Breeding Discus

How to breed Symphysodon: pair formation, vertical-surface spawning, biparental care, the unique 'discus milk' skin secretion that feeds the fry, and rearing them.

Overview

The Discus (Symphysodon) is a substrate-spawning cichlid of advanced breeding difficulty. Breeding pairs move away from their social group, possibly to reduce cannibalism of the young, and sexual maturity is reached within about a year.

Sexing

Discus show no sexual dimorphism under about 4 inches in size, making juvenile sexing unreliable. Adult clues include dorsal-fin shape, body size and lip thickness, though none of these characteristics is a guaranteed indicator of sex.

Conditioning the Breeders

Pairs are typically obtained by raising a group of juveniles until two fish bond and spawn after a period of conditioning. A breeding cone, slate tile or other clean vertical surface is provided as a spawning site.

Breeding Setup & Spawning

Eggs are laid on vertical surfaces. Reported breeding conditions in a successful spawn include around pH 6.8, hardness about 4 °, and a temperature near 29 °C, with the female laying batches of eggs (on the order of dozens) that the male then fertilises.

Egg & Fry Care

Both parents fan the eggs, remove infertile ones and guard the spawn. Eggs hatch in roughly two to two-and-a-half days. The most distinctive feature is parental skin secretion, known as 'discus milk', on which the larvae feed for about the first four weeks; fry graze directly off the parents' bodies. After about five days they can take baby brine shrimp, and parental feeding underlies the high survival of parent-raised fry compared with artificial rearing.

Common Challenges

Pristine water and frequent large water changes are essential for fry survival. Dominant or inexperienced fish may cannibalise early spawns, sometimes requiring a divider to protect the pair, and artificial rearing without parental mucus gives much lower survival.