One of the special things about labyrinth fish, is that they do not get their oxygen through the water, but via their labyrinth like lungs (which is also the reason for the popular name of this type of fish) which means they can breathe oxygen from atmospheric air. This comes very handy as they often inhabit shallow and oxygen poor water areas.
Another peculiar thing is that many labyrinth fishes, including the Pearl gourami, build a nest of bubbles in the surface of the water and the spawning takes place under the nest and the eggs flows up into the nest. It is the male that builds the nest and it is also the male that guards the nest while the eggs hatches.
I haven't succeeded in getting my Pearl gouramis to spawn, but it is said to be quite easy. It can be an advantage to lower the water level in the tank as well as raising the temperature a degree or two. When spawning succeeds, the most important next step is to have sufficient foods for extremely small fry - it requires for instance a substantial infusoria production.
