Vertical displacement during late-collisional escape tectonics (Brasiliano Orogeny) in the Ribeira Belt, São Paulo State, Brazil

During the Brasiliano-Pan-African Orogeny, West Gondwana formed by collisional processes around the Sao Francisco-Congo Craton. The Ribeira belt, in southeastern Brazil, resulted from northwestward collision (650-600 Ma), followed by large-scale northeast-southwest dextral strike-slip shear movements related to late-collisional escape tectonics (ca 600 Ma).In São Paulo State, three groups, also interpreted as terranes, are recognised in the Ribeira Belt, the Embu, Itapira and Sao Rogue Groups. The Embu and Itapira Groups are formed of sillimanite-gneisses, schists and migmatites intruded by Neoproterozoic calc-alkaline granitoids, all thrusted northwestward. The Sao Rogue Group is composed of metasediments and metavolcanics in greenschist-facies. Its deformation indicates a transpressional regime associated with tectonic escape. Sub-alkaline granites were emplaced in shallow levels during this regime. Microstructural studies along the Itu, Moreiras and Taxaquara Shear Zones demonstrate the coexistence of horizontal and Vertical displacement components during the transpressional regime. The vertical component is regarded as responsible for the lateral juxtaposition of different crustal levels. (C) 1999 Elsevier B.V. Limited. All rights reserved.

Rift to post-rift evolution of a passive continental margin: the Ponta Grossa Arch, SE Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Leishmania chagasi infection in cats with dermatologic lesions from an endemic area of visceral leishmaniosis in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Leishmania chagasi infection in cats with dermatologic lesions from an endemic area of visceral leishmaniosis in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Two new species of Bdellidae (Acari : Prostigmata) from Brazil

Two new species, Bdella ueckermanni n. sp. and Spinibdella denheyeri n. sp. (Acari: Bdellidae), are described from plants in southeastern Brazil.

Breeding of Ornidia obesa (Diptera: Syrphidae: Eristalinae) on Pig Carcasses in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Geographic variation of Africanized honey bees (Apis mellifera L.) in Brazil: Multivariate morphometrics and racial admixture

The correspondence between morphometric and isozymic geographic variation patterns of Africanized honey bees in Brazil was analyzed. Morphometric data consisted of mean vectors of 19 wing traits measured in 42 local populations distributed throughout the country. Isozymic data refer to allelic frequencies of malate dehydrogenase (MDH), and were obtained from Lobo and Krieger. The two data sets were analyzed through canonical trend surface, principal components and spatial autocorrelation analyses, and showed north-south dines, demonstrating that Africanized honey bees in southern and southeastern Brazil are more similar to European honey bees than those found in northern and northeastern regions. Also, the morphometric variation is within the limits established by the racial admixture model, considering the expected values of Africanized honey bee fore wing length (WL) in southern and northeastern regions of Brazil, estimated by combining average values of WL in the three main subspecies involved in the Africanization process (Apis mellifera scutellata, A. m. ligustica and A. m. mellifera) with racial admixture coefficients.

New species of Hylodes from the Atlantic forest of Brazil (Amphibia: Leptodactylidae)

A new species of leptodactylid frog is described from Eldorado, state of Sao Paulo, southeastern Brazil. The new species is a member of the Hylodes lateristrigatus group and is characterized by its large size, slightly rugose to rugose dorsal skin texture, robust body, and high number of notes per call. Descriptions of the advertisement call and information on natural history are provided.

Ecology and conservation of the jacutinga Pipile jacutinga in the Atlantic Forest of Brazil

The jacutinga Pipile jacutinga was formerly one of the most abundant game bird cracids in the Atlantic forest of Brazil. Nowadays this species is vulnerable to extinction due to hunting and habitat loss. The ecology of the jacutinga was studied at Parque Estadual Intervales, Sao Paulo, Brazil from October 1993 to December 1995 and in adjacent areas. Jacutingas were observed to feed mainly on the sugar-rich fruit of 41 species. We recorded a low index of abundance for the jacutinga (0.018) or c.1.7 birds/km2 at Intervales, one of the best protected areas within their range. Surveys carried out in the Atlantic forest of Sao Paulo found jacutinga populations in 14 localities. Probably < 1500 birds survive in the best protected areas. The species' stronghold in southeastern Brazil is in the mountains of Serra de Paranapiacaba, an area protected by several parks suffering from hunting and palm heart harvesting and threatened by a hydroelectric project.

