Introduction to Discus Fish

Discus fish is the most beautiful of all tropical fish which is also known as Cobalt Discus, Blue Discus, Blue Faced Discus, Blue-Head Discus, Red Thunder Discus etc. They are also sometimes called the King of Aquarium fish. It is native to the Amazon River basin and its natural range extends down the Rio Solimões and along the main Amazon River between the Rio Putamayo in Colombia and Peru as far as the Rio Tocantins drainage in Brazil. It inhabits in the still or slow moving, soft, acidic waters and they prefer to live in deep sheltered areas around tree roots and rocks. It is a very friendly fish and it is often found in large groups in their native habitats and it likes to stay in the shadow during the day.

Discus fish’s Overview

It is one of the most popular ornamental fish species in the world. Body is almost circular or disc shaped with strong lateral compression. It has small mouth with a steep rising forehead, small bright red eyes and large extended fins. The body has nine dark and vertical stripes and their body base colors usually range from dark brownish to blue and green hues. They are also spotted and striated with blotches of black, yellow and red pigmentation. Dorsal and Anal fins are rounded with a long base while the caudal fin is indented and the pelvic fins are saber shaped.  It is a carnivore fish and in wild condition, it mainly feeds on small fish and fry along with larvae, other aquatic insects and invertebrates such as worms. It prefers water chemistry with pH of 6.0-6.5, water hardness of 10 – 150 dGH and water temperature of 82.0 to 88.0° F. It can grow up to 22 cm in length and 250 grams in weight. It can live up to 10 years or more.

Scientific Name: Symphysodon aequifasciatus

Common Name: Cobalt Discus, Blue Discus, Blue Faced Discus, Blue-Head Discus, Red Thunder Discus

Origin: Amazon River Basin

Adult Size: up to 22 cm

Behavior: Peaceful

Tank Level: All

Minimum Tank Size:  50 gallons

Diet: Carnivore

Breeding: Egg layer

Care level: Moderate to Difficult

Water pH: 6.0-6.5

Water Hardness: 10 – 150 dGH

Water Temperature: 82.0 to 88.0° F

Water Movement: Moderate

Lighting:  Moderate – normal lighting

Lifespan:  10 years or more

Background of Discus Fish

The Discus was first described by Dr. Heckel in 1840 and it was first imported into the United States and Europe in 1930 and 1940, respectively. It belongs to the family Cichlidae under order Perciformes of class Actinopterygii.  According to Fishbase, there are three species of discus fish such as Symphysodon aequifasciatus – Blue Discus, Symphysodon discus– Heckel or Red Discus and Symphysodon tarzoo– Tarzoo Discus. Today, the Discus is listed as a Threatened species in the IUCN Red Data List due to over exploitation.

Feeding Discus Fish

Discus are a carnivore fish and in wild condition, they mainly feeds on small fish and fry along with larvae, other aquatic insects and invertebrates such as worms.  In captive condition, generally they accept a wide variety of all kinds of live and frozen foods such as live brine shrimp, bloodworms, chopped beef heart and white worms. It also eats Tetra Min flakes, Tetra Color Bits, Tetra Prima, spirulina flakes, spinach, discus pellets and small fish. Feed should be supplied 2-3 times a day.

Housing Discus Fish

The Discus fish is one of the more difficult tropical fish to keep and it is not recommended for beginners. This fish requires 50 gallons aquarium with good water movement along with strong and efficient filtration. Carbon filtration can help maintain water quality. Discus fish prefers excellent water conditions with warm, soft and slightly acidic water. The tank should have an open area for swimming with some aquatic plants like the Dwarf Lily Bulbs, Water Onions, Ozelot Swords, Rangeri Swords and fern and moss type plants like the Java Fern and Subulata. It is a schooling fish and should be kept in groups of around 6 individuals or more. Suitable tank mates  include Characin species like the Cardinal Tetra, Neon Tetra, Rummynose Tetra, Glowlight Tetra, Emperor Tetra or Congo Tetra. It should not be kept with Angelfishes and Corydoras Catfish. Discus fish is very sensitive to water fluctuations and at least 25 % tank water should be changed every week to make the tank environment healthy.

Breeding Discus Fish

The blue discus is an egg layers and it can breed in captive condition. The female lays 200-400 eggs which attach to plants, driftwoods, rocks and ornamentations in the aquarium. The eggs are fertilized by the male after the eggs are all laid. Water conditions for breeding should be slightly acidic, soft and warm with a pH of about 6.0 – 6.5, hardness of about 10 – 150 dGH and the temperature should be between 82 – 88° F.  The parents guard the eggs.  Eggs hatch in about 2 days.  The parents should remain with the fry.  The fry feed on skin secretions from the parents for the first 10 days, after which the parents should be removed from the tank.  The fry should be fed with brine shrimp.

Sexing discus fish

It is hard to distinguish the sex. During breeding season, the males bear more pointed papillae while the female’s papilla is rounded. Males may be larger and some males have a more pointed dorsal fin and thicker lips.

Discus Fish for sale and where to buy

This fish is often considered as the most beautiful of all freshwater fish. It is called the King of the Cichlids by many hobbyists. It is available in pet store, breeders, especially dealers and online. It is moderate to moderately expensive. Prices vary depending on size and variety.  There are many online vendors that specifically sell Discus. See below online vendor and you can buy your favorite fish that I would recommend from.