Introduction to Anabantids (Labyrinth Fish)

Interesting behavior, modest requirements together with their brilliant colors make the anabantoids among the most popular aquarium fishes. Originating from southern Asia and Africa, the anabantids are characterized by an accessory breathing structure in addition to gills for the absorption of oxygen.

Well known members of this family include the Betta, the Gourami, and the Paradise Fish. A common name for anabantoids (Anabantids, Anabantoidei) is labyrinth fish, derived from the auxiliary breathing organ. This organ, called the labyrinth organ, allows the fish to breathe oxygen from the air.

The labyrinth organ is located above the gills and occupies most of the gill chamber. Suffocation is possible in some species if they are prevented from breathing at the surface. Labyrinth fish can survive a short period of time out of water as long as they are kept moist.

Anabantids also have unique breeding behavior. The male builds a floating nest by blowing saliva coated air bubbles from his mouth. Eggs are deposited in the bubblenest by the female, and the eggs are aggressively guarded by the male until they hatch. Not all species build bubblenests, some are mouthbrooders, holding the eggs and fry in their mouth. Most anabantids are omnivorous allowing a wide range of food choices. Flakes and pellets are ideal, but live foods such as mosquito larvae and aquatic invertebrates can provide added benefits to their diet. Anabantids spend most of their time near the surface and as a consequence tend to be surface and mid-tank feeders.

Aquarists choosing to keep labyrinth fish encounter unique options as well as some challenges. Anabantids are tolerant of seemingly poor aquarium conditions. The fish are able to tolerate cooler temperatures as well as to survive in water with very low oxygen levels. These modest requirements allow some aquarists to keep the fish in tanks or bowls without heaters or filtration systems. However, the males of all species are territorial and can be aggressive, perhaps making some unsuitable for a community tank with fish like guppies, algae eaters and green terrors, however when mixing fish it’s best to consult with a marine biologist or aquarium expert before making a final decision.