The Experts below are selected from a list of 1254 Experts worldwide ranked by ideXlab platform
Gustavo Hormiga - One of the best experts on this subject based on the ideXlab platform.
-
www.mapress.com/zootaxa/ Article
2015Co-Authors: Gustavo Hormiga, Nikolaj ScharffAbstract:Australia with a preference for thorny plants (Araneae, Linyphiidae
-
Pedipalp sclerite homologies and phylogenetic placement of the spider genus Stemonyphantes (Linyphiidae, Araneae) and its implications for linyphiid phylogeny
Invertebrate Systematics, 2013Co-Authors: Efrat Gavish-regev, Gustavo Hormiga, Nikolaj ScharffAbstract:Male secondary genitalia (pedipalps) are useful characters for species discrimination in most spider families. Although efforts have been made to establish pedipalp sclerite homologies, there are still many inconsistencies in their use. The majority of the morphological characters used to reconstruct the linyphiid phylogeny address male genitalic variation; these inconsistencies may affect the phylogeny and our understanding of linyphiid evolution. Stemonyphantes Menge, 1866, has been hypothesised to be sister to all remaining Linyphiidae. However, despite the basal position of Stemonyphantes, its pedipalp sclerite homologies are not well understood and, along with its monophyly, have never been thoroughly tested in a phylogenetic context. We tested the homology of tegular and radical structures of five Stemonyphantes species to the known linyphioid and araneoid sclerites. All minimum-length trees found under all analytical methods used support Stemonyphantes monophyly and its placement as the sister group to all other Linyphiidae. Our study suggests that Stemonyphantes, unlike any other linyphiids, does have homologues of the araneoid median apophysis and conductor. As Stemonyphantes is the sister group of all other linyphiids, resolving its pedipalp sclerite homologies is critical for understanding sclerite homologies and the phylogeny of the entire family.
-
phylogeny of the orb web building spiders araneae orbiculariae deinopoidea araneoidea
Zoological Journal of the Linnean Society, 1998Co-Authors: Charles E Griswold, Jonathan A Coddington, Gustavo Hormiga, Nikolaj ScharffAbstract:Abstract This phylogenetic analysis of 31 exemplar taxa treats the 12 families of Araneoidea (Anapidae, Araneidae, Cyatholipidae, Linyphiidae, Mysmenidae, Nesticidae, Pimoidae, Symphytognathidae, Synotaxidae, Tetragnathidae, Theridiidae, and Theridiosomatidae). The data set comprises 93 characters: 23 from male genitalia, 3 from female genitalia, 18 from cephalothorax morphology, 6 from abdomen morphology, 14 from limb morphology, 15 from the spinnerets, and 14 from web architecture and other behaviour. Criteria for tree choice were minimum length parsimony and parsimony under implied weights. The outgroup for Araneoidea is Deinopoidea (Deinopidae and Uloboridae). The preferred shortest tree specifies the relationships ((Uloboridae, Deinopidae) (Araneidae (Tetragnathidae ((Theridiosomatidae (Mysmenidae (Symphytognathidae, Anapidae))) ((Linyphiidae, Pimoidae) ((Theridiidae, Nesticidae) (Cyatholipidae, Synotaxidae))))))). The monophyly of Tetragnathidae (including metines and nephilines), the symphytognathoids, theridiid-nesticid lineage, and Synotaxidae are confirmed. Cyatholipidae are sister to Synotaxidae, not closely related to either the Araneidae or Linyphiidae, as previously suggested. Four new clades are proposed: the cyatholipoids (Cyatholipidae plus Synotaxidae), the «spineless femur clade» (theridioid lineage plus cyatholipoids), the «araneoid sheet web builders» (linyphioids plus the spineless femur clade), and the «reduced piriform clade» (symphytognathoids plus araneoid sheet web builders). The results imply a coherent scenario for web evolution in which the monophyletic orb gives rise to the monophyletic araneoid sheet, which in turn gives rise to the gumfoot web of the theridiid-nesticid lineage. While the spinning complement of single pairs of glands does not change much over the evolution of the group, multiple sets of glands are dramatically reduced in number, implying that derived araneoids are incapable of spinning many silk fibers at the same time.
