The members of the Osphronemidae family are also called Gouramis or Labyrinth fish. What they have in common is that in addition to gills, they have an extra breathing organ: a fine labyrinth in which they compress air above water to breathe. This adaptation arose because they originally occur in stagnant, very warm and oxygen-free water. However, this has reduced the functioning of the gills. Even in oxygen-rich water they have to absorb air with their labyrinth above the water. If this is not possible, this fish may drown.
This family includes about 14 genera and 132 species.
The method of propagation of these species is interesting. They do this in two different ways.
The fish from the slightly faster flowing waters take the eggs in their mouths immediately after laying. The males incubate the eggs there. The young continue to develop in the mouth for a while until they can fend for themselves. After the little ones have been spit out, they are no longer cared for.
Foam Nest Builder
Things are often slightly different for fish that live in absolutely stagnant water. Here the men often build a bubble nest. By blowing bubbles, the men create foam in which the eggs can be hung. After an intense courtship ritual in which the fish often entwine each other, the women spawn. Some eggs have a light oil content and are therefore lighter than water, allowing them to rise automatically. In other species, the male must collect the eggs and spit them into the nest. These eggs usually hatch after about 24 to 48 hours. The young then remain in the nest for another two to three days until they can swim freely. The man is the one who guards the bubble nest. Once the young can swim freely, they are no longer cared for.