Repositório RCAAP

The radula of five species of South American Ampullariidae was analysed by Scanning Electron Microscope (SEM) with the purpose of enlarging new studies on the systematic of this family. The studied species were Pomacea -canaliculata (Lamarck, 1822), Pomacea scalaris (d'Orbigny, 1835), Pomella (P.) megastoma (Gray, 1847), Asolene (A.) platae (Maton, 1809) and Felipponea neritiniformis (Dall, 1919). The central tooth shows different attributes which provide the means for generic determination; the analysis of the central tooth, the lateral and marginal ones by SEM adds further information for species differentiation.

The objective of this study was to analyze the gonadossomatic relation of males and females of Brycon opalinus (the Pirapitinga do Sul) in the Serra do Mar State Park-Núcleo Santa Virgínia. The study area included three rivers: Paraibuna, Ipiranga, and Grande. From the gonadossomatic relation, it was possible to determine the reproductive season and strategy of this species. The gonadossomatic relation was high throughout the year for both males and females. Sperm competition and dilution of the ejaculate in the spawning locations favored substantial development of the testicles. The sex ratio of Brycon opalinus was always in favor of females. The existence of sexual dimorphism in this species was confirmed from the larger size of the females.

In the present study, we investigated types of pancreatic endocrine cells and its respective peptides in the Brazilian sparrow species using immunocytochemistry. The use of polyclonal specific antisera for somatostatin, glucagon, avian pancreatic polypeptide (APP), YY polypeptide (PYY) and insulin, revealed a diversified distribution in the pancreas. All these types of immunoreactive cells were observed in the pancreas with different amounts. Insulin- Immunoreactive cells to (B cells) were most numerous, preferably occupying the central place in the pancreatic islets. Somatostatin, PPA, PYY and glucagon immunoreactive cells occurred in a lower frequency in the periphery of pancreatic islets.

We describe the diet of Oligosarcus hepsetus, in the Santa Virgínia Unit of the Serra do Mar State Park. The Paraibuna and Grande rivers in the basin of the Paraíba do Sul River were sampled monthly from January to December 2004. The Alimentary Preference Degree and the frequency of occurrence indices were used to analyze the food items. The diets of Oligosarcus hepsetus in the two localities sampled were very similar, and reinforced the importance of the streamside forests in establishing and maintaining biotic and abiotic conditions in these environments. The species had a carnivorous diet that differed with ontogeny: smaller individuals were principally insectivorous and larger ones ichthyophagous.

The aim of the present work conducted at the Refugio de Vida Silvestre Bahía Samborombón is to analyse the most relevant aspects of the fecundity of Chasmagnathus granulatus and Uca uruguayensis. Samplings were carried out from March 2001 to February 2003. Ovigerous females of U. uruguayensis (N = 13) and C. granulatus (N = 25) were found during spring and summer, their sizes (CW) varied from 9.1 to 11.7 µm for the former species and from 22.8 to 32.4 mm for the latter. The egg diameter in U. uruguayensis ranged from 245 to 260 µm for embryos in the early stage of development and from 250 to 345 µm for those in mid-developmental stage, while in C. granulatus from 250t o 345 µm and from 260 to 365 µm respectively. Fecundity varied from 1126 to 6745 eggs/brood in U. uruguayensis and 15688-57418 eggs/brood in C. granulatus. For those females with broods in mid-developmental stage, several relationships were made. For U. uruguayensis the best correlation coefficients were obtained for the relationships: female weight vs. egg mass weight and carapace width vs. egg mass weight; for C. granulatus the best association was obtained between female size and the egg number and the egg mass weight.

Mangrove oysters Crassostrea rhizophorae were sampled monthly in the estuary of Jaguaribe River, on the east coast of Ceará State, Brazil, between August, 2000 and December, 2001, making up 170 individuals. The water temperature varied from 26 to 30 °C and salinity from 21 to 42‰. The animals' size ranged from 3.4 to 7.2 cm height. Macroscopical and histopathological analyses were carried out in the oysters' tissues. The histological exams showed protozoans and metazoans of genera Nematopsis and Tylocephalum, respectively. Nematopsis prevalence varied from 60 to 100% and it was higher in the gills and mantle. The oocysts presented a mean size of 11.5 µm (±1.32) length and 9.1 µm (±1.06) width (n = 30), up to 3 oocysts/phagocyte having been observed. Several animals presented focal hemocitical reaction. The percentage of Tylocephalum was 1.7%. In spite of the high infection prevalence by Nematopsis, infected animals did not have their reproductive cycle impaired.