-
Phylogeny of the orb-web building spiders (Araneae, Orbiculariae
1998Co-Authors: Charles E Griswold, Jonathan A Coddington, Gustavo Hormiga, Nikolaj ScharffAbstract:data set comprises 93 characters: 23 from male genitalia, 3 from female genitalia, 18 from cephalothorax morphology, 6 from abdomen morphology, 14 from limb morphology, 15 from the spinnerets, and 14 from web architecture and other behaviour. Criteria for tree choice were minimum length parsimony and parsimony under implied weights. The outgroup for Araneoidea is Deinopoidea (Deinopidae and Uloboridae). The preferred shortest tree specifies the relationships ((Uloboridae, Deinopidae) (Araneidae (Tetragnathidae ((Theri-diosomatidae (Mysmenidae (Symphytognathidae, Anapidae))) ((Linyphiidae, Pimoidae) ((Theridiidae, Nesticidae) (Cyatholipidae, Synotaxidae))))))). The monophyly of Tetragnathidae (including metines and nephilines), the symphytognathoids, theridiid-nesticid lineage, and Synotaxidae are confirmed. Cyatholipidae are sister to Synotaxidae, not closely related to either the Araneidae or Linyphiidae, as previously suggested. Four new clades are proposed: the cyatholipoids (Cyatholipidae plus Synotaxidae), the ‘spineless femur clade ’ (theridioid lineage plus cyatholipoids), the ‘araneoid sheet web builders ’ (linyphioids plus the spineless femur clade), and the ‘reduced piriform clade ’ (symphytognathoids plus araneoid sheet web builders). The results imply a coherent scenario for web evolution in which the monophyleti
-
cladistics and the comparative morphology of linyphiid spiders and their relatives araneae araneoidea Linyphiidae
Zoological Journal of the Linnean Society, 1994Co-Authors: Gustavo HormigaAbstract:This paper provides the first quantitative cladistic analysis of linyphiid morphology. Classical and novel homology hypotheses for a variety of character systems (male and female genitalia, somatic morphology, spinneret silk spigot morphology, etc.) are critically examined and studied within a phylogenetic context. Critical characters have been illustrated. A sample of linyphiid taxa (nine genera in four subfamilies), five species of Pimoa (Pimoidae), and two other araneoid families (Tetragnathidae and Araneidae, represented by Tetragnatha and Zygiella, respectively) were used to study the implications of the phylogeny of Pimoidae for the systematics of linyphiids. The phylogenetic relationships of these 16 exemplar taxa, as coded for the 47 characters studied, were analysed using numerical cladistic methods. In the preferred cladogram Pimoidae and Linyphiidae are sister groups, Stemonyphantinae are sister group to the remaining linyphiids, and Mynogleninae are sister group to the clade composed of Erigoninae plus Linyphiinae. These results agree with the relationships recently proposed by Wunderlich, except by finding erigonines as the sister group to linyphiines rather than to mynoglenines.
Nikolaj Scharff - One of the best experts on this subject based on the ideXlab platform.
-
www.mapress.com/zootaxa/ Article
2015Co-Authors: Gustavo Hormiga, Nikolaj ScharffAbstract:Australia with a preference for thorny plants (Araneae, Linyphiidae
-
Pedipalp sclerite homologies and phylogenetic placement of the spider genus Stemonyphantes (Linyphiidae, Araneae) and its implications for linyphiid phylogeny
Invertebrate Systematics, 2013Co-Authors: Efrat Gavish-regev, Gustavo Hormiga, Nikolaj ScharffAbstract:Male secondary genitalia (pedipalps) are useful characters for species discrimination in most spider families. Although efforts have been made to establish pedipalp sclerite homologies, there are still many inconsistencies in their use. The majority of the morphological characters used to reconstruct the linyphiid phylogeny address male genitalic variation; these inconsistencies may affect the phylogeny and our understanding of linyphiid evolution. Stemonyphantes Menge, 1866, has been hypothesised to be sister to all remaining Linyphiidae. However, despite the basal position of Stemonyphantes, its pedipalp sclerite homologies are not well understood and, along with its monophyly, have never been thoroughly tested in a phylogenetic context. We tested the homology of tegular and radical structures of five Stemonyphantes species to the known linyphioid and araneoid sclerites. All minimum-length trees found under all analytical methods used support Stemonyphantes monophyly and its placement as the sister group to all other Linyphiidae. Our study suggests that Stemonyphantes, unlike any other linyphiids, does have homologues of the araneoid median apophysis and conductor. As Stemonyphantes is the sister group of all other linyphiids, resolving its pedipalp sclerite homologies is critical for understanding sclerite homologies and the phylogeny of the entire family.
