The Yellowfishes of Southern Africa (Labeobarbus spp.) and the mudfishes will probably spawn when the river rises due to rain or because of artificial flow management that stimulates spawning through increased flow. These species spawn several times from late Spring to late Summer. When this happens you will notice schools of fish holding in extremely shallow water (less than 30 centimetres sometimes) with their fins and sometimes bodies out of the water and will only spook when you are almost on top of them. They will rub themselves on the rocks and against each other and splash when they spawn.
Spawning lasts for a few days and occurs on first rains or in mid spring (October normally), mid summer (normally December) and late rains or the latter half of summer (Feb/March). Spawning times can vary by up to a few weeks depending on where you are on the river so always be on the lookout.
A special word of thanks to Henry Gilby for use of the original image and edit for illustration purposes.
Please do not target or disturb spawning fish
Pic – http://yellowsonfly.blogspot.com/