40 resultados para Jacobian arithmetic, genus 2

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo


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Polychlorinated biphenyls (PCBs) and organochlorine pesticides are compounds that do not occur naturally in the environment and are not easily degraded by chemical or microbiological action. In the present work, those compounds were analysed in unhatched penguin eggs and whole krill collected in Admiralty Bay, King George Island, Antarctica in the austral summers of 2004-2005 and 2005-2006. The compounds found in higher levels (in a wet weight basis) were, in most of the egg samples, the PCBs (2.53-78.7 ng g(-1)), DDTs (2.07-38.0 ng g(-1)) and HCB (4.99-39.1 ng g(-1)) and after Kruskal-Wallis ANOVA, the occurrence seemed to be species-specific for the Pygoscelis genus. In all of the cases, the levels found were not higher than the ones in Arctic birds in a similar trophic level. The krill samples analysis allowed estimating the biomagnification factors (which resulted in up to 363 for HCB, one order of magnitude higher than DDTs and chlordanes and two orders of magnitude higher than the other groups) of the compounds found in eggs, whose only source of contamination is the female-offspring transfer. (C) 2009 Elsevier Ltd. All rights reserved.

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A new myrmicine ant, Tropidomyrmex elianae gen. n. & sp. n., is described from southeastern and central Brazil, based on workers, ergatoid gynes, males and larvae. Tropidomyrmex workers are relatively small, monomorphic, characterized mainly by the feebly pigmented and extremely thin integument; subfalcate mandibles bearing a single apical tooth; palpal formula 1,2; clypeus relatively broad and convex; reduced compound eyes; propodeum unarmed and with a strongly medially depressed declivous face; double and bilobed well developed subpostpetiolar processes; and peculiarities in the sting apparatus. A colony fragment of T. elianae containing workers, ergatoid gynes, males, and brood was found inside a ground termite nest (Anoplotermes pacificus Apicotermitinae) in a montane rocky scrubland in the state of Minas Gerais, southeastern Brazil. Tropidomyrmex elianae is known also from two workers collected in leaf litter samples processed with a Winkler extractor, from the state of Tocantins, central-north Brazil. Despite the differences from the accepted solenopsidine genera, Tropidomyrmex is tentatively assigned to this tribe. Within the solenopsidine ants, the genus is apparently related to Tranopelta. Tropidomyrmex is marked by extreme reductions, perhaps reflecting adaptations to particular habits and habitats.

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The Neotropical ant genus Lachnomyrmex Wheeler, 1910 is revised for the first time. A revised generic description is provided for workers and gynes; males remain unknown. Morphological patterns combined with geographical data led to the recognition of 16 species, of which 10 are here described as new: L. amazonicus sp. n., L. fernandezi sp. n., L. grandis Fernandez & Baena, L. haskinsi Smith, L. lattkei sp. n., L. longinodus Fernandez & Baena, L. longinoi sp. n., L. mackayi sp. n., L. nordestinus sp. n., L. pilosus Weber, L. laticeps sp. n., L. platynodus sp. n., L. plaumanni Borgmeier, L. regularis sp. n., L. scrobiculatus Wheeler, and L. victori sp. n. The gynes of L. grandis, L. haskinsi, and L. pilosus are described for the first time. Illustrated identification keys for workers, distribution maps, and high resolution illustrations are supplied for all species. Some Lachnomyrmex species are relatively common in the leaf-litter of submontane wet forests in Central and South America; others remain known by very few individuals. The relatively small and apparently monogynic Lachnomyrmex colonies inhabit small nests in the ground, among rotten leaves and inside fallen logs. Workers generally forage alone on the ground or within the leaf litter, but have been recorded also on tree trunks, and apparently do not recruit nestmates.

