Kissing gourami

The kissing gourami (Helostoma temminckii) is a medium-sized labyrinth fish native to slow-moving and standing waters across mainland Southeast Asia and the Greater Sunda Islands, including Thailand, Vietnam, Cambodia, Malaysia, Sumatra, Borneo, and Java. It is the sole member of the family Helostomatidae and is distinguished by its highly protrusible mouth lined with horny teeth, which it uses to graze biofilm and algae from hard surfaces. Reaching up to 30 cm (12 in) in total length, this deep-bodied, laterally compressed fish occurs in two colour morphs: the wild greenish-silvery form with spotty stripes and the pink leucistic variant produced through selective breeding that is among the most widely traded aquarium fish worldwide.

Kissing gouramis require a spacious aquarium of at least 304 L (80 gal) with a base measuring 150 x 45 cm or larger. The tank should provide ample open swimming space along with driftwood branches and roots for biofilm grazing. Tough-leaved plants such as Anubias or Microsorum are recommended, as these fish may pick at softer vegetation. Filtration must be efficient to handle their substantial waste output, but water flow should not be excessive. Weekly water changes of 30-50% are essential, and the tank should not be filled to the top since this species requires periodic access to the water surface to breathe atmospheric air. Temperature should be maintained at 22-30C (72-86F) with pH 6.0-8.0 and a broad hardness tolerance.

Kissing gouramis are specialised microphagous filter-feeders: they possess very fine gill rakers and primarily consume algae, biofilm, plankton, and fine particulate matter and can also accept soft flakes and small pellets. In the aquarium they should be offered finely crushed vegetable flakes, spirulina-based powders, and blanched vegetables, supplemented with small live or frozen foods such as Daphnia and Artemia. They are generally peaceful toward other large fish but can be territorial with conspecifics, especially in confined spaces. There is no reliable external sexual dimorphism, and breeding in captivity is challenging due to the difficulty of sexing. Aquarium lifespan estimates are around 15 years with suitable care.