Six-Banded Distichodus (Distichodus sexfasciatus)

Choose the Six-Banded Distichodus only if you can house a giant

The Six-Banded Distichodus (Distichodus sexfasciatus) is a large African characin from the Congo basin. Young fish are some of the most eye-catching in any shop: an orange-gold body crossed by six bold black bands, with bright red fins. That juvenile look is what most people buy, but this is a fish that becomes a heavy, plant-eating adult of 40 cm or more, and it should be bought only by someone with an aquarium, or a plan for one, that can hold it for life.

FishBase records it across the Congo River basin, from the lower Congo up to the upper Lualaba, and in the Lake Tanganyika basin. In the wild it swims in shoals in the lower water layers of rivers and inshore areas of lakes, eating worms, crustaceans, insects and plant matter. It is listed as Least Concern on the IUCN Red List (assessed 2009), and FishBase notes that it is taken by commercial fisheries as well as for the aquarium trade.

Seriously Fish calls it the most common Distichodus in the hobby and warns that it is often sold as a community fish, which is wrong given its size and temperament. Its advice is plain: do not buy one unless you can house it for life. We agree, and this page sets out exactly what that means, so you can decide with full information.

Check the names on the label

Browse our African tetras and characins for its relatives, our wider range of tetras and characins, and our centrepiece fish for other single-specimen fish for large aquariums.

Know what one purchase supplies

One purchase quantity supplies one live Six-Banded Distichodus. The only option is "Standard": the fish is not graded into sizes, so it is sent at the size available on the day, which will be a juvenile far smaller than the adult. Seriously Fish records no known external differences between males and females, so sex cannot be chosen.

The photographs show the juvenile colour form. Each fish varies a little in the width of its bands and the depth of its red, and colour is paler for a few days after travel.

Expect the colours to change with age

Seriously Fish notes that juveniles are orange and black with bright red fins, but much of this colour and pattern fades as the fish grows, and that adults are rarely seen for sale. The fish you keep for years will be larger, deeper-bodied and more muted than the one in the photographs. If the bright juvenile colours are the main attraction, a smaller species will suit you better; the Silver Distichodus, which Seriously Fish gives as 200 mm standard length and which develops red fins as it matures, is the more manageable relative.

Plan for a 40 cm fish and a 240 cm aquarium

FishBase gives a maximum of 76 cm standard length, measured without the tail. Seriously Fish gives 75 cm and adds that fish in aquariums are rarely over 40 cm, which is still a very large, deep-bodied fish. The tank has to be planned around that adult, not around the juvenile you buy. Our tank volume calculator turns dimensions into litres, and our stocking calculator helps you judge what else the tank can hold.

Plan the growth path before you buy

OATA's care sheet for very large "tank buster" fish advises buying for the adult size rather than the juvenile size, and reminds owners that these fish can live a long time. If you start a juvenile in a smaller, mature aquarium, have the final aquarium or indoor pond planned, budgeted and ready to set up long before the fish outgrows the first tank. OATA is also clear that aquarium fish must never be released into the wild; if your circumstances change, rehome it to an experienced keeper or a public aquarium.

Furnish the tank for a plant-eater

Seriously Fish says the Six-Banded Distichodus eats most greenery and is a poor choice for a planted aquarium. Build the layout from smooth rocks and large pieces of driftwood over sand or gravel, and leave a long, open swimming area along the front. If you want some green, Anubias and Bolbitis are the plants Seriously Fish suggests, because most fish leave them alone; attach them to wood or rock, and accept that a large distichodus may still damage them. Browse our tough aquarium plants for these epiphytes.

Some water movement is appreciated, which suits the powerful filtration a fish of this size needs anyway. Keep the décor stable: OATA advises securing décor in tanks of large fish so that it cannot be knocked over.

Secure the lid and protect the equipment

Seriously Fish describes this species as an excellent jumper and calls for a tight, heavy cover. OATA adds that large fish often jump, especially when newly introduced, and recommends a fish-proof lid and protected heaters. Use heater guards or heaters placed in the filter line, close every gap around pipes and cables, and keep the lid weighted or clipped.

Match the water before it arrives

FishBase and Seriously Fish give the same ranges for this species, and OATA sets the limits for waste products for all large fish.

Work with UK tap water

Tap water varies widely across the UK in hardness and mineral content, so test yours rather than assume. Treat every litre with a dechlorinator or conditioner, test pH and general hardness, and enter the numbers into our water matcher. Medium-hard water within the ranges above is easy to hold steady in a large volume; if yours is far outside, our water chemistry guide explains how to adjust it gradually. In an aquarium of more than a thousand litres, plan how you will treat and temperature-match large volumes of new water every week.

Filter heavily and change water every week

A large, plant-eating fish produces a lot of waste. Seriously Fish's turnover figure of four to five times the tank volume per hour means several large external filters or a sump on a tank of this size. The aquarium must be fully cycled, with ammonia and nitrite at zero, before the fish arrives. Our aquarium filtration guide explains how to size and maintain filtration.

