Browsing by Author "Hormiga, Gustavo."
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ItemFirst records of extant Hispaniolan spiders of the families Mysmenidae, Symphytognathidae, and Ochyroceratidae (Araneae), including a new species of Ochyrocera ; American Museum novitates, no. 3577(New York, NY : American Museum of Natural History, 2007) Hormiga, Gustavo.; Alvarez-Padilla, Fernando.; Benjamin, Suresh P.A new species of ochyroceratid spider, Ochyrocera cachote, n.sp., is described and its unique web architecture is documented. This is the first record of Ochyroceratidae for the extant fauna of Hispaniola. Additional new family records include Symphytognathidae (Patu sp. and Symphytognatha sp.) and Mysmenidae (Microdipoena sp.), with the latter family having been previously recorded from the fossil amber fauna. This makes a new total of 46 spider families recorded from the extant Hispaniolan fauna, but on the whole the island's araneofauna remains poorly known and warrants further investigation. ItemOn the phylogenetic placement of the spider genus Atimiosa Simon, 1895, and the circumscription of Dolichognatha O.P.-Cambridge, 1869 (Tetragnathidae, Araneae). (American Museum novitates, no. 3683)(New York, NY : American Museum of Natural History., 2010) Dimitrov, Dimitar.; Álvarez-Padilla, Fernando.; Hormiga, Gustavo.The genus Atimiosa Simon, 1895, is a junior synonym of Dolichognatha O. P.-Cambridge, 1869. This synonymy is strongly supported by cladistic analyses of morphological characters and examination of types of all known Atimiosa species. Two new combinations resulted from this nomenclatural change, Dolichognatha comorensis (Schmidt and Krause, 1993), new combination, and Dolichognatha quinquemucronata (Simon, 1895), new combination. New illustrations and photographs of these two species and of the poorly known Dolichognatha longiceps (Thorell, 1895) are provided. We also describe for the first time the web architecture of D. longiceps. ItemOn the synaphrid spider Cepheia longiseta (Simon 1881) (Araneae, Synaphridae) ; American Museum novitates, no. 3575(New York, NY : American Museum of Natural History, 2007) Lopardo, Lara.; Hormiga, Gustavo.We redescribe the monotypic spider genus Cepheia and provide detailed morphological information on its type species, Cepheia longiseta. We provide the first exhaustive diagnosis for the genus, including for the first time detailed information about its external morphology as well as its tracheal system. Some morphological features previously proposed as synapomorphies for the Synaphridae are also present in Cepheia, which corroborates some of the diagnostic characters of the family. We also propose new synapomorphies for Synaphridae. ItemRevision and cladistic analysis of the orbweaving spider genus Cyrtognatha Keyserling, 1881 (Araneae, Tetragnathidae) (Bulletin of the American Museum of Natural History, no. 317)(2009) Dimitrov, Dimitar.; Hormiga, Gustavo.The Neotropical spiders of the orbweaving genus Cyrtognatha Keyserling, 1881 (Tetragnathidae) are monographed. Cyrtognatha now includes a total of 21 species distributed over a large part of South America, Central America, and the southern parts of North America. Several species are known from the Caribbean islands of Cuba (one species), Hispaniola (two species), Jamaica (one species), and Saint Vincent (one species). Despite the wide geographic distribution of the genus, most Cyrtognatha species are known from single localities and often from very few museum specimens. The web architecture of several Cyrtognatha species is described and illustrated for the first time. Adults and juveniles of Cyrtognatha can be easily distinguished from all other tetragnathids by the presence of a straight line of long and robust macrosetae with enlarged bases on the retrolateral surface of the PLS. In Cyrtognatha the spermathecae are reduced and the sperm storage function is undertaken by an unpaired membranous structure, the posterior sac, which is diagnostic for the genus. A cladistic analysis including all known species of Cyrtognatha plus 51 outgroup taxa scored for a total of 194 morphological and behavioral characters was carried out. Thirteen unambiguous synapomorphies support the monophyly of Cyrtognatha, six of which are free of homoplasy. The internal phylogenetic relationships within the genus are also hypothesized and discussed. The genus Agriognatha O.P.