Variações na morfologia ovariana e no desenvolvimento do folículo de peixes teleósteos da Bacia do Rio Paraná

Orientador: Prof. Dr. Angelo Antonio AgostinhoDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Curso de Pós-Graduação em ZoologiaInclui referências: p. 101-107Resumo: Resumo: Neste estudo são analisadas e comparadas as características morfológicas dos ovários e morfo-biométricas dos componentes do folículo ovariano de teleósteos da bacia do rio Paraná. Relações entre estas características e a estratégia reprodutiva e grupamentos taxonômicos são também estabelecidas. Os exemplares analisados foram obtidos em diferentes ambientes da bacia do rio Paraná, no trecho entre a foz do rio Paranapanema e a do Iguaçu. Secções transversais dos exemplares ao nível da cavidade visceral, cortes histológicos de ovários em diferentes fases de desenvolvimento e ovócitos dissociados foram utilizados nesta análise, sendo as comparações interespecíficas de cada característica considerada realizada para mesma fase ou mesmo estádio de maturação. As variações na morfologia ovariana estão relacionadas principalmente ao espaço disponível na cavidade visceral e às interações entre os requerimentos de espaço pela maturação cíclica e grupo taxonômico. O tamanho dos ovócitos, associado ao cuidado parental, relaciona-se com o número de nucléolos e diâmetro de grânulos de vitelo. As variações nas espessuras da zona radiata relaciona-se com o meio no qual os ovócitos são depositados e os ovos desenvolvem. A espessura da camada granulosa tendem a ser delgada nos Characoidei (exceto Schizodon nasutus e Apareiodon piracicabae) e mais espessa nos Siluroidei. Os diferentes tipos de inclusões observados nas células da granulosa podem estar relacionados aos diferentes graus de adesividade e/ou proteção dos ovos após extruídos. Observou-se dois padrões de desenvolvimento, o sincrônico em grupos e o assincrônico acumulativo e dois de desova, total ou parcelada por temporada. A análise de grupamento de 57 espécies conforme as variáveis do folículo ovariano revela formações de grupos de espécies com estratégias relacionadas.Summary: In this study were analyzed and compared the characteristics of the ovarian morphology and follicle morphometric components from Parana River basin' teleosts. Relationships between these characteristics, the reproductive strategy and taxonomic group were realized too. The individuals analyzed were obtained from different environments from the basin, in the stretch between the Paranapanema and Iguacu rivers. Transversals sections of the individuals at the visceral cavity, histological section of the ovary in different maturation phases or stage and disaggregated oocytes were used in this analyze. The inter-specifics comparison for each characteristic considered were made for the same maturation phase. The variations in the ovarian morphology are related mainly to the available space in the visceral cavity and to the interactions between the requirements of space by the cyclic maturation and taxonomic group. The oocytes' size, associated with the parental care, is related with the number of nucleolus and diameter of the yolk granula. The variations in the thickness of radiate zone related with the medium in which the oocytes are deposited and the eggs development. The thickness of the granullosa layer tends to be thinner in Characoidei (Except S.nasutus and A.piracicabae) and thicker in Siluroidei. The different inclusion kinds observed in the cells of granullosa may be related to different degrees of adhesivity and/or eggs protection after ovulated. It was observed two patterns of ovocitary development, synchronic in groups, accumulative asynchronic and two of spawn, total and parceled by period. The cluster analyses of the 57 species according to ovarian follicle variables revels a group arrangement of the species that have similar strategies

Ethnoknowledge on fish fishermen and teachers in the floodplain of the upper Rio Paraná

The research aimed to investigate the ethnoichthyologics there are fishermen’s knowledge region of the upper Paraná River, as well as analyze how teachers from area schools promote the dialogue between the scientific and popular knowledge with their students. The popular fishermen’s knowledge on fish was obtained through personal interviews. It was also developed an educational workshop and questionnaire applied to teachers, to identify the concepts and practices to teach them about the issue at hand. The data were analyzed by the technique of content analysis. The results indicate that the fishermen have ethnoichthyologics knowledge of the area, which should be considered in environmental education projects and management of local natural resources. Regarding the teachers, we found limitations for them work the dialogue of issue in their classes, though these were salved and reflected during the workshop

Colonization of the Corumbá Reservoir (Corumbá River, Paraná River Basin, Goiás State, Brazil) by the "lambari" Astyanax altiparanae (Tetragonopterinae; Characidae)

This work aimed to determine which population features were important to the colonization process of Astyanax altiparanae in the Corumbá Reservoir. The species presented wide spatial-temporal distribution, caught in all months and sites. Higher CPE values were recorded upstream from the reservoir during the filling phase. In this phase, reproductive activity was intense upstream and moderate in the tributaries. However, a fall in abundance of juveniles was observed after the formation of the reservoir. Among the most relevant population features to grant a successful colonization were wide geographic distribution, ability to occupy and spawn in lentic habitats and feeding flexibility