Phenacogrammus aurantiacus (golden Congo tetra) males sparring

Last week I added 14 more Phenacogrammus aurantiacus to my tank. The new golden Congo tetras are mostly female, whereas the ones I had before were only males. The males like having the females around and have stopped bullying each other on a daily basis. After today’s water change, the two biggest males started doing this dominance display. The massive number of bubbles (pearling) coming off the plants is a result of the water change, too. The other fish visible in the video are Alestopetersius smykalai. These two species school together peacefully.