Key to the soldiers of Atlantitermes Fontes 1979, with a new species from Brazil (Isoptera Termitidae Nasutitermitinae)

A soldier-based key for the identification of the species of the neotropical termite genus Atlantitermes Fontes 1979 is presented. The diagnostic characters for the genus are reviewed and discussed, and the upturned nasus is excluded bacause it is not present in the soldier of every species. A. stercophilus n. sp., from the cerrado vegetation of Minas Gerais, Brazil, is described and illustrated. A. osborni (Emerson 1925) is recorded for the first time in the cerrado vegetation of southeastern Brazil. Drawings of the soldier of A. kirbyi (Snyder 1926) are presented for the first time.

The Bauru Group: A continental Cretaceous unit in Brazil - Concepts based on micropaleontological, oxygen isotope and stratigraphical data

The integration of outcrop and subsurface information, including micropaleontological data, facies and sequence stratigraphic studies, and oxygen isotope analysis, allow us to present a new stratigraphic model for the Cretaceous continental deposits of the Bauru Group, Brazil. Thirty-eight fossil taxa were recovered from these deposits, including 29 species of ostracodes and 9 species of charophytes. Seven of these ostracode species and three subspecies are new and formally described here. The associations of Chara barbosai - Ilyocypris cf. riograndensis, found in the Adamantina Formation, and Amblyochara sp. - Neuquenocypris minor mineira nov. subsp., found in the Marília Formation. Ponte Alta Member, represent two distinct groups that are respectively Turonian-Santonian and Maastrichtian (probably Late Maastrichtian) in age. Therefore, a hiatus, encompassing more than 11 Ma, separates those two formations. From bottom to top, four depositional cycles were recognized in the Bauru Group in western São Paulo: cycles 1 and 2 belong to Caiuá Formation (fluvio-lacustrine and lacustrine deposits in the Presidente Prudente region), cycle 3 to the Santo Anastácio and lower Adamantina Formation (respectively fluvial and lacustrine deposits), and cycle 4 to the upper Adamantina Formation (fluvio-lacustrine facies). An erosional unconformity separates the Caiuá and Santo Anastácio Formations (between cycles 2 and 3). The Marília Formation is a distinct unit from the underlying succession; it does not occur in western São Paulo, but is found in restricted areas of São Paulo, Minas Gerais, Mato Grosso do Sul and Goiás States. During the deposition of the Bauru Group (Aptian? to Maastrichtian) the climate was hot and arid-semiarid. Shallow lakes underwent fluctuations in expansion (wet phases) and contraction (dry phases), as well as variations in salinity. During the deposition of the Adamantina Formation (Turonian-Santonian) there were long, dry periods that caused segmentation of large lakes (due to topographic irregularities in the basaltic substrate) and sometimes exposures of the lake floors; when flooded these lake floors were colonized by extensive meadows of single species of charophytes. Small ephemeral ponds, that were hydrochemically unstable and colonized by multiple species of charophytes, were the depositional sites for the marls and mudstones of Ponte Alta Member (Maastrichtian, Late Maastrichtian?). Our micropaleontological age control, combined with the Late Cretaceous ages of volcanic ashes found in the southeastern Brazil coastal basins, and the stratigraphic position of analcimites from the Jaboticabal-SP region, suggest a Late Coniacian-Santonian age for important magmatic events occurred in the interior of Brazil (north-central São Paulo State, Triângulo Mineiro, and southwestern Goiás State).

Influence of artificial reefs on fish assemblage of the Barra Bonita Reservoir (São Paulo, Brazil)

This paper deals with the effects of introduced artificial reefs on the diversity of freshwater fish communities in lentic and lotic zones of a very impacted river in southeastern Brazil. To accomplish this goal, artificial reefs were introduced, in December 1997, in the Barra Bonita reservoir and in the lotic zone immediately below the dam. Fish diversity was always higher in the lotic zone than in the reservoir. Accordingly, fish diversity near the artificial reefs was consistently higher than in the control areas. We propose that the higher environmental complexity in the lotic zone, as compared to the reservoir, is incremented in areas where artificial reefs were introduced; also, we present that, in both areas, diversity is mainly affected by the introduction of artificial reefs.

