Gouramis are freshwater fish that belong to the family Osphronemidae, which consists of around fifteen genera with more than 95 species.
One such specie is the kissing gourami (Helostoma temminckii), which is the single species of the genus Helostoma in the family Helostomatidae. In fact, it is the sole species of this family and is otherwise known as the kisser or kissing fish.
Kissing gouramis are so named for their lip-locking activity.
Kissing fish are sometimes found to lock their lips with other members of the species. You may also find them kissing other types of fish, plants, and objects in the tank, while feeding or bullying. While there are various instances of animals displaying human behavior, what is the truth behind the 'kiss' of this fish? Why do kissing fish kiss?
Kissing gourami is a fish with fleshy, pouting lips, which is its characteristic feature. Compared to most of the other gouramis, this fish has a terminal mouth that can be protruded. Even the name of the family Helostomatidae is derived from this feature. Though the lip-locking act of these fish may appear as kissing, it is certainly not a display of love and affection, as in case of humans. It has been suggested that their lip-locking is a sign of fight for dominance. It usually happens in young males, who want to defend their territory or feeding areas. Such aggressive behavior is also seen during breeding season, to attract females.
In short, kissing fish do not kiss and display their love. What appears to be a kiss is actually a fight for dominance, in males. However, it is this feature that is responsible for the popularity of kissing gourami, which is commonly raised in aquariums.