Discus

Discus are gregarious fish that only thrive in groups. Although naturally calm, the discus is a cichlid: hierarchy is omnipresent in the group, manifesting itself at feeding, pair formation and spawning. Each spawning period is marked by contests that can be quite violent.

Like all Cichlidae of the genus Pterophyllum, all species of Symphysodon have a flat, laterally compressed shape. Unlike Pterophyllum, Symphysodon does not have these extensions of the fins in points that give the angelfish its characteristic chevron shape, and its overall appearance is more rounded. It is this disk shape that gave it its common name of discus. The adult fish reaches 20 cm or more, both in height and length. The sides of the fish are frequently marked with marbled motifs in green, red, brown or blue colors. Sexual dimorphism is very weak, the shape of the fins and the pelvic area would be more rounded in the female. The only fairly reliable criterion is the shape of the genital papillae during reproduction, which allows identifying the male from the female in an already formed couple: the papilla is more pointed in the male, and rounded in the female (but even this criterion is not always very obvious).

To study the diet of the Discus we will first define its needs.

The metabolism of fish is quite low, because they do not regulate their temperature. They also do not struggle against gravity, and their waste excretion mode in the form of ammonia is also energy-efficient since it requires no transformation. Maintenance needs are low. These needs still depend on the temperature of the tank, fish living in warmer water consume more energy. Similarly, the younger the fish and therefore in growth phase, the more energy they consume.