Many gouramis have an elongated, feeler-like ray at the front of each of their pelvic fins. Many species show parental care: some are mouthbrooders, and others, like the Siamese fighting fish (Betta splendens), build bubble nests. Currently, about 90 species are recognised, placed in four subfamilies and about 15 genera.
The name Polyacanthidae has also been used for this family. Some fish now classified as gouramis were previously placed in family Anabantidae. The subfamily Belontiinae was recently demoted from the family Belontiidae. As labyrinth fishes, gouramis have a lung-like labyrinth organ that allows them to gulp air and use atmospheric oxygen. This organ is a vital innovation for fishes that often inhabit warm, shallow, oxygen-poor water.
In the aquariumEdit
Gouramis, particularly the three spot and dwarf, are often kept in home aquariums. As labyrinth fish, they will often swim near the top of the tank. As with other tropical freshwater fish, an aquarium heater is often used. Gouramis will eat either prepared or live foods. Some species can grow quite large, and are unsuitable for the general hobbyist.
Generally regarded as peaceful, gouramis are still capable of harassing or killing smaller or long-finned fish. Depending on the species, adult and juvenile males have been known to spar with one another. Aggression can also occur as a result of overcrowding.
Gouramis have been housed with many species, such as danios, mollies, silver dollars, and plecostomus catfish, but will often show aggression toward species with long, flowing fins like male guppies, goldfish, and bettas.