Gourami: why it needs free access to the water surface
The gourami belongs to the anabantoids, the same family as the Siamese fighting fish (betta), and shares with it a physiological trait rare among aquarium fish. Find our other equipment tips in the fish accessories section.
The labyrinth organ, a dual breathing system
In addition to its gills, the gourami has a labyrinth organ, a richly vascularised bony structure near the gills that lets it absorb oxygen directly from air. Research shows that this air-breathing ability strongly influences territorial behaviour, courtship displays and egg care in anabantoids (research on Google Scholar). Unlike the betta, in which this air-breathing is facultative, the gourami relies on it more heavily: regular access to surface air is not a detail, it is a physiological need.
What this means for the tank
Always leave a free air gap between the water surface and the lid, and avoid filling the tank right to the brim. A lid still remains essential: the gourami is a good jumper, just like other species covered in our guide on jumping fish and tank-lid safety.
A fish that prefers calm water
The gourami likes weak to moderate current: a filter that is too powerful tires it out and stops it swimming comfortably near the surface, where it sometimes builds a bubble nest to breed. Choose an adjustable filter or aim the outflow at the glass rather than at the surface area, following our notes on choosing an aquarium filter.
Frequently asked questions
Can a gourami drown if it cannot reach the surface?
Yes, a lid set too low or an excessive water level can genuinely suffocate it: always leave enough air space.
Does a gourami need an air stone like a betta?
No, its labyrinth organ is enough as long as it can breathe freely at the surface; an air stone remains optional for general tank oxygenation.
Why does my gourami often stay still at the surface?
This is normal behaviour linked to its air breathing, as long as the fish is otherwise active and feeding normally.
This guide is part of Planète Pets’s Fishkeeping universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.