Soluções iônicas e não iônicas na ativação e fertilização de espermatozoides criopreservados de jundiá (Rhamdia quelen)

Abstract

The objective of this study was to employ different ionic and nonionic solutions on the cryopreserved semen of jundiá (Rhamdia quelen) and to evaluate the effects on the fertilization rate. Semen from 24 broodstocks was collected for seminal and spermatic analyzes. After the procedures of analysis the semen of the breeders gave rise to four composite samples (semen pools). Then there was the container of semen in vial for cryopreservation. Sperm activation occurred after thawing, and eight solutions were used as the sperm activator, each with five different concentrations and the distilled water as control. The rates of motility, velocity, and activation time were assessed by multiple regression analysis under the response surface model. For the fertilization test, four matrices and 24 brooders were used. The semen of the reproducers of this trial was collected and cryopreserved. The matrices were induced by the application of 5.5 mg of carp pituitary extract (EPC) / kg. The gametes collected after 240 hours-degrees. Then fertilization of the oocytes with the inseminating dose of 70,000 spermatozoa / oocyte was performed. For the activation of the spermatozoa, seven solutions were used, each with two concentrations and the distilled water as control. Fertilization was evaluated by ANOVA and by means of tukey tests. All the solutions employed in this study had an effect on the spermatic movement. However, the best results were obtained using 3.6% glucose, which provided the highest rate of motility and speed of spermatozoa. In the fertilization test, among all the solutions employed glucose 3.60% had the highest fertilization. This effect is possibly due to the important role that glucose has in the process of cellular respiration and ATP production, which through glycolysis, glucose acts on the acceleration of the flagellar beating. The presence of sugar is associated with its rapid absorption from the external environment and its use as an energy source. Therefore, the use of the solution containing 3.6% glucose increased sperm movement and increased oocyte fertilization.