Exposure to 17α,20β-dihydroxy-4-pregnen-3-one changes seminal characteristics in Nile tilapia,Oreochromis niloticus

This experiment was conducted to evaluate the seminal characteristics of Nile tilapia males exposed to water-borne 17α,20β-dihydroxy-4-pregnen-3-one (17,20βP). Male Nile tilapia (Oreochromis niloticus L.) were exposed to the steroidal pre-ovulatory pheromone 17,20βP, added to water at a concentration of 5×10−9 M. The pheromone-exposed males had higher sperm volume and concentration. In addition, the spermatozoa contained in the sperm had higher motility and the motility duration was longer than ethanol-exposed males (control group). The percentage of live spermatozoa was not affected by the treatments. Our results suggest that this pheromone can improve sperm quality characteristics and could become a non-invasive method for enhancing spawning in Nile tilapia.