-
phylogeny of the orb web building spiders araneae orbiculariae deinopoidea araneoidea
Zoological Journal of the Linnean Society, 1998Co-Authors: Charles E Griswold, Jonathan A Coddington, Gustavo Hormiga, Nikolaj ScharffAbstract:Abstract This phylogenetic analysis of 31 exemplar taxa treats the 12 families of Araneoidea (Anapidae, Araneidae, Cyatholipidae, Linyphiidae, Mysmenidae, Nesticidae, Pimoidae, Symphytognathidae, Synotaxidae, Tetragnathidae, Theridiidae, and Theridiosomatidae). The data set comprises 93 characters: 23 from male genitalia, 3 from female genitalia, 18 from cephalothorax morphology, 6 from abdomen morphology, 14 from limb morphology, 15 from the spinnerets, and 14 from web architecture and other behaviour. Criteria for tree choice were minimum length parsimony and parsimony under implied weights. The outgroup for Araneoidea is Deinopoidea (Deinopidae and Uloboridae). The preferred shortest tree specifies the relationships ((Uloboridae, Deinopidae) (Araneidae (Tetragnathidae ((Theridiosomatidae (Mysmenidae (Symphytognathidae, Anapidae))) ((Linyphiidae, Pimoidae) ((Theridiidae, Nesticidae) (Cyatholipidae, Synotaxidae))))))). The monophyly of Tetragnathidae (including metines and nephilines), the symphytognathoids, theridiid-nesticid lineage, and Synotaxidae are confirmed. Cyatholipidae are sister to Synotaxidae, not closely related to either the Araneidae or Linyphiidae, as previously suggested. Four new clades are proposed: the cyatholipoids (Cyatholipidae plus Synotaxidae), the «spineless femur clade» (theridioid lineage plus cyatholipoids), the «araneoid sheet web builders» (linyphioids plus the spineless femur clade), and the «reduced piriform clade» (symphytognathoids plus araneoid sheet web builders). The results imply a coherent scenario for web evolution in which the monophyletic orb gives rise to the monophyletic araneoid sheet, which in turn gives rise to the gumfoot web of the theridiid-nesticid lineage. While the spinning complement of single pairs of glands does not change much over the evolution of the group, multiple sets of glands are dramatically reduced in number, implying that derived araneoids are incapable of spinning many silk fibers at the same time.
-
Phylogeny of the orb-web building spiders (Araneae, Orbiculariae
1998Co-Authors: Charles E Griswold, Jonathan A Coddington, Gustavo Hormiga, Nikolaj ScharffAbstract:data set comprises 93 characters: 23 from male genitalia, 3 from female genitalia, 18 from cephalothorax morphology, 6 from abdomen morphology, 14 from limb morphology, 15 from the spinnerets, and 14 from web architecture and other behaviour. Criteria for tree choice were minimum length parsimony and parsimony under implied weights. The outgroup for Araneoidea is Deinopoidea (Deinopidae and Uloboridae). The preferred shortest tree specifies the relationships ((Uloboridae, Deinopidae) (Araneidae (Tetragnathidae ((Theri-diosomatidae (Mysmenidae (Symphytognathidae, Anapidae))) ((Linyphiidae, Pimoidae) ((Theridiidae, Nesticidae) (Cyatholipidae, Synotaxidae))))))). The monophyly of Tetragnathidae (including metines and nephilines), the symphytognathoids, theridiid-nesticid lineage, and Synotaxidae are confirmed. Cyatholipidae are sister to Synotaxidae, not closely related to either the Araneidae or Linyphiidae, as previously suggested. Four new clades are proposed: the cyatholipoids (Cyatholipidae plus Synotaxidae), the ‘spineless femur clade ’ (theridioid lineage plus cyatholipoids), the ‘araneoid sheet web builders ’ (linyphioids plus the spineless femur clade), and the ‘reduced piriform clade ’ (symphytognathoids plus araneoid sheet web builders). The results imply a coherent scenario for web evolution in which the monophyleti
Tu Lihong - One of the best experts on this subject based on the ideXlab platform.
