Diversidade de Seirini (Collembola, Arthropleona, Entomobryidae), em áreas úmidas da caatinga

The family Entomobryidae is one of the most diverse families of Collembola in Northeast Brazil. Data on its diversity may be considered undervalued due to low collection efforts in the region. In this study, five areas in the Northeast region were sampled, to evaluate the species richness of this family. The study was done in the Serra da Jibóia, Santa Terezinha municipality, Bahia; Serra das Confusões, Caracol municipality, Piauí; Chapada do Araripe, Crato municipality, Ceará; Mata do Pau-Ferro, Areia municipality, Paraíba and Parque Nacional de Ubajara, Ubajara municipality, Ceará, all considered humid areas of Caatinga. Collections were made using pitfall traps and entomological aspirators. All the collected material was screened, mounted on slides, identified and, finally, the descriptions of some of the new species encountered were made. A total of 48 Entomobryidae species belonging to nine genera were recorded and 27 of these were new to science, representing a percentage of 56.25% of the total. A new record for Brazil was identified and several new records were made to the States. Seira was the genus with wider distribution and it was the only one found in all areas and the most representative with the highest number of recorded species (26). This result was expected, because individuals of the genus Seira have a good adaptability to semi-arid environments, a fact that has already been proven in previous research. Seven new species of Seira were described. A dichotomous key to genera and species of Seirini from Brazil was drafted. This work demonstrates the great potential of Entomobryidae and Seirini in the Northeast, despite having been held in very restricted areas, obtained important results for the knowledge of fauna of the group

Mapeamento cromossômico de genes ribossomais em espécies estuarinas da família Gerreidae Identificação de uniformidade cariotípica e sua empregabilidade com fins biotecnológicos - REPROGEN

Perciformes are dominant in the marine environment, characterized as the largest and most diverse fish group. Some families, as Gerreidae, popularly known as silver jennies, carapebas, or mojarras have a high economic potential to marine fish farming, natural explotation and game fishing. Genetic information of these species are of fundamental importance for their management and production. Despite exist over 13,000 marine fish species described, only 2% were cytogenetically analyzed and less than 1% have some reproductive characteristics known. Induced breeding, cytogenetic characterization and cryopreservation of gametes, represent important areas in applied fish studies. In this project cytogenetic analyzes were performed to acess genetic aspects of Gerreidae species, distributed in coastal and estuarine regions of Northeast Brazil. Different methods for identifying chromosomal regions were employed using conventional techniques (Ag-NORs, C-banding), staining with base-specific fluorochromes (DAPI-CMA3), and physical mapping of ribosomal genes 18S and 5S rDNA, through hybridization in situ with fluorescent probes (FISH). The six species analyzed showed remarkable chromosome conservatism. The 18S and 5S ribosomal genes when analyzed in phylogenetic perspective demonstrate varied evolutionary dynamics, suggesting ocurrence of stasis process in some groups and greater dynamism in others. Double FISH with 18S and 5S probes showed both how efficient cytotaxonomic markers in the homogeneous karyotypes of this group of species. The karyotypic pattern identified in addition to the evolutionary aspects of karyotype, are suggestive of existence of low potential of post-zygotic barrier, prompting further research to prospect for artificial interspecific hybridization of these species of commercial importance

Padrões cariotípicos em tetraodontiformes (Osteichthypes) :redução genômica e mecanismos de diversificação

The Tetraodontiformes order is composed for about 400 species of fish, distributed in ten families, with circuntropical distribution. The morphologic diversity of each family reflects in, part, the different levels of specialization. This group represents an ancestry after-Perciformes and constitutes the last branch of the diffusion of the Teleósteos, occupying a position of prominence. The phylogenetics relationships of the Tetraodontiformes exist diverse works examining and, in all, these families are recognized as groups brothers, being Diodontidae next to Tetraodontidae and Balistidae next to Monacanthidae. Although it possesss a representative number of species, the works involving of the families Balistidae and Monacanthidae are few exemplary, especially species of oceanic islands. In this work cytogenetic studies in five species had been analyzed Cantherhines macrocerus, Cantherhines pullus (Monacanthidae), Melichthys niger (Balistidae), Sphoeroides testudíneus (Tetraodontidae) and Chilomycterus antennatus (Diodontidae); through conventional coloration, Ag-NORs and C banding. Ahead of the different karyological trends of evolution presented by the Tetraodontiformes, the present work also searched to verify the relation existence enters the total size of the chromosomes with the amount of DNA in these groups of Tetraodontiformes. For such, they had been correlated the total size of the chromosomes of these species, with values of content of available DNA in literature. The cytogenetics analyses for the species C.macrocerusJ C.pullus (Monacanthidae) and M.niger (Balistidae), had disclosed 40 chromosomes, all acrocentrics. All possess only one pair of NORs and pericentromeric heterochromatin. For S.testudíneus the found dyploid number was equal 2n=46, with NF=78 (16m+18sm+8st+4a), while that for C.antennatus it possesss 2n=50, with NF=76 (4m+22st+24a). Both species possess simple NORs and pericentromeric heterochromatin blocks. In M.niger, the presence of positive marking (heterochromatin and NOR) in the secondary constriction in the second chromosomic pair suggesting the occurrence of a rearrangement, possibly a fusing involving these homologous ones, indicating that these events had been important for the establishment of the karyological history of this group. A maintenance of the chromosomic constancy found in the populations of C.macrocerus (Monacanthidae) and S.testudineus (Tetraodontidae) perhaps if must for the aiding of the gene flow through oceanic chains. These data contrast with the differentiated kinds of chromosomes of C.antennatus between the Northeast coast and Southeastern, suggesting that the ecological standards of each species, added to the conditions of the marine environment, can be responsible for the karyological delineation of each species. The found characteristics for the species C.macrocerus, C.pullus, M.niger, S.testudineus and C.antennatus add it the available data for other species of Tetraodontiformes. From the data gotten in the present study, it can be inferred that the DNA content possesss direct relation with the total length of the chromosomes

