1. Before spawning, the male fish chooses a calm and sheltered place on the water surface, inhales air and spits out mucus to form bubbles. Numerous bubbles stick together to form a floating nest with a raised or slightly flat surface. When male fish and female fish excrete eggs and sperm respectively, because the eggs are heavier than water, the eggs sink in the water. At this time, the male fish waiting below caught them with their mouths, coated the eggs with a layer of mucus, and went upstream to stick the eggs under the floating nest. A pair of parent fish lay 200 eggs at a time, the fertilized eggs hatch in about 36 hours, and the larvae can swim freely 3 days after hatching.
The male fish takes good care of his children, which can be described as relatives. In addition to building a bubble nest before spawning, it does not rest for a moment when the fish eggs hatch. Sometimes it picks up the fallen grains, sometimes it maintains the bubble nest, and often swims around the bubble nest to guard against possible invading enemies. After the small betta can live independently, the male betta can be fished out of the breeding box and fed.