I'm in the dictionary next to Multi Tank Syndrome

Many anabantiformes have a labyrinth organ that allows them to breathe oxygen from the air. This is because they live in ephemeral habitats, where water sometimes dries up and/or becomes poorly oxygenated. These fish can gulp air from the surface of the water, or even move across land to find better habitat.

The Siamese Fighting Fish (Betta splendens) (image 1) is the most well-known Betta species, originally domesticated for fighting and now kept as pets worldwide. Unfortunately, their ability to breathe air and live in ephemeral habitats like marshes, floodplains, and rice paddies has led to them being categorized as an easy, low-maintenance pet that is used to living in “puddles”, and they (along with goldfish) are one of the most abused pet fish species. Uninformed Betta owners will keep them in bowls, vases, or tiny tanks without heat or filtration, with little to no enrichment. Nowadays, Betta breeders breed for quantity over quality, and the fish are farmed “puppy mill” style, leading to what should be an animal with a 10 year life expectancy being shorter-lived and prone to cancers and other health complications. And why would they breed for health, if most Bettas will die of suffocation in a bowl in a few months anyway? This is why, for any animal, it is always important to research their proper care first before getting them as a pet.

The Climbing Perch (Anabas testudineus) is a climbing gourami that can live without water for 6–10 hours and move on land by crawling/wriggling its body with its pectoral fins. It is believed that this species may be invading new territories by slipping aboard fishing boats.

Kissing Gouramis (Helostoma temminckii) (see gif above) are popular aquarium fish, named because of their highly protrusible, forward-facing mouths, which are used in a ritualized display of aggression that looks, to humans, like two fish kissing each other.

The Giant Gourami (Osphronemus goramy) has been used for weed control on highly invasive aquatic plants like Giant Salvinia (Salvinia molesta), as the Giant Gourami can be a voracious herbivore.

The Pikehead (Luciocephalus pulcher) is a specialized ambush predator that spends most of its time lying hidden and motionless for potential prey to approach, a rare strategy for gouramis. The Pikehead is able to extend its jaw to about one-third of its body length, allowing it to successfully prey upon fishes almost half of its own length. This large, extendable mouth also has a more gentle use, as male Pikeheads are mouthbrooders.

Most Anabantiformes practice paternal care, whether the males make a floating nest or brood their eggs and young larvae in their mouths. The Chocolate Gourami (Sphaerichthys osphromenoides) is unique in that females are the ones to incubate their eggs in their mouths, instead of the males.

While many gouramis, especially males, are known for being territorial and aggressive, Dwarf Gouramis (Trichogaster lalius) have a reputation in the aquarium trade for being so docile that they will allow themselves to be bullied to death rather than fight back.

The Fork Tailed Paradisefish (Macropodus opercularis) was the second Chinese ornamental fish introduced to the West after the Goldfish (Carassius auratus), and the first freshwater tropical fish successfully bred in captivity in Europe, in 1869.

Croaking Gouramis (genus Trichopsis) have the ability to produce a distinctive croaking or clicking sound. This sound, often associated with courtship rituals or territorial disputes, is produced by the fish’s pectoral muscles.