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Trichomycterus crassicaudatus is described as a new species from the Rio Iguacu basin in southern Brazil. The new species has an exceptionally deep posterior region of the body (caudal peduncle depth 22.8-25.4% SL), resulting in an overall shape which distinguishes it at once from all other members of the Trichomycteridae. The caudal fin of the species is broad-based and forked, a shape also distinguishing it from all other species in the family. A number of autapomorphic modifications of T. crassicaudatus are associated with the deepening of the caudal region, including an elongation of the hemal and neural spines of the vertebrae at the middle of the caudal peduncle. Phylogenetic relationships of the new species are yet unresolved, but it shares a similar color pattern and a thickening of caudal-fin procurrent rays with T. stawiarski, a poorly-known species also from the Rio Iguacu basin. Coloration and body shape also include similarities with T. lewi from Venezuela.

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A new species of the thorny catfish genus Leptodoras (family Doradidae) is described. The new species shares three characters with its congeners, the modified oral hood with distinct upper labial extensions, the first gill arch with enlarged accessory lamellae extending well onto medial face of gill filaments, and the pelvic fin inserted in anterior half of body. The new species is distinguished from congeners by having a large dark submarginal blotch on distal half of dorsal-fin spine and anteriormost dorsal-fin branched rays, lower labial extension of modified oral hood extending more posteriorly than upper labial extension, relatively few midlateral scutes, gas bladder moderately sized (not reduced), paired bony capsules on anteriormost vertebrae reduced to paired cup-like laminar ossifications separated by a triangular septum, pair of small, swelling-like diverticula on each side of the anterior chamber of gas bladder, a well-developed anterior nuchal plate, and nuchal foramina present. The new species was discovered from a single specimen collected in the rio Fresco, a tributary of the rio Xingu, and is described based on this and on additional material recently collected in the same area. A discussion of its placement within Leptodoras is also presented.

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A revision of the deep-water verticordiid genus Spinosipella is provided, based on conchological and anatomical characters. The genus is considered distinct from Verticordia (of which it was considered a subgenus) based on the strong ribs, prickly surface, reduction of lunula, relative large size, weakly spiral valve shape, and other characters. The following species are considered in the genus: (1) Spinosipella agnes new species, ranging from Florida, USA, to Rio de Janeiro, Brazil, and also including the Porcupine Abyssal Plain in the North Atlantic; (2) S. tinga new species, occurring from Rio de Janeiro to Rio Grande do Sul, Brazil; (3) S. acuticostata (Philippi, 1844), a Pliocene fossil from southern Italy; (4) S. deshayesiana (Fischer, 1862), from south and central Indo-Pacific (S. ericia Hedley, 1911, the type species of the genus, was revealed to be a new synonym of S. deshayesiana); and (5) S. costeminens (Poutiers, 1981), from the tropical west Pacific. The five species differ mainly in conchological details of the number and size of ribs, of the prickly sculpture, shape of the shell, of the hinge and the degree of convexity. Anatomical description is also provided for the two Pacific species, which differ among themselves mainly by the size of the pair of renal folds. From the standpoint of anatomical characters, the more significant are: the wide lithodesma; the elongation of the auricles, crossing the roof of pallial cavity; a tall digital fold in posterior region of supraseptal chamber; the low but wide palps; the muscular, gizzard-like stomach; the complete separation of both constituents of the hermaphroditic gonad (a ventro-posterior testicle and a centro-dorsal ovary), and a complete fusion of the visceral ganglia.

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Liosomadoras Fowler, 1940 includes two nominal species: L. oncinus, described from the rio Negro in Brazil, and L. morrowi described from the Peruvian Amazon. Both species are known from only few specimens deposited in fish collections, and information on these fishes is scarce. In order to rectify this situation, diagnoses of the genus and its species and an osteological description off.. oncinus are presented based on recently collected specimens. In addition, the taxonomy of the species of Liosomadoras is reviewed, and L. morrowi is confirmed as distinct from L. oncinus, and also distributed in the Brazilian Amazon. Liosomadoras is hypothesized as a relatively basal genus within Auchenipterinae, sister to all other species of the group, except Asterophysus batrachus and Tocantinsia piresi.

