24 resultados para Neotropics
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo
Resumo:
Buteonine hawks represent one of the most diverse groups in the Accipitridae, with 58 species distributed in a variety of habitats on almost all continents. Variations in migratory behavior, remarkable dispersal capability, and unusual diversity in Central and South America make buteonine hawks an excellent model for studies in avian evolution. To evaluate the history of their global radiation, we used an integrative approach that coupled estimation of the phylogeny using a large sequence database (based on 6411 bp of mitochondrial markers and one nuclear intron from 54 species), divergence time estimates, and ancestral state reconstructions. Our findings suggest that Neotropical buteonines resulted from a long evolutionary process that began in the Miocene and extended to the Pleistocene. Colonization of the Nearctic, and eventually the Old World, occurred from South America, promoted by the evolution of seasonal movements and development of land bridges. Migratory behavior evolved several times and may have contributed not only to colonization of the Holarctic, but also derivation of insular species. In the Neotropics, diversification of the buteonines included four disjunction events across the Andes. Adaptation of monophyletic taxa to wet environments occurred more than once, and some relationships indicate an evolutionary connection among mangroves, coastal and varzea environments. On the other hand, groups occupying the same biome, forest, or open vegetation habitats are not monophyletic. Refuges or sea-level changes or a combination of both was responsible for recent speciation in Amazonian taxa. In view of the lack of concordance between phylogeny and classification, we propose numerous taxonomic changes. (C) 2009 Elsevier Inc. All rights reserved.
Resumo:
Obtusitermes Snyder is a genus endemic to the Neotropics, restricted to northern South America and southern Central America. Obtusitermes panamae Snyder was described from Quipo, Panama. Herein, we describe Obtusitermes formosulus, n. sp., from Venezuela and Trinidad and Tobago, based on the dimorphic soldier and polymorphic worker. These descriptions provide strong evidence that Parvitermes bacchanalis Mathews should not be included in Obtusitermes.
Resumo:
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.
Resumo:
Pseudolithoxus kelsorum is described as a new species based on type material from the upper Orinoco in Amazonas State, Venezuela. Pseudolithoxus kelsorum is diagnosed from all other Pseudolithoxus by having dark brown to black base color with eight to 11 (usually nine) light yellow vertical or oblique transversal bands between orbits and caudal fin, bands wide and rarely but sometimes incomplete or contorted as swirls (vs. dark brown to black base color with 18 or more thin, light yellow, frequently contorted transversal bands between orbits and caudal fin in P. tigris; black base color with small white spots in P. anthrax and P. nicoi; and light brown base color with dark brown to black spots in P. dumus). Distributions of P. kelsorum and other Ancistrini taxa support the presence of a zoogeographic filter limiting fish distributions across a reach of the Orinoco River between the Ventuari-Orinoco confluence and the Maipures rapids.
Resumo:
A comprehensive new inventory of Brazilian plants and fungi was published just in time to meet a 2010 Convention on Biological Diversity target and offers important insights into this biodiversity's global significance. Brazil is the home to the world's richest flora (40,989 species; 18,932 endemic) and includes two of the hottest hotspots: Mata Atlantica (19,355 species) and Cerrado (12,669 species). Although the total number of known species is one-third lower than previous estimates, the absolute number of endemic vascular plant species is higher than was previously estimated, and the proportion of endemism (56%) is the highest in the Neotropics. This compilation serves not merely to quantify the scale of the challenge faced in conserving Brazil's unique flora but also serves as a key resource to direct action and monitor progress. Similar efforts by other megadiverse countries are urgently required if the 2020 targets of the Convention on Biological Diversity and the Global Strategy for Plant Conservation are to be attained.
