4 resultados para armored catfishes
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
Cytogenetic studies have been revealing a great diversity not detected, until then, in several families of fishes. Many of these groups, especially those that exhibit great diversity, like Perciformes and Siluriformes, possess species with difficult morphologic characterization, called cryptic species, commonly detected through karyotypic analyses, which reveals outstanding interespecific variations with relationship to the number and its chromosomal structures. Thus, the present work intends to contribute for the cytogenetic knowledge of marine and brackish fish species, because they peculiar life habits and by lack of cytogenetic data of your genetic aspects. Therefore, cytogenetic studies were developed in a species of Apogonidae (Perciformes), two species of sea catfishes of the family Ariidae (Siluriformes) and brackish fish Paurachenipterus galeatus (Siluriformes, Auchenipteridae), through C banding, Ag-NOR, use of base-specific flourochromes (DAPI and CMA3), as well as FISH (Fluorescent in situ hybridization) using ribosomal DNA probes 5S and 18S. The present results contribute to a better understanding of the processes of differentiation patterns and chromosome evolution in these groups. The use of other approaches (the morphology and molecular tools) will allow a larger understanding of the genetic and biological diversity of the Brazilian ichthyofauna.
Resumo:
The research aimed two objectives: 1st) identifying and describing the metaphors of the inflation, in a corpus of 18 texts of economic journalism, from Joelmir Beting, written in the last trimester of 2002, at the moment of the government s transition of president Fernando Henrique Cardoso to Luiz Inácio Lula Da Silva. 2nd) verifying the recognition of the metaphors by the students of the basic education of a private school from Natal. 91 metaphors had been identified, analyzed in the perspective of the conceptual metaphor s theory, by Lakoff and Johnson (2002), on the basis of the distinction between conceptual metaphor and metaphoric expressions, and between domain-source/domain-target. 10 underlying conceptual metaphors had been inferred, being that the domains-source used more frequently to characterize the inflation had been those ones according to the human being and the animals and, of a less imaginable form, to the ways of transport (car, aircraft). These general conceptual metaphors had been unfolded in other s more specific ones ( animal specifying itself in lion , dragon , dog , etc.). Another result was the identification of metaphoric expressions with two or more meanings , with relation to more than one conceptual metaphor or explicit, in the same expression, two domains-source (for example: armored dragon ) and contributes, of a relevant form, for the semantic struturation of the text. The understanding of the metaphors was verified through an activity of domains-source s identification (10 metaphoric statements and fulfilling of the gap in the phrase the inflation is a/an ) applied in a group of 8th year of the basic education (12-13 years old, with 14 girls and 17 boys) from a school of good social and economic positions from Natal-RN. There weren t great difficulties on the part of the students in recognizing the domains-source involved: about 80% to the great majority of the statements
Resumo:
The research aimed two objectives: 1st) identifying and describing the metaphors of the inflation, in a corpus of 18 texts of economic journalism, from Joelmir Beting, written in the last trimester of 2002, at the moment of the government s transition of president Fernando Henrique Cardoso to Luiz Inácio Lula Da Silva. 2nd) verifying the recognition of the metaphors by the students of the basic education of a private school from Natal. 91 metaphors had been identified, analyzed in the perspective of the conceptual metaphor s theory, by Lakoff and Johnson (2002), on the basis of the distinction between conceptual metaphor and metaphoric expressions, and between domain-source/domain-target. 10 underlying conceptual metaphors had been inferred, being that the domains-source used more frequently to characterize the inflation had been those ones according to the human being and the animals and, of a less imaginable form, to the ways of transport (car, aircraft). These general conceptual metaphors had been unfolded in other s more specific ones ( animal specifying itself in lion , dragon , dog , etc.). Another result was the identification of metaphoric expressions with two or more meanings , with relation to more than one conceptual metaphor or explicit, in the same expression, two domains-source (for example: armored dragon ) and contributes, of a relevant form, for the semantic struturation of the text. The understanding of the metaphors was verified through an activity of domains-source s identification (10 metaphoric statements and fulfilling of the gap in the phrase the inflation is a/an ) applied in a group of 8th year of the basic education (12-13 years old, with 14 girls and 17 boys) from a school of good social and economic positions from Natal-RN. There weren t great difficulties on the part of the students in recognizing the domains-source involved: about 80% to the great majority of the statements
Resumo:
The fish, Hoplias malabaricus (Osteichthyes: Erythrinidae) and armored catfish, Hypostomus pusarum (Loricariidae) are of freshwater origin from the neotropical region, and are considered ecologically and economically of important. This work investigated the trophic strategies, the morphology and histology of the digestive tract of these fish captured from the Marechal Dutra reservoir, Acari, the semiarid region of Rio Grande do Norte, Brazil. A total of 133 individuals of H. malabaricus and 118 specimens of H. pusarum were analyzed. The two study species occupy different levels in the food chain and spatial distribution in the water column of the reservoir. The results of this study are presented in the form of four scientific papers. The first article describes the morphology and histology of the digestive tract and the feeding habits of H. malabaricus (Bloch, 1794). This fish has a short intestine, with an intestinal coefficient of 0.72 ± 0.09. The dietary importance index indicates that H. malabaricus feeds preferentially on animal matter, especially on fish (72.8%) and prawns (27.2%). The histology of its digestive tract confirms the carnivorous feeding habit. The second article discusses about the pioneering work on the feeding strategy and the characterization of anatomy and histology of the digestive tract of H. pusarum. The intestine of this fish is long, with an intestinal coefficient of 10.8±0.7. The dietary importance index indicates that H. pusarum feeds preferentially on organic matter in decomposition (88.7%) and on filamentous microalgae and diatoms (11.3%). The third article compares the morphological aspects of the digestive tract of H. malabaricus and H. pusarum, in relation to their food habits. The arrangement of the digestive organs in both species is directly related to the shape of the peritoneal cavity and the form of the body. The short intestine of H. malabaricus and the long intestine of H. pusarum are associated with their feeding habits. The morphology of the digestive tracts of H. malabaricus and H. pusarum confirm their food habits, carnivorous and detritivorous / herbivorous, respectively. The fourth article discusses the food and reproductive aspects (length and weight, length-weight relationship, type of growth and sex ratio) of H. pusarum. This species has a negatively allometric growth, with the predominance of females in the sampled population. H. malabaricus inhabits the pelagic environment and is a carnivore, while H. pusarum, lives in the benthic environment and is characterized as a detritivore/herbivore. Each species studied shows a very different diet, without trophic competition between them. The morphological and anatomical structures of the digestive tract reflect their feeding strategy.