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The freshwater prawns of the genus Macrobrachium Spence Bate, 1868 are widely distributed in rivers of tropical and subtropical regions and represent an interesting group with controversial taxonomy. The morphological characters traditionally used to separate species have shown a high intraspecific variation. Doubts about the status of M. birai Lobao, Melo & Fernandes, 1986, M. holthuisi Genofre & Lobao, 1978 and M. petronioi Melo, Lobao & Fernandes, 1986 have been arisen due to the high resemblance of the former two species with M. olfersi (Wiegmann, 1836), and the latter one with M. potiuna (Muller, 1880). Therefore, we performed a detailed morphological analysis of these species, including new characters not usually used in the species recognition. The present results here with molecular data lead us to conclude that M. birai and M. holthuisi are junior synonyms of M. olfersi, and M. petronioi is a junior synonym of M. potiuna. Considering these synonymies, 17 valid species are now reported for the Brazilian territory.

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A taxonomic study on the South American dwarf boas of the genus Tropidophis revealed the existence of two new species in the Atlantic Forest bionic. As a result, we recognize five mainland species, three in the Atlantic Forest and two in northwestern South America. Based on general distribution and morphological orientation, the type locality of T. paucisquamis is restricted to Estacao Biologica de Boraceia (EBB), municipality of Salesopolis, state of Sao Paulo, Brazil; furthermore, a lectotype for T. taczanowskyi is designated. We provide data on the hemipenial morphology of two South American Tropidophis, showing that the quadrifurcate condition described for West Indian taxa also occurs in mainland congeners. The distributions of the three Atlantic Forest species are congruent with patterns of diversification of other vertebrate taxa associated with cold climates prevalent at high elevations. Refugial isolation and riverine barriers may account for such speciation events.

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Currently, five genera are assigned to red seaweeds of the Laurencia complex worldwide: Chondrophycus, Laurencia s.s., Osmundea, Palisada and Yuzurua. The genera are segregated on the basis of morphological characters, especially the reproductive traits, and molecular sequences of the plastid-encoded gene rbcL. Four of the genera have been resolved as monophyletic, but not Laurencia s.s. In this study based on an rbcL gene phylogeny we show the presence of a sixth lineage within the Laurencia complex, viz., Laurencia marilzae plus two unidentified species of Laurencia from Brazil. The phylogenetic position of this group, combined with the high genetic divergence from Laurencia s.s. (8.2-11%), strongly support the establishment of a sixth genus for the complex, proposed here as Laurenciella gen. nov. This new taxon differs from Laurencia s.s. and from the other genera of the complex by molecular sequence data, but is indistinguishable from Laurencia s.s. by the usual morphological features.

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Male secondary sexual characters in Lepidoptera may be present or absent in species that otherwise appear to be closely related, an observation that has led to differences of opinion over the taxonomic usefulness of these structures above the species level. An evolutionary issue raised by this debate is whether male secondary sexual characters (1) can be regained after being lost evolutionarily, (2) are not lost after being evolved, or (3) are 'switched on and off' by genes that regulate development. A second evolutionary issue is the conditions under which male secondary sexual characters might be lost or gained evolutionarily. Because these structures are thought to promote species recognition, theory predicts evolutionary losses to be most likely in allopatry; evolutionary gains to be most likely during the process of secondarily establishing sympatry or during sympatric speciation. We updated the species-level taxonomy of the brilliant emerald winged Neotropical lycaenid butterfly genus Arcas and performed an analysis of phylogenetic relations among species to assess these evolutionary issues. We morphologically detail a scent pouch on the ventral hindwing of Areas and report that six species possess the pouch with androconia, one possesses the pouch without androconia, and the remaining two species have neither pouch nor androconia. In addition, eight Areas species have a morphologically species-specific male forewing scent pad, and one lacks a scent pad. This variation appears to be the result of three evolutionary losses and no gains of male secondary sexual organs. The four Areas species lacking a scent pouch or a scent pad are allopatric with their closest phylogenetic relatives while four of five with both of these structures are sympatric. Although Arcas is a small genus, these results are significantly more extreme than predicted by chance. For taxonomy, this study provides a rationale for the evolutionary loss of male secondary sexual structures and suggests that their absence, but itself, does not indicate a lack of relationship above the species level.

