Fork Tailed Paradisefish

Paradise fish are tolerant of a wide range of water conditions, surviving in cool and warm waters alike. In the wild, they are most commonly found in shallow water containing dense vegetation, such as a marsh or rice field. They can be kept in outdoor ponds or even the simplest of unheated aquaria. They accept virtually any food, but should be given a reasonably high-protein diet (as opposed to vegetable-based foods.) They also eat mosquito larvae, black worms, brine shrimp, and small flies.

Paradise fish are fairly combative, harassing and attacking each other, as well as potentially assaulting and killing small fish. During a fight, the paradise fish often changes its color, usually displaying dark blue lateral lines on the sides of its body, extends its fins, and spreads out its operculum. Paradise fish are more likely to show aggressive behavior towards other paradise fish than to fish of a different species. Acts of aggression tend to increase as the distance to the fish's home in Asia increases. In the wild, they are predators, eating insects, invertebrates, and fish fry. The popularity of this species has waned in recent decades, as much more colorful (and often less aggressive) species of gouramis have become widely available to hobbyists. This species is one of the few fish that can change its color (lighter or darker) in response to stimuli. Also, paradise fish apparently are capable of learning through a type of restrictive process. Most forms of active teaching seem to hinder the paradise fish's ability to learn the movements of its owner by careful observation.