Resumo:
Populations of Synchaeta jollyae (Shiel & Koste, 1993) (Rotifera), a species recently recorded for the first time in Brazil and South America, were analyzed in reservoirs in Southeast Brazil. Sampling was carried out monthly from August 2006 to July 2007 at Furnas Reservoir in the Rio Grande basin, state of Minas Gerais, and in four cascade reservoirs in the Tiete River basin (Barra Bonita, Bariri, Ibitinga and Nova Avanhandava) state of Sao Paulo, in June and September 2008 and in January and May 2009. Synchaeta jollyae occurred in most samples and periods. From the results obtained it is evident that S. jollyae occurs in water bodies of varied trophic status but reaches larger populations in eutrophic water bodies and during lower temperature periods. The greatest densities of S. jollyae were found in the eutrophic Bariri Reservoir, on the Tiete River, during the winter. Mann-Whitney test confirmed the significant difference between the population densities in periods of high and low temperatures, with populations reaching higher densities at lower temperatures. It is not yet possible to tell whether S. jollyae is a widely distributed species that has been overlooked in previous plankton studies in South America. Wherever these populations of S. jollyae might have originated, it appears to be a species well established and adapted to a wide range of conditions in the Neotropics.
Resumo:
As part of an ongoing revision of the family Gonyleptidac, we have identified many species that are synonyms of previously described species or misplaced in this family. This article summarizes these findings, adding previously unavailable information or correcting imprecise observations to justify the presented taxonomic changes. The following new familial or subfamilial assignments are proposed: Nemastygnus Roewer, 1929 and Taulisa Roewer, 1956 are transferred to Agoristenidae, Agoristeninae; Napostygnus Roewer, 1929 to Cranaidae; Ceropachylinus peruvianus Roewer, 1956 and Pirunipygus Roewer, 1936 are transferred to Gonyleptidae, Ampycinae; Gyndesops Roewer, 1943, Haversia Roewer, 1913 and Oxapampeus Roewer, 1963 are transferred to Gonyleptidae, Pachylinae. The following generic synonymies are proposed for the family Gonyleptidae: Acanthogonyleptes Mello-Leitao, 1922 = Centroleptes Roewer, 1943; Acrographinotus Roewer, 1929 = Unduavius Roewer, 1929; Gonyleptes Kirby, 1819 = Collonychium Bertkau, 1880; Mischonyx Bertkau, 1880 = Eugonyleptes Roewer, 1913 and Gonazula Roewer, 1930; Parampheres Roewer, 1913 = Metapachyloides Roewer, 1917; Pseudopucrolia Roewer, 19 12 = Meteusarcus Roewer, 1913; Haversia Roewer, 19 13 = Hoggellula Roewer, 1930. The following specific synonymies are proposed for the family Gonyleptidae: Acanthogonyleptes singularis (Mello-Leitao, 1935) = Centroleptes flavus Roewer, 1943, syn. n.; Geraeocormobius sylvarum Holmberg, 1887 = Discocyrtus serrifemur Roewer, 1943, syn. n.; Gonyleptellus bimaculatus (Sorensen, 1884) = Gonyleptes cancellatus Roewer, 1917, syn. n.; Gonyleptes atrus Mello-Leitao, 1923 = Weyhia brieni Giltay, 1928, syn. n.; Gonyleptes fragilis Mello-Leitao, 1923 = Gonyleptes banana Kury, 2003, syn. n.; Gonyleptes horridus Kirby, 1819 = Collonychium bicuspidatum Bertkau, 1880, syn. n., Gonyleptes borgmeyeri Mello-Leitao, 1932, syn. n., Gonyleptes curvicornis Mello-Leitao, 1932, syn. n., Metagonyleptes hamatus Roewer, 1913, syn. n. and Paragonyleptes simoni Roewer, 1930, syn. n.; Gonyleptes pustulatus Sorensen, 1884 = Gonyleptes guttatus Roewer, 1917, syn. n.; Haversia defensa (Butler, 1876) = Sadocus vallentini Hogg, 1913, syn. n.; Liogonyleptoides minensis (Piza, 1946) = Currala bahiensis Soares, 1972, syn. n.; Megapachylus grandis Roewer, 1913 = Metapachyloides almeidai Soares & Soares, 1946, syn. n.; Mischonyx cuspidatus (Roewer, 1913) = Gonazula gibbosa Roewer, 1930 syn. n.; Mischonyx scaber (Kirby, 1819) = Xundarava holacantha Mello-Leitao, 1927, syn. n.; Parampheres tibialis Roewer, 1917 = Metapachyloides rugosus Roewer, 1917, syn. n.; Parapachyloides uncinatus (Sorensen, 1879) = Goyazella armata Mello-Leitao, 1931, syn. n.; Pseudopucrolia mutica (Perry, 1833) = Meteusarcus armatus Roewer, 1913, syn. n. The following new combinations are proposed: Acrographinotus ornatus (Roewer, 1929), comb. n. (ex Unduavius); Gonyleptellus bimaculatus (Sorensen, 1884), comb. n. (ex Gonyleptes); Gonyleptes perlatus (Mello-Leitao, 1935), comb. n. (ex Moojenia); Mischonyx scaber (Kirby, 1819), comb. n. (ex Gonyleptes); and Neopachyloides peruvianus (Roewer, 1956), comb. n. (ex Ceropachylus). The following species of Gonyleptidae, Gonyleptinae are revalidated: Gonyleptes atrus Mello-Leitao, 1923 and Gonyleptes curvicornis (Roewer, 1913).
