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FRESHWATER FISH

THE LABYRINTH FISH

    Ever wonder how a Siamese Fighting Fish can survive in a small amount of water? Bettas accomplish this feat with a special organ called a labyrinth. This adaptation enables the fish to live in oxygen-deficient habitats, and even leave the water for short periods of time. 

   Webster defines a "labyrinth" as a maze, or something extremely complex, which is a good description of this organ. The many folds, or lamellae, located in the first gill arch have an intricate system of blood vessels and capillaries. This way the blood of the fish is brought into contact with the atmospheric oxygen trapped in the labyrinth. 

   The labyrinth adaptation is an extremely efficient one, even though it cannot replace the normal influx of oxygen through the gills. The interesting fact is that the Labyrinth fish, or Anabantoids, are dependent upon the labyrinth system because their gills have been weakened by restricted work through evolution. Anabantoids deprived of atmospheric air will eventually suffocate. 

This is why Gouramies, another species of Anabantoid, and other species of labyrinth fish such as crocodile fish, are "packed out" so lightly when we send them to our customers. Sometimes a hobbyist complain that when they got their bag of Gouramies home, the fish had gone to the bottom of the bag and died. They didn't die from ammonia or pH shock, but from suffocation. 

   The variation in the Anabantoid family is extreme. There are giants like the Osphronemus Gourami, growing to at least two feet in length, and then there's the very small Sparkling or Pygmy Gourami. Kissing Gouramis are vegetarian, compared to the predatory Ctenopoma from Africa. Most fish referred to as Gouramis and Bettas are bubblenest builders, but there are egg scatterers like the drab colored Anabas Testudineus, or Climbing Perch. Fortunately, most labyrinth fish are very beautiful, like the brightly colored Dwarf Gourami in all its color variations, as well as male Bettas. 

   There is a labyrinth fish for every hobbyists's aquarium. The next time you visit your favorite aquaria store, look around and see the species they carry.

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