-
Figure 1 from: Bao M, Bai Z, Tu L (2017) On a desmitracheate "micronetine" Nippononeta alpina (Li & Zhu, 1993), comb. n. (Araneae, Linyphiidae). ZooKeys 645: 133-146. https://doi.org/10.3897/zookeys.645.10685
2017Co-Authors: Bao Mengdie, Bai Zishang, Tu LihongAbstract:Figure 1 - Linyphiid phylogeny resulting from the Maximum Likelihood analysis based on DNA sequence data. Numbers at nodes indicate bootstrap support above 50%. Branches in color represent seven robustly supported main clades within Linyphiidae. Branches in bold indicate the desmitracheate type. Taxa in blue are currently placed in Micronetinae
-
On the desmitracheate "micronetine" genus Nippononeta Eskov, 1992 (Araneae, Linyphiidae)
2015Co-Authors: Yan Ming, Liang Xiaokai, Tu LihongAbstract:The desmitracheate system in a "micronetine" genus Nippononeta Eskov, 1992 is recognized for the first time in the present study. This makes the subfamilial placement of this genus problematic. A morphological study was conducted for N. kurilensis Eskov, 1992 (the type species of Nippononeta) and N. coreana (Paik, 1991). Characters of genitalia and tracheal system, as well as some somatic characters were studied in detail by using scanning electronic microscopy (SEM), and compared with those of Agyneta. Updated descriptions of the genus Nippononeta and its two species are presented. Putative synapomorphies for Nippononeta and Agyneta are provided, as well as some putative synapomorphies shared by the two genera. The results imply that both scaped epigynum and desmitracheate tracheal system are probably homoplastic. The placement of Nippononeta and Agyneta within Linyphiidae need to be resolved in future studies
Rubio, Gonzalo Daniel - One of the best experts on this subject based on the ideXlab platform.
-
Diversidad de arañas (Araneae, Araneomorphae) en la selva de montaña: un caso de estudio en las Yungas Argentinas
Museo Nacional de Ciencias Naturales, 2017Co-Authors: Rubio, Gonzalo DanielAbstract:Se estudia la diversidad de arañas de vegetación de las yungas del noroeste argentino, integrando dos escalas: local (diversidad α, estructura de comunidades) y su proyección a diversidad regional (diversidad β). Se muestrearon 26 sitios en la provincia de Salta, representando diferentes ambientes/pisos altitudinales de yungas sensu stricto (SP= selva pedemontana, SM= selva montana, BM= bosque montano), yungas sensu lato (Cc-s= conectividad entre centro y sur de yungas, YT= yungas en transición) y sitios de Chaco Serrano (ChS) como contraste. Se realizaron muestreos estacionales durante un año, tomando 10 muestras con G-Vac (aspirador entomológico) sobre vegetación. Se obtuvo un total de 6412 ejemplares, representando 188 especies y 34 familias (sólo yungas). Theridiidae, Anyphaenidae y Linyphiidae fueron dominantes. La mayor riqueza correspondió a Araneidae, Salticidae y Theridiidae. Especies dominantes fueron Chibchea salta (Pholcidae), Dubiaranea msp111 (Linyphiidae) y Mysmena msp110 (Mysmenidae). Diferencias relevantes en composición y abundancia separan dos grupos de ambientes: (Cc-s+SP+YT+ChS) vs. (SM+BM). Dictynidae, Oxyopidae y Philodromidae se asocian a pisos de menor altitud (Cc-s, YT, ChS). Los ambientes SP y YT contienen la mayor riqueza específica y diversidad, mientras que SM y BM presentaron la mayor similitud. En Cc-s y ChS se observaron las mayores diferencias con los demás ambientes, excepto SP. La complementariedad y coeficientes e índices de similitud revelaron alta diversidad β en la región. En consecuencia, se sugiere que además de reforzar la protección en los pisos transicionales de yungas (hábitats más deteriorados y diversos para las arañas), la gestión de conservación debería estar orientada en toda el área a promover la heterogeneidad espacial natural de las Yungas, haciendo especial hincapié en el mosaico de hábitats que constituyen cada estrato diferente.The spider diversity from yungas vegetation in northwestern Argentina is studied, integrating two levels: local (α diversity, community structures) and a projection at regional level of diversity (β diversity). Twenty six sites in Salta Province were sampled, representing different ambient/altitudinal strata of yungas sensu stricto (SP= pedemontane rainforest, SM= montane rainforest and BM= montane forest), yungas sensu lato (Cc-s= yungas central and southern sectors connectivity areas, YT= transitional yungas), and Chaco Serrano sites (ChS) as contrast. The sampling was carried out seasonally for one year taking 10 samples of vegetation with G-Vac method. A total of 6412 spiders, 188 species and 34 families were obtained (only yungas). Theridiidae, Anyphaenidae and Linyphiidae were dominant. The highest richness was observed in Araneidae, Salticidae and Theridiidae. Chibchea salta (Pholcidae), Dubiaranea msp111 (Linyphiidae) and Mysmena msp110 (Mysmenidae) were dominant species. Relevant differences in species composition and abundance highlighted two groups of environment (Cc-s+SP+YT+ChS) vs. (SM+BM). Dictynidae, Oxyopidae and Philodromidae are associated with lower altitudinal floors (Cc-s, YT, ChS). The greatest species richness and diversity were recorded in SP and YT. The highest similarity was recorded in SM and BM; the major differences were observed in Cc-s and ChS compared with the other ambient, except with SP. Complementarity and similarity indices and coefficients revealed high β diversity in the region. Thus, it is suggested that besides reinforcing protection in transitional levels Yungas (the most disturbed and diverse habitats for spiders), conservation management in the area should be directed towards promoting natural spatial heterogeneity of Yungas, giving special emphasis to habitat mosaics that constitute each different stratum.Fil: Rubio, Gonzalo Daniel. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Nordeste. Instituto de Biologia Subtropical. Instituto de Biologia Subtropical - Nodo Puerto Iguazu; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Forestales; Argentin
Rubio, Gonzalo D. - One of the best experts on this subject based on the ideXlab platform.