This study aimed to evaluate the infection rates of snakes by pentastomids in the semi-arid region of Brazil. Fifteen snakes (four Micrurus ibiboboca (Merrem, 1820) and eleven Philodryas nattereri Steindachner, 1870) were collected between January and April of 2005, in the municipality of Crato (07° 14' S and 39° 24' W), State of Ceará, Brazil. Laboratorial analysis of the respiratory tracts of the sampled snakes indicated differences in host infection rates: four individuals of P. nattereri (36.4%) were infected by Cephalobaena tetrapoda Heymons, 1922 (mean infection intensity 1.5 ± 0.28, 1-2) and three specimens (27.3%) by Raillietiella furcocerca (Diesing, 1863) (2.3 ± 1.32, 1-5). Only one individual of M. ibiboboca (25%) was infected by a non-identified species of Raillietiella sp. These are the first data on pentastomid infection in snakes in Northeastern Brazil and both snake species comprise new host records for the pentastomids. The results also indicate that the generalist parasites C. tetrapoda and R. furcocerca share their definitive hosts.

The paper presents the description of Seminavis atlantica Garcia, a psammic marine diatom from dissipative sandy beaches from southern Brazil. It is characterized by its convex linear dorsal margin (37 to 50% of its length is in a straight line), linear ventral margin and raphe located very close to the ventral margin. Its morphology is compared to similar species such as Amphora clevei Grunow, Amphora angusta (Greg.) Cleve var. orientalis Allem, Amphora ventricosa Gregory and Amphora eulesteinii Grunow.

The purpose of this study was to explore the role of L-5-hydroxytryptophan (L-HTP) and its relationship with the renin-angiotensin system (RAS) on the drinking behavior in Japanese quails. Normally-hydrated quails that received injections of L-HTP (12.5; 25 and 50 mg.kg-1) by the intracoelomic route (ic) expressed an increase in water intake, which was inhibited by captopril, an angiotensin converting enzyme (ACE) inhibitor. In addition, captopril also induced such a response in birds under previous fluid deprivation. High doses of captopril (35-70 mg.kg-1, sc) in normally-hydrated quails decreased the spontaneous water intake while low doses of captopril (2-5 mg.kg-1, sc) did not prompt water intake after L-HTP administration. Losartan, an AT1 receptor antagonist in mammals, did not change the water intake levels in normally-hydrated or water-deprivated birds. Serotonin (5-HT) injections did not provoke its known dipsogenic response.

The Pampas deer (Ozotoceros bezoarticus) is one of the most endangered Neotropical cervid with populations that have been drastically reduced to small and isolated ones, mainly because of its habitat destruction. Random amplified polymorphic DNA (RAPD) markers were used to analyze population divergence and genetic variation within and between two populations corresponding to distinct subspecies. The RAPD markers displayed substantial genetic variation with all animals possessing unique RAPD phenotypes over 105 polymorphic bands produced by 15 primers. An analysis of molecular variance (AMOVA) and a neighbor-joining cluster analysis were performed to assess levels of differentiation between populations. No differentiation was recorded and about 96.0% (P < 0.00001) of the total variance was attributable to variation within populations. This result is quite distinct from data obtained by the analysis of the mtDNA control region, and is discussed on the basis of genetic differences between the different markers and the male-biased dispersal patterns generally observed in the mammal species. The data presented herein are potentially useful for future taxonomic and genetic studies in this species, for the monitoring of the genetic variation observed within these populations, and for the development of management guidelines for its conservation.

The Neotropical otter is one of the least known otter species, and it is considered to be threatened to various degrees throughout its geographic range. Little information exists on the ecological characteristics of this species, and no genetic study has been published about it until now, hampering the design of adequate conservation strategies for its populations. To contribute with genetic information to comprehensive conservation efforts on behalf of L. longicaudis, we characterized the molecular diversity of the 5’ portion of the mtDNA control region in samples from this species collected in Southern and Southeastern Brazil. The sequence analysis revealed a high level of haplotype diversity (h = 0.819; SE = 0.0052) and nucleotide variability ranging from 0.0039 to 0.0067. One of the sampled haplotypes was the most common in both regions and, from this sequence, several other (locally occurring) haplotypes could be derived by single point mutations. No significant genetic differentiation was observed between the Southern and Southeastern regions.

