Labyrinth

Auxiliary respiratory organ which allows certain fish to use oxygen in the air.

The term "labyrinth" is used in the field of aquarophilia to designate a specialized organ present in certain fish, which allows them to breathe in aerial environment.

The labyrinth is a complex structure made up of thorny branches and narrow cavities. It is located inside the head of the fish, and is connected to the mouth by conduits called Nares. When the fish is in the water, it breathes mainly using its gills, that is to say specialized organs which allow gas exchange with water. However, some fish also have the labyrinth, which allows them to breathe in aerial environment when they are out of the water.

The functioning of the labyrinth is quite complex. When the fish comes out of the water and its gills are unusable, it sucks by its air by its nares and pushes it towards the labyrinth. The air then passes through the thorny branches and the cavities of the labyrinth, where it is mixed with venous blood. The blood loaded with oxygen is then distributed in the body of fish, while carbon dioxide is evacuated by the Nares.

It is important to note that only some fish have a labyrinth. This type of organ is mainly found in fish belonging to the families of anabantidae (such as gouramis) and osphronemidae (like catfish). These fish are often called labyrinth fish because they are able to breathe in aerial environment thanks to this specialized organ.

The labyrinth is a very useful organ for fish, which allows them to live in environments where oxygen is limited. However, it is important to make sure to maintain a good level of oxygen in the aquarium, so as not to put too much pressure on the labyrinth and allow the fish to breathe optimally.