-
Diversidad de arañas (Araneae, Araneomorphae) en la selva de montaña: un caso de estudio en las Yungas Argentinas
Consejo Superior de Investigaciones Científicas, 2015Co-Authors: Rubio, Gonzalo D.Abstract:The spider diversity from yungas vegetation in northwestern Argentina is studied, integrating two levels: local (α diversity, community structures) and a projection at regional level of diversity (β diversity). Twenty six sites in Salta Province were sampled, representing different ambient/altitudinal strata of yungas sensu stricto (SP= pedemontane rainforest, SM= montane rainforest and BM= montane forest), yungas sensu lato (Cc-s= yungas central and southern sectors connectivity areas, YT= transitional yungas), and Chaco Serrano sites (ChS) as contrast. The sampling was carried out seasonally for one year taking 10 samples of vegetation with G-Vac method. A total of 6412 spiders, 188 species and 34 families were obtained (only yungas). Theridiidae, Anyphaenidae and Linyphiidae were dominant. The highest richness was observed in Araneidae, Salticidae and Theridiidae. >em>Chibchea salta (Pholcidae), Dubiaranea msp111 (Linyphiidae) and Mysmena msp110 (Mysmenidae) were dominant species. Relevant differences in species composition and abundance highlighted two groups of environment (Cc-s+SP+YT+ChS) vs. (SM+BM). Dictynidae, Oxyopidae and Philodromidae are associated with lower altitudinal floors (Cc-s, YT, ChS). The greatest species richness and diversity were recorded in SP and YT. The highest similarity was recorded in SM and BM; the major differences were observed in Cc-s and ChS compared with the other ambient, except with SP. Complementarity and similarity indices and coefficients revealed high β diversity in the region. Thus, it is suggested that besides reinforcing protection in transitional levels Yungas (the most disturbed and diverse habitats for spiders), conservation management in the area should be directed towards promoting natural spatial heterogeneity of Yungas, giving special emphasis to habitat mosaics that constitute each different stratum.Se estudia la diversidad de arañas de vegetación de las yungas del noroeste argentino, integrando dos escalas: local (diversidad α, estructura de comunidades) y su proyección a diversidad regional (diversidad β). Se muestrearon 26 sitios en la provincia de Salta, representando diferentes ambientes/pisos altitudinales de yungas sensu stricto (SP= selva pedemontana, SM= selva montana, BM= bosque montano), yungas sensu lato (Cc-s= conectividad entre centro y sur de yungas, YT= yungas en transición) y sitios de Chaco Serrano (ChS) como contraste. Se realizaron muestreos estacionales durante un año, tomando 10 muestras con G-Vac (aspirador entomológico) sobre vegetación. Se obtuvo un total de 6412 ejemplares, representando 188 especies y 34 familias (sólo yungas). Theridiidae, Anyphaenidae y Linyphiidae fueron dominantes. La mayor riqueza correspondió a Araneidae, Salticidae y Theridiidae. Especies dominantes fueron Chibchea salta (Pholcidae), Dubiaranea msp111 (Linyphiidae) y Mysmena msp110 (Mysmenidae). Diferencias relevantes en composición y abundancia separan dos grupos de ambientes: (Cc-s+SP+YT+ChS) vs. (SM+BM). Dictynidae, Oxyopidae y Philodromidae se asocian a pisos de menor altitud (Cc-s, YT, ChS). Los ambientes SP y YT contienen la mayor riqueza específica y diversidad, mientras que SM y BM presentaron la mayor similitud. En Cc-s y ChS se observaron las mayores diferencias con los demás ambientes, excepto SP. La complementariedad y coeficientes e índices de similitud revelaron alta diversidad β en la región. En consecuencia, se sugiere que además de reforzar la protección en los pisos transicionales de yungas (hábitats más deteriorados y diversos para las arañas), la gestión de conservación debería estar orientada en toda el área a promover la heterogeneidad espacial natural de las Yungas, haciendo especial hincapié en el mosaico de hábitats que constituyen cada estrato diferente
