Aquaponics fish. Image credit: Klaus Friese (Flickr)
June 25, 2018 Fish 5,777 Comments

…Well, that’s a sentence we never thought we would write.

According to this National Geographic article, male Tilapia fish pee whenever they are looking to attract the ladies.

Tilapia have an amazingly complex social structure. They dig holes in the sand and the most dominant males stay in the centre giving them access to the females.

During this mating ritual the male tilapia pee a lot. In the more dominant males, scientists found a chemical similar to progesterone (the female reproductive hormone) in their urine. The more dominant the male, the greater amount of this hormone occurred.

Nearby females can detect this hormone and use it to decide who is the more dominant (and therefore more desirable genetically) to mate with.

Image credit: Klaus Friese (Flickr)

Aquaponics fish looking for love! Image credit: Klaus Friese (Flickr)

If all this wasn’t weird enough, the more dominant males can actually extend their bladders to produce and give off more urine. The pee hormone also helps prime the females reproductive system, causing her eggs to ripen.


When setting up your aquaponics system, you may want to consider having an all male-tank. Most commercially raised tilapia are male, not only because reproduction is messy and can cause fighting in the tanks (for any species of fish), but because the males grow big faster.

If you are planning to eat/sell your fish then this is when to start considering having both male and female. Breeding is rapid but beware: they can reproduce at a speed that can overwhelm your biofilter. One option to control the population is to introduce a couple of predator fish that will eat a lot of the young and therefore continually keep your tank under control. We know this sounds a bit barbaric!

For the National Geographic article about Tilapia Urine go here

For more information about tilapia, try this article

For mouth watering tilapia recipe inspiration (minus the urine) try here and here

For more information about aquaponics fish, try here and here

Written by Pippa Woodhead
Being a health-nut, London born Pippa has struggled to adjust to the lack of availability of lettuce and kale since re-locating to India. Previously naive to the extent of the worlds food struggles, she has now become obsessed with sustainability in food production and especially in India where it needs it the most (plus she’s also hoping to get her hands on some kale any day now). When she’s not writing for Aquaponics in India, she is usually found with her head in a book or in the kitchen experimenting with new vegetarian recipes.