Catapyrenium (Verrucariaceae) species from South America

13 species of the lichen genusCatapyrenium are reported from South America. Five species (C. analogicum, C. andicolum, C. exaratum, C. lachneoides, andC. podolepis) are described as new. A key to the species known from South America is presented. Remarks on taxonomy, ecology and distribution of the species are given.Studies on the lichen genusCatapyrenium (Verrucariaceae) III. For second part seeBreuss (1991).     

High‐latitude Hirnantian (latest Ordovician) brachiopods from the Eusebio Ayala Formation of Paraguay,Paraná Basin

Abstract: Examination of newly collected brachiopods from the Eusebio Ayala Formation of Paraguay reveals the occurrence of Arenorthis paranaensis sp. nov., Plectothyrella? itacurubiensis sp. nov., Hindella sp. and Eostropheodonta conradii (Harrington). Associated graptolites of the N. persculptus Zone indicate that the age of the fossiliferous beds is Hirnantian. The overall generic composition of the fauna is similar to that of the atypical Hirnantia Fauna of the Bani Province. The record in Paraguay of Arenorthis, hitherto only known from North Africa, together with species of Plectothyrella? and Eostropheodonta different from those recorded in the Kosov Province, emphasizing the affinities between the Paraguayan fauna and the low‐diversity African assemblages. Stratigraphic and faunal evidence indicates that biogeographical links between South America and Africa already existed by the end of the Ordovician when most of the intra‐cratonic basins of Gondwana were flooded during the postglacial sea level rise.     

A new species of Ruellia (Acanthaceae) from Paraguay

A new species,Ruellia woolstonii C. Ezcurra from eastern Paraguay, is described, illustrated, and compared to related species.

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Resumen  Una nueva especie,Ruellia woolstonii C. Ezcurra de Paraguay oriental, se describe, ilustra, y compara con especies relacionadas.

     

Distribution, abundance, and conservation of Vinaceous Amazons (Amazona vinacea) in Argentina and Paraguay

ABSTRACT.   Vinaceous Amazons ( Amazona vinacea ) are endemic to the Atlantic forest of southeastern Brazil, eastern Paraguay, and the province of Misiones in Argentina. We searched for Vinaceous Amazons throughout the western part of its range in Argentina and Paraguay during 1639 days of fieldwork from 1997 to 2006. These parrots have disappeared from most areas where they were historically recorded in these countries, and are now limited to a few sites in northeastern Paraguay and central Misiones (Argentina). We estimate the minimum remaining populations at 220 individuals in Paraguay and 203 individuals in Argentina. Important sites for the species are (1) the farming area from San Pedro to Tobuna (Misiones, Argentina) and (2) the Itaipú reserves complex and Reserva Natural Privada Itabó (Paraguay). In our surveys, Vinaceous Amazons were absent from the largest tracts of forest in Misiones, and were most often observed feeding, roosting, and nesting in small forest remnants and in agricultural areas that included forest fragments and isolated trees. Threats to amazons in these areas include nest poaching, forest clearing, and being shot as a crop pest. We confirmed 40 Vinaceous Amazons kept as pets in 35 homes between San Pedro and Tobuna. Environmental education and law enforcement are urgently needed to reduce threats in populated areas, and subsistence farmers need technical and logistical support to slow or stop the conversion of forest into cropland. Finally, additional study is needed to determine this amazon's habitat preferences, nest site requirements, and demography in different habitats.     