-Cambridge, 1896 is a junior synonym of Cyrtognatha. The following eight new combinations are proposed: C. pachygnathoides (O.P.-Cambridge, 1894), C. bella (O.P.-Cambridge, 1896), C. lepida (O.P.-Cambridge, 1889), C. simoni (Bryant, 1940), C. rucilla (Bryant, 1945), C. espanola (Bryant, 1945), C. bryantae (Chickering, 1956), and C. insolita (Chickering, 1956). The following 11 new species are described: C. catia, n. sp., C. atopica, n. sp., C. eberhardi, n. sp., C. quichua, n. sp., C. waorani, n. sp., C. morona, n. sp., C. leviorum, n. sp., C. petila, n. sp., C. paradoxa, n. sp., C. orphana, n. sp., and C. pathetica, n. sp. The species C. aproducta Franganillo, 1926 is considered a nomen dubium. The following three new combinations are the result of generic misplacements: Tetragnatha lactensis (Mello-Leitão, 1947), T. exilima (Mello-Leitão, 1943), and Glenognatha globosa (Petrunkevitch, 1925). ItemSpinneret spigot morphology in synaphrid spiders (Araneae, Synaphridae), with comments on the systematics of the family and description of a new species of Synaphris Simon 1894 from Spain ; American Museum novitates, no. 3556(New York, NY : American Museum of Natural History, 2007) Lopardo, Lara.; Hormiga, Gustavo.; Melic, Antonio.We describe for the first time the spigot morphology of two synaphrid species (one of each of two synaphrid genera, Synaphris and Cepheia) as well as the morphology of the respiratory system of Synaphris. We also provide a taxonomic description of a new species of Synaphris from Spain, including detailed information about its morphology. This new species is known only from males, and it might belong to the so-called letourneuxi species group. Some morphological features proposed as synapomorphies for the genus Synaphris and/or the Synaphridae are questioned and discussed. Putative synapomorphies proposed here include a distinct constriction on the tarsus-metatarsus joints; a cheliceral keel ending in a strong promarginal cheliceral tooth; scarce number of maxillary setae; distal maxillary setae clavate; and a characteristic palpal morphology, comprising a distinctive tibial morphology, a modified cymbium with two separate areas, a palpal dorsal translucent expansion of the embolar base, a retrolateral paracymbium, a reduced furrow separating the major ampullate field from the piriform field, and the retention of at least one triad spigot in males. Refuted synapomorphies are the metatarsal subdistal anastomosed lyriform organ, the notched tibial trichobothrial base, and the tarsal pseudosegmentation. We also discuss the phylogenetic placement of the family, suggesting a close relationship to the araneoid Cyatholipidae. ItemSystematics of the goblin spider genus Opopaea (Araneae, Oonopidae) in Madagascar. (Bulletin of the American Museum of Natural History, no. 380)(American Museum of Natural History., 2013-08-16) Andriamalala, Daniela.; Hormiga, Gustavo.; Goblin Spider Planetary Biodiversity Inventory.The Opopaea fauna of Madagascar is documented for the first time. There are 27 species of Opopaea on the island of which 26 are newly described here and 25 are apparently endemic to Madagascar: Opopaea