Variação temporal e descrição de novas espécies de collembola (arthropoda, hexapoda) em uma área de caatinga do nordeste do Brasil

Collembola is one of the most abundant and diverse group of terrestrial arthropods, being at the base of the food chain operating in the decomposition process. They have a wide distribution in the world and can be found in practically all habitats. The knowledge of this distinctive fauna is still deficient in brazilian territory, especially in semi-arid region. The aim of this study was to investigate which climatic variables may act as predictors of species richness, abundance of individuals and compositional structure of the taxocenose of Collembola over 12 months in an area dominated by semi-arid Caatinga vegetation, northeastern Brazil and describe new species of the genus Seira found, more diverse taxon of Collembola in Brazil. Samples were collected in João Câmara, Rio Grande do Norte. Ten plots of 20 x 20 meters were established and the specimens were collected with collection effort of one hour/people using entomological aspirator. The identification and description of the species was carried out by studying the morphology and chaetotaxy. Was performed a multiple regression analysis between species richness and abundance of individuals with climatic variables. A total of 1231 individuals belonging to 15 species, 12 genera and nine families. The greatest richness and abundance of Collembola were found during the rainy season. The genus Seira was the most abundant. Rainfall explained the temporal variation in species richness and abundance of Collembola in the semi-arid region, which is consistent with the biology of these animals. The populations of Collembola showed grouped distribution. Three new species of Seira were described and illustrated and all show similarities with species already registered in the national territory

Variação temporal e descrição de novas espécies de collembola (arthropoda, hexapoda) em uma área de caatinga do nordeste do Brasil

Collembola is one of the most abundant and diverse group of terrestrial arthropods, being at the base of the food chain operating in the decomposition process. They have a wide distribution in the world and can be found in practically all habitats. The knowledge of this distinctive fauna is still deficient in brazilian territory, especially in semi-arid region. The aim of this study was to investigate which climatic variables may act as predictors of species richness, abundance of individuals and compositional structure of the taxocenose of Collembola over 12 months in an area dominated by semi-arid Caatinga vegetation, northeastern Brazil and describe new species of the genus Seira found, more diverse taxon of Collembola in Brazil. Samples were collected in João Câmara, Rio Grande do Norte. Ten plots of 20 x 20 meters were established and the specimens were collected with collection effort of one hour/people using entomological aspirator. The identification and description of the species was carried out by studying the morphology and chaetotaxy. Was performed a multiple regression analysis between species richness and abundance of individuals with climatic variables. A total of 1231 individuals belonging to 15 species, 12 genera and nine families. The greatest richness and abundance of Collembola were found during the rainy season. The genus Seira was the most abundant. Rainfall explained the temporal variation in species richness and abundance of Collembola in the semi-arid region, which is consistent with the biology of these animals. The populations of Collembola showed grouped distribution. Three new species of Seira were described and illustrated and all show similarities with species already registered in the national territory

Uma leitura geográfica da reforma agrária potiguar

It understands a study made concerning the main aspects of the Agrarian Reform and the Agricultural Nestings of the Rio Grande do Norte. For in such a way an inquiry became necessary initially on the origin of the Brazilian agrarian concentration passing for the donation of Sesmarias, Land Law, Statute of Land and Ith National Plan of the Agrarian Reformation, as well as of the Social Movements of fight for the land appeared since century XIX: Canudos, Contestado, Cangaço, Ligas Camponesas and MST. Drawing the fight for the land in the Rio Grande do Norte, we rescue the component elements of the first indications of the Agrarian Reform and formation of Agricultural Nestings in the State. In the attempt to unmask the current situation of the Settlements, we investigate some concerning aspects to the conditions of life of the seated ones, that it is marked by innumerable problems that go since the lack of water until the a precariousness of the infrastructure and presence of services, over all with relation to the education and health. For in such a way we work initially on the basis of diverse bibliographical readings, together data-collecting the official agencies and some directly involved entities with the Agrarian Reform in the RN. We utilized also the research of field in 27 Settlements of different Microregions of the State that consisted of the application of interviews together to the leaderships of these Settlements and application of forms with the seated families who resulted in a bigger knowledge concerning the reality of these areas that integrate the Politics of the Agrarian Reform