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We reviewed several large collections of the genus Hypostomus from the rio Iguacu basin summing up to 793 specimens mainly from the Laboratorio de Ictiologia do Departamento de Ecologia e Biologia Evolutiva from Universidade Federal de Sao Carlos, from fish collection of Nucleo de Pesquisas em Limnologia, Ictiologia e Aquicultura da Universidade Estadual de Maringa, and from the Museu de Historia Natural do Capao da Imbuia. Hypostomus albopunctatus, H. commersoni, H. derbyi, and H. myersi are redescribed and Hypostomus nigropunctatus is described as a new species. A practical key for identification of Hypostomus species from the rio Iguacu is also provided.

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We revisit species diversity within Oreobates (Anura: Strabomantidae) by combining molecular phylogenetic analyses of the 16S rRNA amphibian barcode fragment with the study of the external morphology of living and preserved specimens. Molecular and morphological evidence support the existence of 23 species within Oreobates, and three additional candidate species (Oreobates sp. [Ca JF809995], Oreobates sp. [Ca EU368903], Oreobates cruralis [Ca EU192295]). We describe and name three new species from the Andean humid montane forests of Departamento Cusco, southern Peru: O. amarakaeri New Species from Rio Nusinuscato and Rio Mabe, at elevations ranging from 670 to 1000 m in the Andean foothills; O. machiguenga, new species, from Rio Kimbiri (1350 m), a small tributary of the Apurimac River, in the western versant of Cordillera Vilcabamba; and O. gemcare, new species, from the Kosnipata Valley at elevations ranging from 2400 to 2800 m. The three new species are readily distinguished from all other Oreobates by at least one qualitative morphological character. Three species are transferred to Oreobates from three genera of Strabomantidae: Hypodactylus lundbergi, Pristimantis crepitans, and Phrynopus ayacucho (for which the advertisement call, coloration in life, and male characteristics are described for first time). Oreobates simmonsi is transferred to the genus Lynchius. Hylodes verrucosus is considered a junior synonym of Hylodes philippi. In addition, H. philippi is removed from the synonymy of O. quixensis and considered a nomem dubium within Hypodactylus. The inclusion of Phrynopus ayacucho in Oreobates extends the ecological range of the genus to the cold Andean puna. Oreobates is thus distributed from the Amazonian lowlands in southern Colombia to northern Argentina, reaching the Brazilian Atlantic dry forests in eastern Brazil, across an altitudinal range from ca. 100 to 3850 m.

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Redescriptions of Bizarrifrons magus (Nitzsch [in Giebel], 1866), the type species of Bizarrifrons, and B. picturatus Carriker & Diaz-Ungria, 1961 are given based on material from their type hosts. The nymphal instars of these two species are described and illustrated for the first time. Also, three new species are named and described: B. latifrons, from the russet-backed oropendola, Psarocolius angustifrons alfredi (Des Murs, 1856); B. wecksteini, from the Amazonian oropendola, Psarocolius b. bifasciatus (Spix, 1824); and B. quasisymmetricus, from the solitary cacique, Cacicus solitarius (Vieillot, 1816) (Passeriformes: Icteridae). Two species-groups are proposed, and a checklist and a key for the species of Bizarrifrons are also included. Sequences of a portion of the mitochondrial cytochrome oxidase I (COI) and the nuclear elongation factor 1 alpha (EF-1 alpha) genes for two species are given for the first time in this genus.