Yes, but they will vary depending on the departure/destination point and the tariffs that were applied, although as a general rule we can say that:
Children older than two years and younger than twelve years of age at the moment the flights depart (child) travel paying 50% of the fare on domestic flights (flights within Spain) with full tariff (i.e. without restrictions). If this minor (baby or infant), is to reach his/her second birthday before the end of the journey, you will have to purchase a child fare ticket for the entire journey.
Children that still have not reached two years of age at the moment the flights depart (infant) and that don't occupy a seat pay 10% of the adult fare. These passengers may only travel with an adult.
If you want a child under two years of age (infant) to travel occupying a seat, the child will pay the tariff for children between 2 and 11 years of age (child), and will have to bring an approved child seat to travel in.
In addition, if an adult travels with two babies (infant), one will pay the corresponding (infant) tariff, travelling on the adult passenger's lap, but the second baby will pay the tariff for children between 2 and 11 years of age (child), as they occupy a seat (they must bring an approved child seat to travel in).
For reduced tariffs a percentage will be applied that will depend on the tariff chosen.
On international flights this percentage rate will vary depending on the destination and the tariff applied.
For some special offers no discount will be applied.