The objective of this research was to verify the presence of spermatic abnormalities on semen of Brycon orbignyanus after cryopreservation. Semen was collected from ten four-year-old males who presented secondary reproductive characteristics for migrating fish. Sperm was evaluated for motility, vigor and spermatic morphology before and after cryopreservation. A cryoprotectant solution was made of 20 mL of yolk egg, 5.0 g of glucose and dimethyl sulfoxide diluted in distilled water (10 mL: 90 mL). The diluted semen (1:3, semen:solution) was submitted to nitrogen steam for 24 hours and then to liquid nitrogen (-196 °C) for 60 days. Cryopreservation decreased the percentage of normal spermatozoa from 62.20% to 54.60%. Consequently, the percentage of spermatozoa with secondary abnormalities increased from 8.50% to 15.00%. However, there was no difference in primary abnormalities. Both spermatic motility and vigor were decreased in cryopreserved semen compared with fresh semen. In conclusion, cryopreservation of semen of B. orbignyanus increased the percentage of secondary abnormalities and decreased the spermatic motility and vigor.Keywords: freezing, spermatozoa, morphology, Bryconinae. Anormalidades espermáticas de piracanjuba Brycon orbignyanus(Valenciennes, 1849) após a criopreservação ResumoO objetivo deste trabalho foi verificar a presença de anormalidades espermáticas no sêmen de Brycon orbignyanus após a criopreservação. Dez machos com quatro anos de idade e que apresentavam características reprodutivas secundárias para peixes migradores tiveram o sêmen coletado. O sêmen foi avaliado através da motilidade, vigor e morfologia espermática antes e após a criopreservação. A solução crioprotetora continha 20 mL de gema de ovo, 5,0 g de glicose e dimetil sulfóxido diluído em água destilada (10 mL: 90 mL). O sêmen diluído (1:3, sêmen:solução) foi submetido ao vapor de nitrogênio por 24 horas e então ao nitrogênio líquido (-196 °C) por 60 dias. A criopreservação reduziu o percentual de espermatozoides normais de 62,20% para 54,60%. Consequentemente, o percentual de espermatozoides com anormalidades secundárias aumentou de 8,50% para 15,00%. Porém, não foi observada diferença nas anormalidades primárias no sêmen "in natura" e pós-criopreservação. Ambos motilidade e vigor espermático foram inferiores aos observados no sêmen "in natura". Conclui-se que a criopreservação do sêmen de B. orbignyanus aumentou o percentual de anormalidades secundárias e reduziu a motilidade e o vigor espermático.Palavras-chave: congelação, espermatozoide, morfologia, Bryconinae.
In this work, the seminal parameters of P. mesopotamicus were evaluated fresh and after cryopreservation, focusing on the sperm variables that affect the rates of fertilization, hatching and post-hatching parameters such as larval survival and morphology. The semen and oocytes from the animals were collected after extrusion, and seminal quality and oocyte fertilization were analyzed. Subsequently, a portion of each semen sample was cryopreserved and, after two days, the oocytes from three new females were fertilized with cryopreserved semen from the males. The analyzes showed that progressive motility, spermatic vigor, motility duration, number of normal sperm and secondary abnormalities were higher in fresh semen than in semen after thawing (P <0.0001). Similarly, fertilization and hatching rates and the percentage of normal and abnormal larvae in fertilized oocytes were higher when fresh semen was used (P <0.0001). The cryopreservation process affected the qualitative parameters of the semen of Piaractus mesopotamicus. The primary abnormality of spermatozoa was the main variable that influenced both fertilization and hatching rates, both in fresh and thawed semen. The second most important variable that influenced, particularly, thawed semen, was the spermatic vigor.
