A habitat is an area in nature in which a particular species is found. When describing a habitat, terms such as swamp, riverine, stream, rainforest, rocky, vegetated etc. may be used.
In fish keeping, recreating or representing the habitat in which a fish species may be found has a direct effect upon its health and wellbeing.
Fishes have evolved to suit the particular habitat in which they originate, and therefore feel safe in such an environment. If the aquarium in which a fish is kept is a vastly different environment to its natural habitat, the fish may become stressed, disorientated, and unable to behave naturally, which will result in ill health and even death.
Fish which come from a shaded, vegetated forest stream or pool habitat might prefer an aquarium with plenty of plants, hiding spots and shaded areas. These types of fish would not appreciate an open, barren aquarium with intense lighting. On the other hand, fish which come from fast-flowing high altitude rocky rivers, or large open rivers, will like plenty of swimming room and will not be bothered by intense light and a lack of vegetation.
Many fish will adapt easily to aquariums which are not akin to their natural habitats but it is useful to know what types of environment a fish comes from in order to provide the best possible conditions and to pick suitable tank mates.