are not monophyletic and revert to monomorphism in a few cases.acceptedVersio
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