In recent years, the genetic monitoring of broodstocks in fish farming has been greatly highlighted due to its importance in the management and improvement of their production and conservation. Current study evaluates the genetic diversity of four Tambaqui broodstocks (Colossoma macropomum) in the state of Rondônia (Brazil) and discusses activities towards the species´s correct production management and conservation. Nine primers were employed to analyze 94 specimens from four fish farms in the municipalities of Ji-Paraná (JP), Ouro Preto do Oeste (OP), Presidente Médici (PM) and Rolim de Moura (RM). Differences in the frequency of 38 fragments, with an exclusive fragment in JP and OP, were reported. High polymorphism (52.40 to 64.60%) and Shannon Index (0.313 to 0.382) rates were observed. The analysis of molecular variance (AMOVA) demonstrated that most variation is within each stock. The identity and genetic distance between the groups ranged between 0.927 and 0.954 and between 0.047 and 0.076 respectively, with shortest distance between the OPxPM and JPxRM groups. Genetic differentiation ranged from moderate to high (Fst = 0.081 to 0.179) and the number of migrants per generation was moderate (Nm = 3.83 to 6.24). As a rule, stocks showed high genetic variability and moderate / high differentiation and genetic distance between them. The results allowed direct conservation programs and increase the productivity of this species in fish farming through breeding programs. ResumoNos últimos anos, o monitoramento genético de estoques na piscicultura tem recebido grande destaque devido a sua importância no gerenciamento e melhora da sua produção e conservação. Dessa forma, o objetivo deste estudo foi avaliar de forma inédita a diversidade genética de quatro estoques de reprodutores Tambaqui (Colossoma macropomum) do estado de Rondônia (Brasil) e através dela, discutir ações que contribuam com o correto manejo produtivo e conservação dessa espécie. Utilizaram-se nove iniciadores para analisar 94 indivíduos de quatro pisciculturas dos municípios Ji-Paraná (JP), Ouro Preto do Oeste (OP), Presidente Medici (PM) e Rolim de Moura (RM). Foram encontradas diferenças nas frequências de 38 fragmentos, com um fragmento exclusivo em JP e OP. Altos valores de polimorfismo (52,40 a 64,60%) e índice de Shannon (0,313 a 0,382) foram observados. A análise de variância molecular (AMOVA) demostrou que a maior parte da variação está dentro de cada estoque. A identidade e distância genética entre os agrupamentos variou de 0,927 a 0,954 e 0,047 a 0,076, respectivamente, com menor distância entre os agrupamentos OPxPM e JPxRM. A diferenciação genética variou de moderada a alta (Fst = 0,081 a 0,179) e o número de migrantes por geração foi moderado (Nm = 3,83 a 6,24). De forma geral, os estoques apresentaram alta variabilidade genética e moderada/alta diferenciação e distancia genética entre eles. Os resultados permitirão direcionar programas de conservação e aumentar a produtividade dessa espécie na piscicultura através de program...
The study aimed to analyze the Colossoma macropomum reproductive behavior and quality of the female gametes throughout the reproductive season. The experiment was carried out in Pimenta Bueno -Rondônia State (Northern Brazil) during the reproductive season (2010-2011) using 36 females. Each sampling was performed on a 15 ± 5 days interval. Female gametes were collected by stripping and the following analyses were performed: weight of oocytes released (g); productivity index, fertilization and hatching rate. During the sampling period was verified effect (p < 0.05) of collecting time into the season for oocytes weight, productivity index and fertilization rate. Although the period 3 (December) did not differ significantly from other periods, it showed better parameters for the quality of C. macropomum oocytes.Keywords: Characidae, fertilization rate, oocytes, reproduction, reproductive period. Qualidade ovocitária de tambaqui (Colossoma macropomum) ao longo da estação reprodutivaResumo O estudo foi conduzido com o objetivo de analisar o comportamento reprodutivo da espécie Colossoma macropomum, quanto à qualidade de seus gametas femininos ao longo da estação reprodutiva. O experimento foi executado em Pimenta Bueno-Rondônia durante a estação reprodutiva do C. macropomum. Utilizaram 36 fêmeas durante a estação de 2010-2011. Cada coleta apresentou um intervalo de 15±5 dias. Através da extrusão foram coletados os gametas femininos e realizadas as seguintes análises ao longo da estação: peso de oócitos liberados (g); índice de produtividade; taxa de fertilização e eclosão. Durante a estação 2010-2011 foi verificado efeito (p < 0,05) de período (coleta) dentro da estação para peso de oócitos, índice de produtividade e taxa de fertilização. Apesar do período 3 (coleta -mês de dezembro) não ter diferenciado significativamente de alguns períodos, foi o que apresentou os melhores parâmetros estabelecidos para a qualidade dos oócitos de C. macropomum.Palavras-chave: Characidae, taxa de fertilização, oócitos, reprodução, período reprodutivo.
-The objective of this work was to evaluate the effect of different cryoprotectants on the viability of dourado (Salminus brasiliensis) embryos. Ten cryoprotectant solutions were tested. For each solution, 300 embryos were selected at the closing of the blastopore stage, and 300 more embryos were used as a negative control. After cooling (-8°C for 6 hours), the embryos were rehydrated directly in the incubator until hatching. The best result is obtained with the cryoprotectant solution containing 9% methanol associated with 17% sucrose, resulting in a larvae hatching rate of 67.06%.
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