The giant otter (Pteronura brasiliensis) is an aquatic mammal of the Mustelidae family, endemic to South America. Its original distribution corresponds to the region from the Guyanas to Central-North Argentina, but it is extinct or on the verge of extinction in most of its historical range. Currently, the species is considered endangered by the World Conservation Union (IUCN). Based on its geographic distribution in the South American continent and on some morphological characters, two subspecies were suggested: P. brasiliensis brasiliensis, occurring in the Amazon and Orinoco River Basins, and P. brasiliensis paranensis, in the Paraná and Paraguai River Basins. However, there is no consensus on assuming this subspecies division and no detailed studies have been carried out to elucidate this question. This study aims to evaluate the genetic diversity and population structure of Pteronura brasiliensis along its range in Brazil to check the possibility of the existence of two distinct subspecies using also a reciprocal monophyly criterion. We analyzed the control region, and the Cytochrome b and Cytochrome c Oxidase subunit I genes of the mitochondrial DNA in several giant otter populations from the Amazon and Paraguai River Basins. Analyses have indicated some degree of geographic correlation and a high level of inter-population divergence, although the subspecies division is not highly supported. As we observed strong population structure, we cannot rule out the existence of further divisions shaping the species distribution. The results suggest that a more complex population structure occurs in P. brasiliensis, and the conservation practice should concentrate on preserving all remaining local populations.

In this study we propose the analysis of genetic diversity of the common three-toed sloth, Bradypus variegatus, in an attempt to understand population structure, identify divergent intraspecific units, and contribute to the knowledge of biodiversity in the neotropical forests. We analyzed a 387 bp segment of the mitochondrial DNA control region in 28 individuals distributed in different localities of both Atlantic and Amazon forests. Our results demonstrated that the genetic diversity of B. variegatus is distributed in six management units, MUs. The observed MUs encompass six phylogenetic lineages and represent respectively north and south regions of Atlantic forest, three regions within the Amazon forest, and a transition region between these two biomes. Considering the fact that these MUs are concordant with phylogroups and endemism areas already described for other vertebrate species, we can say that the study of B. variegatus, a widely distributed and not endangered species, can help to identify areas for conservation biology purposes in neotropical rain forests.

The goal of conservation biology should be related to the preservation of species and also to the evolutionary and ecological processes that were responsible to form them and that are still acting. We review the conservation status of the species of tuco-tuco (Ctenomys torquatus, C. lami, C. minutus, and C. flamarioni) from southern Brazil, and relate these data to the geological history of a particular area in that region, the Coastal Plain of the States of Rio Grande do Sul and Santa Catarina. The implications of the data on these species from the Southeastern Brazil are also discussed in relation to the evolution and risk of extinction of these subterranean rodents.

The present study determined nuclear and mitochondrial (mtDNA) levels of genetic variability and phylogeographic patterns in breeding populations of Roseate Spoonbill (N = 57), Wood Stork (N = 89), and Jabiru Stork (N = 30), sampled in the Brazilian Pantanal. These species were selected since they are bioindicators of wetlands’ health and are threatened in other parts of their distribution. As they are in close association with this ecosystem, they are appropriate for studying the effects of Pleistocene climatic changes on their demographic patterns. Levels of nuclear genetic diversity in Pantanal populations were not significantly different from those of other populations throughout the American continent, where they are considered threatened or of special concern. Reduced levels of mtDNA genetic diversity were observed in the Central American population of Jabiru Stork in comparison to the Pantanal population. Recent demographic expansion in the Pantanal was markedly evidenced by unimodal patterns of mismatch distribution and Fu’s Fs neutrality test in these three species. We hypothesize that the average time of population expansion (between 30,843 and 14,233 years before present) is associated to responses of these birds’ populations to paleoclimatic changes in these wetlands during the last glaciation period. We recommend special conservation efforts with the Jabiru Stork populations, a genetic monitoring program based on mtDNA, and an ecological characterization of these waterbirds species throughout their distribution range.

Forest fragmentation affects bird populations in many ways, modifying the composition of communities and favouring open country species. The Atlantic Forest is considered one of the most important biomes in the world, due to its great biodiversity, accelerated rates of deforestation, and high endemism. Despite these characteristics, few studies have evaluated the effects of forest fragmentation in the genetic structure of Atlantic forest bird populations. So, this study aims to verify the effects of forest fragmentation in the genetic population structure of Conopophaga lineata, through RAPD markers. To achieve this goal, 89 C. lineata individuals were captured in nine Atlantic Forest fragments in Minas Gerais State. The RAPD data indicate that forest fragmentation has not affected the genetic variation of C. lineata populations (Mann-Whitney U = 3.50; p = 0.11). Great part of the genetic variability of this species is found within populations and it was not observed a correlation between genetic and geographic distance (Mantel test t = 0.6250; p = 073). UPGMA analyses did not show defined clades and all branches showed low statistical support. The low population differentiation observed in this species can be due to a high gene flow among populations or a recent fragmentation. Thus, the current diversity status of C. lineata populations indicates that this species is not significantly affected by fragmentation. However, more genetic studies are essential to improve conservation strategies of Brazilian Atlantic Forest birds.