Ecological zoogeography of the bats of Paraguay

Aim To relate the composition of bat assemblages in Paraguay to environmental factors (vegetation) and to test the hypothesis that the observed patterns of distribution of Paraguayan mammals is ultimately due to soils and geological features. Location Paraguay. Methods Museum specimens were used to create a data base of 3762 individuals of forty-eight species collected in twenty-six 50 × 50 km sites distributed throughout the country. Proportion of each of sixteen vegetation types per site was estimated from vegetation maps. Vegetation and bat data were related using canonical correspondence analysis (CCA) and Mantel tests. The same analyses were performed with the bat data grouped in terms of trophic strategies. Results A significant relationship was found between composition of vegetation and composition of bat assemblages. CCA ordination arranged plant associations and bat assemblages into three distinct groups: Dry Chaco, Floodable Lands and Eastern Paraguay, which correspond to the major characteristics of the Paraguayan vegetation, geology and soils. Frugivorous bats were restricted to Eastern Paraguay and Floodable Lands, whereas most insectivore and omnivore species occur across the entire country. However, the maximum abundance of insectivorous and omnivorous species within each genus indicates that there is at least a partial segregation of species to one of the three regions, and in those cases where the maximum abundance of congeneric species coincide, those species differ considerably in size. Main conclusions The Paraguayan bat fauna is a composite of species from various South American biomes, with no endemic species. However, species are not randomly distributed across the country despite the lack of geographical barriers and the high dispersal capabilities of bats. Instead, species presence at any given site is strongly associated with vegetation patterns that are ultimately the result of the geological history of the area. This correlation can be explained partially in terms of habitat suitability and resource availability. Additionally, results suggest that interspecific interactions are also an important component in determining the composition of a given bat assemblage.     

Genetic studies in Paraguay: blood group, red cell, and serum genetic patterns of the Guayaki and Ayore Indians, Mennonite settlers, and seven other Indian tribes of the Paraguayan Chaco

Genetic studies of 540 Paraguayan Indians from nine tribal groups and 51 Mennonites are presented for ABO, MNSs, P₁, Rh, Kell, Lewis, Duffy, Diego; for serum immunoglobulins and haptoglobins, G6PD-deficiency, and thalassemia trait. Group O gene frequencies for all Indian groups were 1.00; for r (cde), 0.00. Tapiete, Lengua, Toba, and Sanapana R_z (CDE) frequencies were among the highest ever reported. N frequencies were high for Ache Kwera (Guayaki), Lengua, Cheroti, Guarayu, Tapiete; N and s low for Ayore. MS frequencies were high for Sanapana, Lengua, Ayore; Ns for Tapiete. Diego was notably absent for Toba, Lengua, Guarayu, Tapiete, Ayore. Homogeneous frequencies for Fy^a (1.000) occurred among Guarayu and Tapiete, and for P₁ among Guayaki. Inv(a) frequencies were low for Cheroti, Chulupi, Guayaki. Hp 1 among Guayaki (Ache Kwera 0.15) is lowest ever reported. G6PD deficiency and abnormal hemoglobins were uniformly absent from all groups. Mennonite results were homogeneous and point toward Dutch origins. Differences among groups studied, and between Paraguayan and other Amerinds emphasize importance of genetic drift and founder principle. Abandonment of their tribes by mixed-blood offspring is partly responsible for apparent genetic purity and homogeneity of groups.     

Giant chacoan peccary: Feeding and social behavior of a captive group in natural habitat

Social behavior of the giant Chacoan peccary, also known as the taguá, is relatively unknown due to the harsh environment and endangered status of the population. In order to characterize feeding and social behaviors, a group of 7 adults, 2 juveniles, and 3 infants was observed in their feeding area for 99.25 hours over 18 days during October and November 1989. All animals were housed in a 2 ha natural-habitat enclosure in the Chaco of Paraguay. It was determined that these peccaries fed in intervals throughout daylight hours and that juveniles spent more time per approach in the feeding area than adult males. It was also observed that infants were accepted and well tolerated by the entire group, including adult males. These observations have relevance to taguá behavior in the wild and provide new insights into social patterns of this recently discovered species.     

Generation of superoxide anion and hydrogen peroxide induced by nifurtimox in Trypanosoma cruzi.

Addition of nifurtimox (a nitrofuran derivative) to Trypanosoma cruzi culture (epimastigote) forms induced an increase in the respiratory rate and the release of H₂O₂ from the whole cells to the suspending medium. Growth-inhibiting concentrations of nifurtimox were able to stimulate O_2? production by the T. cruzi mitochondrial fraction supplemented with NADH (or succinate), and also to enhance the generation of O_2? by the microsomal fraction with NADPH as reductant.