Радуга балықтары: тұщы су шағалаларының отбасысы

Family of fishes
the freshwater fish

Rainbowfishes are small, colourful freshwater fishes belonging to the family Melanotaeniidae, found in northern and eastern Australia, New Guinea (including islands in Cenderawasih Bay and Raja Ampat Islands in Indonesia), Sulawesi and Madagascar. The largest rainbowfish genus, Melanotaenia, derives from the ancient Greek melano (black) and taenia (banded). Translated, it means "black banded", and is a reference to the often striking lateral black bands that run along the bodies of those in the genus Melanotaenia.

The Melanotaeniidae is characterised by having their distal premaxillary teeth enlarged. They have a compressed body with the two dorsal fins being separated but with only a small gap between them. There are 3–7 spines in the first dorsal fin while the second has 6–22 rays, with the first ray being a stout spine in some species, the anal fin has 10–30 rays and, again, the first may be a stout spine in some species. The lateral line is either weakly developed or absent. They have comparatively large scales and these number 28–60 in the lateral series. The pelvic fins are attached to the fish's abdomen by a membrane which runs along the length of the innermost ray and this is a feature which can be used to separate rainbowfishes from silversides, although the membrane is easily torn. The majority of the species in this family demonstrate conspicuous sexual dimorphism, with the males usually being the more colorful sex and also showing an elongated median fin ray. Melanotaenia, Pseudomugil, and several other genera of rainbowfish include species that regularly appear in the aquarium trade. In the wild, some rainbowfish populations have been severely affected by the aggressive introduced eastern mosquitofish (Gambusia holbrooki), tilapia cichlids, and pollution.

Rainbowfish usually do best with tropical community fish, such as tetras, guppies, and other rainbowfish. However, two males may sometimes fight at breeding season if there are not enough females. Rainbowfish usually eat floating flakes in captivity, because in the wild they will often eat insects floating on the surface. In a home setting, these fish need well oxygenated water with a pH level of 6.8 7.2, optimal temperatures varying between 72 and 82 °F (22 28 °C), and plenty of aquatic plants to give them hiding places amid their school. If properly cared for, Rainbowfish can live up to 5 years in captivity.