Resumo:
Behavioral data on Neotropical coenagrionids is still scanty, with very few studies on their reproductive behavior. Here we present the first description of the reproductive behavior of A. truncatum in a high density population in the Brazilian Neotropical savanna. The observations were made at a pond in an ecological reserve. Males remain at the water searching for females. Females remain in the surrounding vegetation and only approach the water to mate and oviposit. The mean duration of copulation was 25.6 +/- 3.26 minutes. Copulations are concentrated between 12:00 and 14:00 h (71%). Females oviposit in tandem with males, sometimes submerging to oviposit. Oviposition took 43.08 +/- 22.17 minutes. Female underwater oviposition seems to disrupt male guarding and females emerge from the water by themselves. Malemale interactions usually consist of chases and facing off. This damselfly species is apparently non-territorial, since males did not defend resources and searched for females in the area.
Resumo:
We propose a stage-structured integrodifference model for blowflies' growth and dispersion taking into account the density dependence of fertility and survival rates and the non-overlap of generations. We assume a discrete-time, stage-structured, model. The spatial dynamics is introduced by means of a redistribution kernel. We treat one and two dimensional cases, the latter on the semi-plane, with a reflexive boundary. We analytically show that the upper bound for the invasion front speed is the same as in the one-dimensional case. Using laboratory data for fertility and survival parameters and dispersal data of a single generation from a capture-recapture experiment in South Africa, we obtain an estimate for the velocity of invasion of blowflies of the species Chrysomya albiceps. This model predicts a speed of invasion which was compared to actual observational data for the invasion of the focal species in the Neotropics. Good agreement was found between model and observations.
Resumo:
In the present study, mitochondrial (mt)DNA sequence data were used to examine the genetic structure of fire-eye antbirds (genus Pyriglena) along the Atlantic Forest and the predictions derived from the river hypothesis and from a Last Glacial Maximum Pleistocene refuge paleomodel were compared to explain the patterns of genetic variation observed in these populations. A total of 266 individuals from 45 populations were sampled over a latitudinal transect and a number of phylogeographical and population genetics analytical approaches were employed to address these questions. The pattern of mtDNA variation observed in fire-eye antbirds provides little support for the view that populations were isolated by the modern course of major Atlantic Forest rivers. Instead, the data provide stronger support for the predictions of the refuge model. These results add to the mounting evidence that climatic oscillations appear to have played a substantial role in shaping the phylogeographical structure and possibly the diversification of many taxa in this region. However, the results also illustrate the potential for more complex climatic history and historical changes in the geographical distribution of Atlantic Forest than envisioned by the refuge model. (c) 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105, 900824.
Resumo:
A new species of Mezilaurus from Colombia is described and illustrated in this paper. This species, Mezilaurus introrsa, is so far only known from the Ecological Station of Caparu in southeastern Colombia, Vaupes state, where it occurs in seasonally inundated forest, locally called "igapo".
