Avaliação dos parâmetros seminais de pacu (Piaractus mesopotamicus) e sua correlação com as taxas de fertilização, eclosão e morfologia das larvas

• Autor(a) principal: Galo, Juliana Minardi
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Estadual de Maringá (RI-UEM)
• Texto Completo: http://repositorio.uem.br:8080/jspui/handle/1/1670
• topic: Pacu; (Piaractus mesopotamicus); Fertilização e eclosão; Parâmetros seminais; Morfologia espermática; Anormalidade espermática; Qualidade espermática; Brasil.; Pacu; (Piaractus mesopotamicus); Fertilization and hatching; Seminal parameters; Sperm morphology; Sperm abnormality; Sperm quality; Brazil.; Ciências Agrárias; Zootecnia

The objective in this work was to identify through the parameters of quality of the pacu semen (Piaractus mesopotamicus), of the fertilization rate, hatching and morphology of the larvae, indexes that allow certifying the animal with the best reproductive characteristic.Besides, to find possible correlations among the parameters qualiquantitative of the semen with the fertilization rate, hatching rate, and with the larval morphology, coming of eggs fertilized with semen "in natura" and frozen. A total of 42 males and 16 females of P. mesopotamicus were used to evaluate the correlations among the seminal parameters with it rates of fertilization, hatching and morphology of the larvae. Through the extrusion the semen and the egg were collected, and appraised the seminal quali-quantitative parameters, and accomplished the fertilization of the eggs. According to the value of the percentage of the fertilization rate of each crossing (maleXfemale), the females were classified as: "good females" - with fertilization taxes ? 70% and "bad females" - with fertilization taxes <70%. The quali-quantitative parameters of the semen didn't present statistical difference (P>0.05) in relation to the groups of "good and bad" females. Only the percentage of bent tail was larger (P <0.05) in the semen that fertilized the egg of the group of "good females", and broken tail was larger (P <0.05) in the semen that fertilized the group of the "bad females". The fertilization rate, hatching and percentage of normal larvae were larger (P <0.01) in the group of the "good females". Already the percentage of wasted eggs, larvae no emerged alive and no emerged died, it was larger (P <0.05) in the group of "bad females". Defective and dead larvae didn't differ (P>0.05) among the two groups. The main correlations found in the group of the "good females" were: progressive motility with primary abnormalities (r=-0.23; P=0.07). Spermatic concentration with hatching rate (r=0.25; P=0.05) and with wasted eggs (r=-0.34; P=0.007). The correlations found in the group of the "bad females" were: motility duration with coiled tail (r=-0.35; P=0.04) and spermatic concentration (r=-0.67; P <0.0001); wasted eggs and spermatic xvi concentration (r=0.33; P=0.05). Already for the study of the quality seminal evaluation "in natura" and frozen and its correlation with the fertilization rate, hatching and morphology of the larvae, six males and six females of P. mesopotamicus were used induced with extract of carp pituitary. After the evaluation of the seminal parameters, a bracket of each collected sample was cryopreserved and later thawed. In the semen "in natura", motility, spermatic vigor, duration of the motility, normal spermatozoa and secondary abnormalities were larger (P <0.0001). The averages of the fertilization rate and hatching, percentage of normal larvae and defective larvae of the eggs fertilized with the semen "in natura", were larger (P <0.0001) in relation to the thawed semen. Correlation was just verified among quali-quantitative parameters of the semen "in natura" and thawed for: duration of the motility with spermatozoa of degenerate tail (r = -0.77; P=0.0002) in the semen "in natura" and (r = -0.54; P=0.01) thawed. Correlations of the quali-quantitative parameters of the semen "in natura" were not observed and thawed with the fertilization rate, hatching rate, wasted eggs and defective larvae. As for the run across results, it is ended that the found correlations can auxiliary in the previous evaluation of the semen and of the males, because you encourage with smaller indexes of spermatics abnormalities possess a progressive motility and its higher duration, possibly causing a larger fertilization rate. Beyond of that fact, if the quality of the egg is not good, so that it causes a better fertilization rate, the quality of the semen needs to present good indicators of the parameters. The quality seminal raised the primordial being except using egg of good quality. The quality spermatic was influenced by the freezing process, including the spermatic morphology in the semen of P. mesopotamicus, taking the alteration in the fertilization rate and hatching.