andranomay, n. sp., O. ankarafantsika, n. sp., O. ankarana, n. sp., O. antsalova, n. sp., O. andringitra, n. sp., O. antsiranana, n. sp., O. bemarivo, n. sp., O. bemaraha, n. sp., O. berenty, n. sp., O. betioky, n. sp., O. itampolo, n. sp., O. kirindy, n. sp., O. manderano, n. sp., O. mahafaly, n. sp., O. manongarivo, n. sp., O. namoroka, n. sp., O. sandranantitra, n. sp., O. torotorofotsy, n. sp., O. tsimaloto, n. sp., O. tsimbazaza, n. sp., O. tsimembo, n. sp., O. tsinjoriaky, n. sp., O. tsingy, n. sp., O. vohibazaha, n. sp., O. foulpointe, n. sp. and O. maroantsetra, n. sp. (shared with Kenya and the Comoros Islands), and O. concolor (Blackwall, 1859), a cosmopolitan species. All species are described and illustrated. An identification key to the species and maps of their distribution in Madagascar are also provided. ItemTarsal organ morphology and the phylogeny of goblin spiders (Araneae, Oonopidae), with notes on basal genera. (American Museum novitates, no. 3736)(American Museum of Natural History., 2012-02-29) Platnick, Norman I.; Abrahim, Naiara.; Alvarez-Padilla, Fernando.; Andriamalala, Daniela.; Baehr, Barbara, 1953-; Baert, L.; Bonaldo, Alexandre B.; Brescovit, Antonio D.; Chousou-Polydouri, Natalia.; Dupérré, N. (Nadine); Eichenberger, Beata.; Fannes, Wouter.; Gaublomme, Eva.; Gillespie, Rosemary G., 1957-; Grismado, Cristian J.; Griswold, Charles E.; Harvey, Mark S.; Henrard, Arnaud.; Hormiga, Gustavo.; Izquierdo, Matías A.; Jocqué, R.; Kranz-Baltensperger, Yvonne.; Kropf, Christian.; Ott, Ricardo.; Ramírez, Martín J.; Raven, Robert J.; Rheims, Cristina A.; Ruiz, Gustavo R. S.; Santos, Adalberto J.; Saucedo, Alma D.; Sierwald, Petra.; Szűts, Tamás.; Ubick, Darrell.; Wang, Xin-Ping.Based on a survey of a wide variety of oonopid genera and outgroups, we hypothesize new synapomorphies uniting the Oonopidae (minus the South African genus Calculus Purcell, which is transferred to the Orsolobidae). The groundplan of the tarsal organ in Oonopidae is hypothesized to be an exposed organ with a distinctive, longitudinal ridge originating from the proximal end of the organ, and a serially dimorphic pattern of 4-4-3-3 raised receptors on legs I-IV, respectively. Such organs typify the diverse, basal, and ancient genus Orchestina Simon. Several other genera whose members resemble Orchestina in retaining two plesiomorphic features (an H-shaped, transverse eye arrangement and a heavily sclerotized, thick-walled sperm duct within the male palp) are united by having tarsal organs that are partly (in the case of Cortestina Knoflach) or fully capsulate (in the case of Sulsula Simon, Xiombarg Brignoli, and Unicorn Platnick and Brescovit). The remaining oonopids are united by the loss of the heavily sclerotized palpal sperm duct, presumably reflecting a significant transformation in palpal mechanics. Within that large assemblage, a 4-4-3-3 tarsal organ receptor pattern and an H-shaped eye arrangement seem to be retained only in the New Zealand genus Kapitia Forster; the remaining genera are apparently united by a reduction in the tarsal organ pattern to 3-3-2-2 raised receptors on legs I-IV and by the acquisition of a clumped eye arrangement. Three subfamilies of oonopids are recognized: Orchestininae Chamberlin and Ivie (containing only Orchestina; Ferchestina Saaristo and Marusik is placed as a junior synonym of Orchestina), Sulsulinae, new subfamily (containing Sulsula, Xiombarg, Unicorn, and Cortestina), and Oonopinae Simon (containing all the remaining genera, including those previously placed in the Gamasomorphinae). The type species of Sulsula and Kapitia, S. pauper (O. P.