Resumo:
Five new species are described herein for the Neotropical genus Psilochlorops, up to now known only from the type-species, P. clavitibia Duda-P. brunneus sp. n., P. elongatum sp. n., P. flavisoma sp. n., P. nigrifemur sp. n. and P. paganelliae sp. n. All new species are described in detail and illustrated. A key to the species of the genus is provided. The diagnosis of Psilochlorops, after the addition of these species, is emended. A cladistic analysis of the genus indicates that Psilochlorops is monophyletic and show the affinities between the species.
Resumo:
The Neotropical tribe Trimezieae are taxonomically difficult. They are generally characterized by the absence of the features used to delimit their sister group Tigridieae. Delimiting the four genera that make up Trimezieae is also problematic. Previous family-level phylogenetic analyses have not examined the monophyly of the tribe or relationships within it. Reconstructing the phylogeny of Trimezieae will allow us to evaluate the status of the tribe and genera and to examine the suitability of characters traditionally used in their taxonomy. Maximum parsimony and Bayesian phylogenetic analyses are presented for 37 species representing all four genera of Trimezieae. Analyses were based on nrITS sequences and a combined plastid dataset. Ancestral character state reconstructions were used to investigate the evolution of ten morphological characters previously considered taxonomically useful. Analyses of nrITS and plastid datasets strongly support the monophyly of Trimezieae and recover four principal clades with varying levels of support; these clades do not correspond to the currently recognized genera. Relationships within the four clades are not consistently resolved, although the conflicting resolutions are not strongly supported in individual analyses. Ancestral character state reconstructions suggest considerable homoplasy, especially in the floral characters used to delimit Pseudotrimezia. The results strongly support recognition of Trimezieae as a tribe but suggest that both generic- and species-level taxonomy need revision. Further molecular analyses, with increased sampling of taxa and markers, are needed to support any revision. Such analyses will help determine the causes of discordance between the plastid and nuclear data and provide a framework for identifying potential morphological synapomorphies for infra-tribal groups. The results also suggest Trimezieae provide a promising model for evolutionary research.
Resumo:
Currently the genus Corynoneura Winnertz comprises 10 species already cited or described for the Neotropical region. In the present paper 15 new species are described for the Neotropics: 12 new species are described from Brazil, five of them are described as male, female, pupa and larva, Corynoneura canchim sp. n., C. diogo sp. n., C. espraiado sp. n., C. humbertoi sp. n., C. salviniatilis sp. n.; three as male, pupa and larva, C. franciscoi sp. n.; C. longiantenna sp. n. and C. renata sp. n.; the species C. sisbiota sp. n. as male, female and pupa; C. bodoquena sp. n. as male and pupa and C. boraceiasp. n. and C. vidiapodeme sp. n. as males. Corynoneura trondi sp. n. is described from Chile (male, pupa), C. guanacaste sp. n. from Costa Rica (male) and C. zempoala sp. n. from Mexico (male). The knowledge of the distribution of Corynoneura fortispicula, C. sertaodaquina, C. septadentata and C. unicapsulata all species described by Wiedenbrug and Trivinho-Strixino (2011) as well as Corynoneura ferelobata Sublette et Sasa is extended. A larval morphotype is also included. Keys for males, females, pupae and larvae to known species of the Neotropical Corynoneura are given.
Resumo:
Paraleia was originally described by Tonnoir for P. fulvescens, known from Australia. More recently, eleven Neotropical species were added to the genus-nine of which are from Chile and southern Argentina, one from Bolivia, and one from Peru. This distribution pattern is typical of many mycetophilid genera. Six new Neotropical species of Paraleia from the Andean Colombia and Ecuador are herein described. Male terminalia of P. bolivari sp. n., P. denticulata sp. n., P. fumosa sp. n., and P. tonnoiri sp. n., as well as female terminalia of P. bolivari sp. n., P. denticulata sp. n., P. fumosa sp. n., P. nidorosa sp. n., P. sharkeyi sp. n., and Paraleia sp. are illustrated. High-resolution photos of wings for all species are presented. An identification key for world species of Paraleia is provided.