Holocene paleoclimatic reconstruction based on the Lagoa Dourada deposits, southern Brazil

The Lagoa Dourada is a circular-shaped pond formed on the Furnas Formation (Devonian of the Paraná Basin), filled by late Pleistocene - Holocene sediments. It lies in the hydrographic basin of the Guabiroba River, a tributary of the Tibagi River situated in the Campos Gerais region of the State of Paraná, southern Brazil. The pond is about 200 m in diameter and the maximum water depth is 5.4 m. Geological, chemical, textural and mineralogical studies on a core sample of the sediments collected from the Lagoa Dourada, 12.2 m thick, was obtained for investigations of paleoenvironmental changes as well as to provide additional data to support previous reconstructions based on palynomorphs and diatoms. Within the period recorded in the core, the pond has been filled by sandy material introduced by springs at the northern edge of the pond as well as by muddy material brought in by floodwaters of the Guabiroba River. Thus, the sandy layers could be interpreted as evidence of drier climates with consequent diminution of fluvial overflow, but with maintenance of the sandy deposits coming from springs. The occurrence of euhedral pyrite in the sediments, locally associated with gypsum, may indicate periods of increase in the organic matter content or an increase in the water salinity, what could be related to greater evaporation under drier paleoclimate regimes. Three cycles defined by an increase in the total carbon content of the sediments of the pond were observed. These cycles seem to correspond to an increase in the isotope ratio 13C/12C (δ13C). Several hypotheses can be suggested to explain the presence of these cycles, including the alternation of wetter or drier climatic phases. The convergence of the sedimentological data obtained during this study with previous microfossil paleoclimatic (pollens and diatoms) indicators and radiocarbon dating suggests that a drier paleoclimatic phase occurred around 8720±150 years B.P. The evidence for a second drier phase in more recent times is less consistent. This subsequent phase could correspond to the drier phase in southern and southeastern Brazil between 5000 and 3000 years B.P. as suggested by other paleoclimatic studies.

Alien fishes in lakes of the Doce river basin (Brazil): Range, new occurrences and conservation of native communities

The present study shows the distribution of alien fish species in tropical lakes in the middle Doce river basin, southeastern Brazil, obtained from a rapid assessment program. The causes for their introductions were sport-fishing improvement in some specific lakes and aquaculture in the studied basin. Presently, these species have a wide distribution occurring in 41 of the 54 lakes studied, representing an actual threat to regional native fish community. The natural connection among lakes and streams during the rainy season and the dispersal mediated by local people are the main invasion agents for alien fishes. The success of these invaders is probably due to absence of pre-existing effective competitors or top-predators in the invaded communities. We consider that the eradication of alien fishes by means of the available management tools may be very difficult due to the large number of lakes invaded and to the wide spectrum of lake conditions and resources exploited by these alien species. We recommend the use of environmental education as a tool to stop the human-mediated dispersion of aliens and to improve conservation of native fish community in lakes where these alien species are not present yet. © 2004 Instituto de Ciências Biológicas - UFMG.

Reproductive phenology of Atlantic forest tree species in Brazil: An eleven year study

This paper describes the reproductive phenorhythms of tree species in a tropical seasonal lowland forest in Southeastern Brazil. Every two weeks, five individuals of 41 species were observed for the occurrence of flowering and fruiting, from May 1982 to December 1992. All phenophases showed high seasonality, when considering the whole set of species, but the amplitude of the cycles was much more variable between years; only 13 species had regular flowering. Infra-annual flowering and fruiting were found in 11 and four species, respectively, while only one species flowered and fruited continually. Supra-annual cycles were observed in four (flowering) and seven (fruiting) species. An increase was observed in number of species and individuals flowering and fruiting from 1990 to 1992, following mainly an elevation in the absolute minimum air temperature. These data suggest a relationship between reproductive phenology and major climatic phenomena like El Niño events and solar activity cycles. © International Society for Tropical Ecology.