Discus (genus Symphysodon)

FishCichlidAmazon

Overview

Discus are cichlids of the genus Symphysodon, native to the Amazon basin. Their body is laterally compressed into a near-circular disc — a shape that lets them slip between submerged roots and branches in the flooded forest they inhabit.

Wild discus are patterned in browns, greens, blues and reds with vertical bars that can darken or fade with mood. The intensely coloured varieties familiar from aquarium shops are the product of decades of selective breeding, not wild appearance.

Their most remarkable trait is parental: discus feed their newly hatched young on a secretion produced from the parents' own skin, with the fry grazing directly on the flanks of the adults for the first weeks of life.

Habitat & Range

Discus live in the Amazon basin in slow-moving blackwater and clearwater tributaries, floodplain lakes and flooded forest. They are strongly associated with submerged structure — root tangles, fallen branches and leaf litter — in soft, warm, often acidic water. Water chemistry and levels shift dramatically with the flood cycle, and discus move into flooded forest as waters rise.

Diet

Wild discus are omnivores that feed on small invertebrates, insect larvae, crustaceans, plant material and detritus taken from among submerged structure and the substrate. Their small mouths suit picking small items rather than taking large prey.

Behavior

Discus are social outside breeding, forming groups in the wild, and pair off to breed. Eggs are laid on a vertical surface such as a root or leaf, and both parents guard and fan them. Once the fry become free-swimming they attach to the parents' flanks and feed on the mucus-like secretion the adults produce for the purpose — the parents take turns, and the transition off this food onto other prey is gradual. This form of parental care is unusual among fishes.

Human Interaction & Conservation

Discus are among the most prized aquarium fish in the world and are the subject of extensive selective breeding for colour and pattern; virtually all trade animals are captive-bred. In the wild they are affected by habitat change in the Amazon basin, and taxonomy within the genus continues to be revised. This profile is educational and covers the wild fish — it offers no aquarium husbandry, water-chemistry, feeding or breeding advice. Verify current status at the IUCN Red List.