-Cambridge) and K. obscura Forster, are redescribed, and the female of S. pauper is described for the first time. A new sulsuline genus, Dalmasula, is established for Sulsula parvimana Simon and four new species from Namibia and South Africa. ItemTaxonomy and phylogenetics of Nanometinae and other Australasian orb-weaving spiders (Araneae, Tetragnathidae). (Bulletin of the American Museum of Natural History, no. 438)(American Museum of Natural History., 2020-02-28) Alvarez-Padilla, Fernando.; Kallal, Robert J., 1987-; Hormiga, Gustavo.The spider family Tetragnathidae Menge is a cosmopolitan, relatively well-studied spider clade with some members readily identifiable by their elongate chelicerae and/or their horizontal orb webs. It has four recognized subfamilies--Tetragnathinae, Metainae, Leucauginae, and the Australasian endemic Nanometinae--although many genera remain unassigned to subfamilial groups. Nanometinae alpha taxonomy is the least well understood of these lineages despite the inclusion of members of the subfamily in a number of phylogenetic analyses over the past decade. Here we describe 10 new species and revise seven additional tetragnathids from Australia, New Zealand, New Caledonia, and Papua New Guinea in the genera Nanometa, Taraire, gen. nov., Tawhai, gen. nov., Harlanethis, gen. nov., and Iamarra, gen. nov. These 17 species are: Nanometa gentilis Simon, 1908, N. trivittata (Keyserling, 1887), comb. nov., N. sarasini (Berland, 1924), comb. nov., N. lagenifera (Urquhart, 1888), comb. nov., N. purpurapunctata (Urquhart, 1889), comb. nov., N. fea, sp. nov., N. tasmaniensis, sp. nov., N. tetracaena, sp. nov., N. dimitrovi, sp. nov., N. dutrorum, sp. nov., N. forsteri, sp. nov., Taraire rufolineata (Urquhart, 1889), comb. nov., Taraire oculta, sp. nov., Tawhai arborea (Urquhart, 1891), comb. nov., Harlanethis lipscombae, sp. nov., H. weintrauborum, sp. nov., and Iamarra multitheca, sp. nov. We also synonymize Nediphya Marusik and Omelko, 2017, and the monotypic genus Eryciniolia Strand, 1912, with Nanometa, bringing the total number of species in the genus from one to 14. Using an expanded taxon sampling for prior studies based on six molecular markers--12S rRNA, 16S rRNA, 18S rRNA, 28S rRNA, cytochrome c oxidase subunit I, and histone H3--and both maximum likelihood and Bayesian methods, we place these taxa in the tetragnathid tree of life. Nanometinae and its constituent genera Nanometa and Pinkfloydia are reciprocally monophyletic. Harlanethis belongs to Leucauginae. The genera Taraire, Tawhai, and Iamarra defy robust phylogenetic placement and are not yet assigned to subfamily. ItemUltrastructure of the spermatozoa in the spider genus Pimoa : new evidence for the monophyly of Pimoidae plus Linyphiidae (Arachnida, Araneae). (American Museum novitates, no. 3682)(New York, NY : American Museum of Natural History., 2010) Michalik, Peter, 1976-; Hormiga, Gustavo.The spermatozoa of spiders (Araneae) show a high structural diversity, resulting in several potential phylogenetic characters. In the present paper, we describe the spermatozoa of the spider family Pimoidae for the first time. We investigate four species of the genus Pimoa (P. altioculata, P. curvata, P. laurae, and P. edenticulata) by means of light and transmission electron microscopy. The male reproductive system consists of paired testes and long convoluted paired deferent ducts. The spermatozoa are generally characterized by: (1) a cylindrical acrosomal vacuole, (2) an acrosomal filament restricted to the precentriolar part of the nucleus, (3) a nuclear canal running in the periphery but projecting towards the posterior portion of the nucleus, (4) a short postcentriolar elongation of the nucleus, (5) a 9+0 axonemal pattern, and (6) cleistospermia as transfer form. The organization of the axoneme is of particular phylogenetic interest, since a 9+0 axonemal pattern was described within spiders only for the megadiverse family Linyphiidae, the sister group of Pimoidae. We have reconstructed the evolution of the axoneme using comparative spermatozoal data for 54 orbicularian species representing 11 families. We propose that the 9+0 axonemal pattern is a new synapomorphy for Pimoidae + Linyphiidae. The phylogenetic and evolutionary implications of other potential sperm characters (e.g., length of the postcentriolar elongation of the nucleus) are discussed.