Symphysodon, colloquially known as discus, is a genus of cichlids native to the Amazon river basin in South America. Due to their distinctive shape and bright colors, discus are popular as freshwater aquarium fish, and their aquaculture in several countries in Asia is a major industry.[1][2][3][4] They are sometimes referred to as pompadour fish.[5][6] Description[edit] Red turquoise discus Like cichlids from the genus Pterophyllum (angelfish), all Symphysodon species have a laterally compressed body shape. In contrast to Pterophyllum, however, extended finnage is absent giving Symphysodon a more rounded shape. It is this body shape from which their common name, "discus", is derived. The sides of the fish are frequently patterned in shades of green, red, brown, and blue. Some of the more brightly marked variants are the result of selective breeding by aquarists and do not exist in the wild.[15][16] Discus typically reach up to 12.3–15.2 cm (4.8–6.0 in) in length,[8][17] but captives have been claimed to reach 23 cm (9 in).[18] Adults generally weigh 150–250 g (5.3–8.8 oz).[16] There is no clear sexual dimorphism for this fish, but males may reach a larger size than females.[16] In breeding form varieties, solid red discus (red melon, red cover) females are generally redder than males.[ Behavior[edit] Discus with two of its young nearby Symphysodon are highly social, typically occurring in groups that may number many dozens of individuals, which is unique among cichlids of the Americas.[17] When breeding, the pair moves away from the group, possibly to reduce the risk of cannibalism of the young.[17] As for most cichlids, brood care is highly developed with both the parents caring for the young. Additionally, adult discus produce a secretion through their skin, which the larvae live off during their first four weeks.[19] During the first two weeks, the parents stay near their young allowing them to feed easily. In the last two they swim away, resulting in the young being gradually "weaned off" and starting to fend for themselves.[19] Although rare in fish, more than 30 species of cichlids are known to feed their young with skin secretion to various extent,[19] including Pseudetroplus and Uaru species.[20] Sexual maturity is reached in one year.[17] Symphysodon primarily feed on algae, other plant material and detritus (periphyton), but also eat small invertebrates. Invertebrates can make up 38% of the stomach content in wild S. aequifasciatus during the high-water season, but this decreases during the low-water season and year-round it is generally lower in the other species.[17] Unlike more predatory cichlids, Symphysodon have relatively long intestines typical of a herbivore or omnivore.[17] -~-~~-~~~-~~-~- Please watch: "Top 10 most beautiful fishes in the world" https://www.youtube.com/watch?v=8OEAaq_xotc -~-~~-~~~-~~-~-