Cryopreserved sperm for oocyte fertilization of dourado Salminus brasiliensis

Abstract

Salminus brasiliensis is a migratory fish that has attracted considerable interest for aquaculture. Several procedures for induced spawning are known; however, there is a lack of protocol which enables the use of cryopreserved semen. Therefore, this study was conducted to investigate the use of cryopreserved semen using different volumes of cryopreserved semen relative to oocytes, different activators solutions and different maintenance time during the fertilization of dourado to evaluate the impact of these parameters on the fertilization rate. The semen was collected, cryopreserved in 0.5mL straws and stored in a dry shipper. Oocytes samples were fertilized according to each treatment. The different activator solutions and the contact times of the gametes with activators affected significantly the fertilization rates, which ranged between 13.4 and 27.8%, while fresh semen fertility rate was 80.8%. The relationship between oocyte and cryopreserved semen was significant, being the best ratio 0.05mL of cryopreserved semen per 10g of oocytes, while upper or lower volumes promoted a reduction in fertilization. The use of cryopreserved semen was effective to fertilize S. brasiliensis oocytes, however produced lower fertility rate than fresh semen