Revisão da taxonomia e distribuição do gênero Trechona C. L. Koch, 1850 (Arachnida: Araneae: Dipluridae)

• Autor(a) principal: Pedroso, Denis Rafael
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2228
• topic: Sistemática de Araneae; Biodiversidade tropical; Taxonomia de Dipluridae; Araneae systematic; Tropical biodiversity; Dipluridae taxonomy; CNPQ::CIENCIAS BIOLOGICAS::ZOOLOGIA::TAXONOMIA DOS GRUPOS RECENTES

Trechona C. L. Koch, 1850 is a Neotropical genus of Mygalomorphae, formed by large spiders (body size up to 5 cm). Its species have a well-developed lyra at the internal side of the maxilla of the pedipalps. The lyra is composed by a large number of rigid setae of different sizes, clubbed or not, arranged in several rows. Most diplurid have no lyra at all. The only other lyrate diplurid, Diplura C. L. Koch, 1850, bear only up to 26 clavate setae, arranged in one row on the maxilla. Besides, Trechona usually has relatively short spinnerets compared to the long ones of other diplurids. These spiders have a brownish to blackish body, usually with a zebrate pattern of light, transverse stripes on the abdomen. They live in long burrows on ravines and under logs or stones at the forest soil. Though common spiders on Atlantic Forest, Trechona specimens are not easily collected, due to their burrowing habits and the arduous effort needed to take them out of their burrows. Up to the beginning of this dissertation, six species and one subspecies are included on Trechona, and its distribution area included Brazil, Guyanas and Colombia. As result of this revision, the genus composition and distribution were deeply changed. T. lycosiformis (C. L. Koch, 1842) was transferred to Theraphosidae incertae sedis, under the new combination "Avicularia" lycosiformis. The only Colombian species, T. sericata Karsch, 1879, was transferred to Linothele Karsch, 1879. T. adspersa Bertkau, 1880, from Rio de Janeiro state, was transferred to Nemesiidae and respresents one of the species of an undescribed genus from Southeastern Brazil. The only species remaining in Trechona are restricted to the Atlantic Forest of Brazil, as the Amazonian and Guyanan records for T. venosa (Latreille, 1832) are clearly misidentifications. T. venosa is the type species of the genus and occurs from Rio de Janeiro city to central-north Espírito Santo state. T. rogenhoferi (Ausserer, 1871) is a nomen dubium, based on an unidentifiable juvenile. T. rufa Vellard, 1924 is raised to species rank. T. uniformis Mello-Leitão, 1935 is a valid species, found in the eastern coast of São Paulo (no specific locality cited in the original description), southern Minas Gerais, and, probably, southwestern Rio de Janeiro states. It belongs to a separate group of species, with a very long bulb and a very elongate spermatheca, without lateral lobe and a clear fundus. Three undescribed species were found: Trechona sp. 1 - only females, from Santa Catarina state; Trechona sp. 2 - only a male, from Caparaó National Park, Minas Gerais state; and Trechona sp. 3 - a male and a juvenile, from Cotia and Santo André, both in São Paulo state. A key for species identification is included.