Randomly amplified polymorphic DNA (RAPD) markers were used to analyze genetic differentiation among three populations of the endemic Black-cheeked Gnateater (Conopophaga melanops melanops) within a larger pristine reminiscent of the Brazilian Atlantic Forest. Analyses of molecular variance (AMOVA) (phiST = 0.13149, P < 0.0001) and the nonparametric test for homogeneity of the molecular variance (HOMOVA) (B = 0.32337; P = 0.0019) showed a statistically significant genetic divergence among the three Black-cheeked Gnateater populations in a continuous transect of 250 km. Some hypothetic explanations for these results are the sedentary nature of the species and the historical isolation of the populations in refuges during the Pleistocene. The present results suggest that the local populations were naturally differentiated along the entire original range before the recent process of massive deforestation.

The Thamnophilus punctatus complex has been recently reviewed on the basis of morphological and vocal characters, and is divided in six different species. Two of the new species, although well defined on the basis of morphological differences, could not be unambiguously distinguished through their loudsongs. The Planalto Slaty-antshrike (Thamnophilus pelzelni) and the Sooretama Slaty-antshrike (T. ambiguus) are most easily distinguished by subtle and localized changes in plumage colors of males and females. In the present study we used sequences of the control region, Cytochrome b, and ND2 genes, of the mitochondrial DNA (mtDNA) to evaluate the levels of molecular differentiation between these two species. The mean pairwise distance between the two species was 3.8%, while it varied from 2.7% to 4.9% for each mtDNA region. Although extensive variation was also detected among haplotypes within species, especially for T. ambiguus, we suggest that the genetic divergence found between T. ambiguus and T. pelzelni is high enough to corroborate the separate species status of these two antbird taxa.

Parrots of the genus Amazona are among the most threatened species of the Order Pscittaciformes. This work describes allozyme polymorphisms in three Amazon parrot species - the Blue-fronted Amazon (Amazona aestiva), the Orange-winged Amazon (Amazona amazonica), and the Festive Amazon (Amazona festiva) -, and provides useful data for the evaluation of their genetic variability. We electrophoretically analyzed blood samples from 68 wild-caught individuals, maintained in captivity in three Brazilian zoos. Eight of the ten studied enzyme loci exhibited polymorphism. Glucosephosphate isomerase (Gpi) proved to be a diagnostic locus for the identification of these Amazon species. The expected average heterozygosity of the Blue-fronted Amazon (0.060) differed significantly from the expected heterozygosities of the Orange-winged Amazon and the Festive Amazon (0.040 and 0.039, respectively). This result was discussed as a consequence of hybridization between two geographic A. aestiva subspecies, and alternatively as a particular trait of this species. Genetic variability of the Blue-fronted Amazon compared to birds in general is not low on a species-wide level, despite the fact that this parrot is one of the most illegally traded species. Allozyme analysis proved to be an useful tool in monitoring the genetic variation within the genus Amazona and can be applied in the management program of other threatened species of this genus.

Brycon hilarii is a migratory fish widely distributed throughout the Paraguay River Basin. It is appreciated in sport fishing and for its superior meat quality. It is also the main species for tourist attraction in the Bonito region (State of Mato Grosso do Sul, Brazil). Considering the lack of information on the genetic structure of the fish of this species, the aim of the present study was to detect the genetic variability of Brycon hilarii through RAPD markers. A total of eighty specimens collected in different seasons at four sites of the Miranda River sub-basin (Paraguay River Basin, Brazil) were used for analysis. The results of genetic similarity, Shannon diversity, and AMOVA revealed differences between the sampling sites. Through AMOVA, differences between populations were more evident among the animals collected during the non-reproductive season, corresponding to a time of less movement of these fish. A population structuring model in which B. hilarii appears organized into genetically differentiated reproductive units that coexist and co-migrate through the studied system was suggested, contrasting the currently accepted idea that freshwater migratory fish form large panmictic populations in a determined hydrographic system. Despite the lack of a complete picture regarding the distribution of B. hilarii in the studied region, this initial idea on its population genetic structure could be an important contribution to providing aid for management and conservation programs of these fish.