Heckel discus

Care at a glance

Overview

This is the most demanding discus and not a beginner fish, so go in knowing it needs more than most tropicals. Keep a group of six or more in a tall tank of at least 284 liters, which spreads out the squabbling that comes with their pecking order. They are mostly peaceful and hold in the middle of the water column, but they need warm water at 28 to 31 C, very soft and acidic at pH 5 to 6.5, and frequent large water changes to stay healthy. Feed them a varied diet of frozen bloodworms, beef heart mixes, and quality pellets, several smaller meals a day. Keep tankmates calm and tolerant of the heat, or run them as a species-only group.

In the wild

Heckel discus come from the lower Rio Negro and its blackwater tributaries in the Brazilian Amazon, water that is very soft, acidic, and stained dark with tannins from leaf litter and botanicals. To match that, give them a tall tank running warm at 28 to 31 C with a pH down between 5 and 6.5, which usually means RO water remineralized low and tannins added from dried leaves or alder cones. Use a dim setup with driftwood and some botanicals on the bottom, since open glare stresses them. Keep the water pristine, because they will not tolerate buildup of waste in soft acidic conditions.

Good to know

This is a cichlid in the family Cichlidae, reaching around 18 cm as an adult. They are substrate-spawning egg layers that guard the eggs and let fry graze on a mucus the parents produce on their flanks, though wild Heckel are very hard to breed in the aquarium. Most fish in the trade are wild-caught rather than tank-bred, which is part of why they are so demanding. A healthy discus can live well over a decade with good care.

Did you know

Heckel discus carry a heavy dark vertical bar running down the middle of the body, the fifth bar, which is bolder than on other discus and is how hobbyists tell them apart at a glance. The trade still leans on wild-caught Heckel because they have resisted captive breeding far more stubbornly than the common discus lines, so the fish you buy often started life in a Rio Negro tributary.

Related species

• 

  Discus

  Symphysodon aequifasciatus

  7.9 in (20 cm)65 gal (245 L)79–90°F (26–32°C)

• 

  Altum angelfish

  Pterophyllum altum

  7.1 in (18 cm)45 gal (170 L)79–90°F (26–32°C)
• Black acara

  Cichlasoma bimaculatum

  7.1 in (18 cm)40 gal (150 L)68–82°F (20–28°C)

• 

  Blood Parrot Cichlid

  A. citrinellus x V. synspilum

  7.9 in (20 cm)32 gal (120 L)72–82°F (22–28°C)

• 

  Threadfin acara

  Acarichthys heckelii

  7.9 in (20 cm)53 gal (200 L)75–86°F (24–30°C)

• 

  True severum

  Heros severus

  7.9 in (20 cm)75 gal (285 L)79–86°F (26–30°C)