Evolução do processo de espermiação em machos de Piau, Leporinus macrocephalus, hormonalmente induzidos à reprodução
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Data
2011-02-16
Autores
Muñoz Gutiérrez, Mario Esteban [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
As espécies reofílicas apresentam, de modo geral, suas gônadas desenvolvidas até estágios avançados de maturação, porém as etapas finais do processo reprodutivo, tais como, a maturação final dos ovócitos, a ovulação, a desova e a liberação de sêmen, somente são atingidas mediante tratamentos hormonais. No entanto, a reprodução induzida de Leporinus macrocephalus apresenta algumas particularidades. Mesmo com a aplicação de duas doses de hormônio, os machos de L. macrocephalus geralmente liberam uma quantidade muito reduzida de sêmen, que freqüentemente é insuficiente para os procedimentos de reprodução induzida. Assim, o objetivo principal deste trabalho foi avaliar a evolução do processo de espermiação em reprodutores machos de L. macrocephalus, submetidos a tratamento hormonal. Para tanto, foram realizados estudos histológicos da estrutura testicular e da via seminífera, com inclusão de tecidos em historesina e coloração com azul de Toluidina. Estudos ultraestruturais das células germinativas foram realizados com processamento do material para rotina de microscopia eletrônica de transmissão. Análise da via seminífera foi também realizada com a injeção de acetato de vinila nos ductos testiculares e posterior análise em microscopia eletrônica de varredura. Para análise do epitélio germinativo ao longo do processo de indução hormonal, as preparações histológicas foram destinadas para estudos morfométricos, com utilização de sistema de análise de imagens. Após o tratamento hormonal foram realizadas análises seminais para verificação do volume total de sêmen liberado, concentração espermática, tempo de ativação e sobrevivência dos espermatozóides. Os estudos morfológicos evidenciaram que a estrutura testicular de L. macrocephalus é do tipo tubular anastomosado, espermatogonial irrestrito com espermatogênese do tipo cística...
Rheophilic species present, in general, their gonads developed to advanced stages of maturation, but the final stages of the reproductive process, such as the final maturation of oocytes, ovulation, spawning, and release of semen, are only achieved with hormonal treatments. However, the induced breeding of Leporinus macrocephalus has some peculiarities. Even with the application of two doses of hormone, males of L. macrocephalus usually release reduced semen, which is often insufficient for procedures of induced spawning. Thus, the objective of this study was to evaluate the progress of spermiation in males broodstocks of L. macrocephalus, undergoing hormonal treatment. For this, were performed histological studies of testicular structure and the seminal pathway with tissue inclusion into historesin and staining with toluidine blue. Ultrastructural studies of the stems cells were performed with material processing for routine of transmission electron microscopy. Analyses of seminal pathway were performed with the injection of vinyl acetate in the testicular ducts and subsequent analysis of scanning electron microscopy. For analysis of the germinal epithelium throughout the hormonal induction process, the histological preparations were destined for morphometric studies using an image analysis system. After hormone treatment seminal analysis was performed to verify the volume total release of semen, sperm concentration, time activation and survival of spermatozoa. Morphological studies evidence that the testicular structure of L. macrocephalus is anastomosed tubular type, espermatogonial unrestricted with a spermatogenesis of cystic type. The seminal pathway of this species comprises the seminiferous tubules anastomosing, the main testicular duct and spermatic duct. The histologic and ultrastructural studies showed that the connection of the seminiferous tubules occurs in different segments... (Complete abstract click electronic access below)
Rheophilic species present, in general, their gonads developed to advanced stages of maturation, but the final stages of the reproductive process, such as the final maturation of oocytes, ovulation, spawning, and release of semen, are only achieved with hormonal treatments. However, the induced breeding of Leporinus macrocephalus has some peculiarities. Even with the application of two doses of hormone, males of L. macrocephalus usually release reduced semen, which is often insufficient for procedures of induced spawning. Thus, the objective of this study was to evaluate the progress of spermiation in males broodstocks of L. macrocephalus, undergoing hormonal treatment. For this, were performed histological studies of testicular structure and the seminal pathway with tissue inclusion into historesin and staining with toluidine blue. Ultrastructural studies of the stems cells were performed with material processing for routine of transmission electron microscopy. Analyses of seminal pathway were performed with the injection of vinyl acetate in the testicular ducts and subsequent analysis of scanning electron microscopy. For analysis of the germinal epithelium throughout the hormonal induction process, the histological preparations were destined for morphometric studies using an image analysis system. After hormone treatment seminal analysis was performed to verify the volume total release of semen, sperm concentration, time activation and survival of spermatozoa. Morphological studies evidence that the testicular structure of L. macrocephalus is anastomosed tubular type, espermatogonial unrestricted with a spermatogenesis of cystic type. The seminal pathway of this species comprises the seminiferous tubules anastomosing, the main testicular duct and spermatic duct. The histologic and ultrastructural studies showed that the connection of the seminiferous tubules occurs in different segments... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Peixe, Estrutura testicular, Indução hormonal, L. macrocephalus, Peixe neotropical, Fish, Testicular structure, Hormonal induction, L. macrocephalus, Neotropical fish
Como citar
MUÑOZ GUTIÉRREZ, Mario Esteban. Evolução do processo de espermiação em machos de Piau, Leporinus macrocephalus, hormonalmente induzidos à reprodução. 2011. 129 f. Dissertação (mestrado) - Universidade Estadual Paulista, Centro de Aquicultura, 2011.