Keep a weekly routine

• Every week: test ammonia, nitrite, nitrate, pH and hardness, as OATA recommends.
• Every week: change about 25% of the water, treating the new water with conditioner and matching its temperature.
• After meals: remove uneaten vegetables within a few hours, before they foul the water.
• When the filters slow: rinse the media in water removed during the change, never under the tap, so the beneficial bacteria survive.
• Every month: check heater guards, lid clips and pipework, because a strong fish can dislodge equipment.

Feed the Six-Banded Distichodus plenty of greens

Seriously Fish describes the species as omnivorous but stresses that it needs a good proportion of vegetable matter, and FishBase lists plant matter alongside worms, crustaceans and insects in its wild diet. Build every week's feeding around plant foods, with meaty foods as the smaller part.

Measure each meal

OATA advises feeding large fish once a day, only as much as they eat within a few minutes. Offer the portion, watch it go, and lift out what remains. A plant-eater that is underfed will turn to anything green in the tank, so a regular supply of vegetables also protects the décor. The fish should look well rounded but never swollen.

Settle it in during the first week

Read our delivery and live arrival information before ordering, and have the aquarium running, matured and tested before the fish arrives. Our guide on how to acclimatise new fish covers the method in detail; OATA's steps are below.

Acclimatise step by step

1. Switch off the aquarium lights and lift the bag out of its wrappings without exposing it to bright light.
2. Float the bag for about 10 minutes so the temperatures equalise.
3. Over up to 20 minutes, add small amounts of aquarium water to the bag.
4. Net the fish into the aquarium with as little bag water as possible, and close the lid straight away, because newly introduced large fish often jump.
5. Leave the lights off for the rest of the day and offer the first small meal the next day.

OATA advises monitoring water quality closely during the first week. Expect the fish to stay near cover at first and to colour up as it settles.

Pick large, robust tank mates

Seriously Fish describes the Six-Banded Distichodus as somewhat unpredictable. Some fish remain peaceful with similarly sized species, while others become very spiteful as they mature. Juveniles shoal peacefully, but they grow increasingly aggressive towards each other, and Seriously Fish says adults need a very large aquarium to be kept as a group. OATA's general advice for large fish is to avoid housing them with much smaller species.

Keep one fish unless the tank is huge

For most home aquariums, one Six-Banded Distichodus is the realistic number. A group is possible only in a very large system with plenty of space to spread out. Check every combination for adult sizes, not shop sizes, before you buy.

Watch for these health signs

OATA's checklist for large fish is a good daily routine. Look, especially at feeding time, for changes in:

• Swimming: hanging at the surface, sitting on the bottom or erratic swimming.
• Colour: sudden darkening or paling that is not the normal slow fading with age.
• Behaviour: more aggression, or hiding much more than normal.
• Breathing: gill covers moving faster or slower than usual.
• Appearance: white spots, fluffy growths, split fins or damage from jumping.
• Condition and feeding: weight loss, or no interest in food it normally takes.

If anything changes, test the water first, then contact us for advice. Damage to the snout or fins can come from jumping against the lid or from sharp décor, which is one more reason to use smooth rocks and wood.

Breeding notes

Seriously Fish knows of no captive breeding of this species, and there are no recorded external differences between males and females. In the wild, FishBase describes it swimming in shoals in the lower water layers of rivers and inshore lake areas. Home breeding is not a realistic goal for a fish of this size.

Six-Banded Distichodus buyer questions

How big does a Six-Banded Distichodus get?

Very big. FishBase records 76 cm standard length in the wild, and Seriously Fish gives 75 cm, adding that aquarium fish rarely exceed 40 cm. Plan for a heavy-bodied fish of at least 40 cm, not the small juvenile that arrives.

What size tank does it need?

Seriously Fish calls 240 × 90 × 60 cm, about 1,300 litres, the bare minimum for an adult. OATA notes that tank-buster fish often need more than 500 litres and that an indoor heated pond is an alternative. Buy for the adult size.

Will it eat my aquarium plants?

Yes. Seriously Fish says it eats most greenery and is a poor choice for a planted tank. Tough Anubias and Bolbitis are the only plants worth trying, and even those may be damaged.

Is the Six-Banded Distichodus a community fish?

No, despite often being sold as one. Seriously Fish describes it as unpredictable: some fish stay peaceful with similar-sized species, while others become very spiteful as they mature. Keep it only with large, robust fish.

What should I feed it?

A diet rich in plant matter: spirulina flakes or granules, herbivore pellets, blanched spinach and shelled peas, with earthworm, prawn and mussel for protein. Feed once a day, only what it eats within a few minutes.

Why has my distichodus lost its colour?

That is normal growth. Seriously Fish notes that juveniles are orange and black with bright red fins, but much of this colour and pattern fades as the fish grows. Sudden fading in a young fish, with other changes, is worth checking.

Can I keep several together?

Juveniles shoal peacefully, but Seriously Fish says they grow increasingly aggressive towards each other, and adults need a very large aquarium to be kept as a group. Most home aquariums suit one fish.

Has it been bred in aquariums?

Seriously Fish knows of no captive breeding, and there are no known external differences between males and females. In the wild, FishBase says it swims in shoals in the lower water layers of rivers.

References

• Seriously Fish: Distichodus sexfasciatus (Six-banded Distichodus)
• FishBase: Distichodus sexfasciatus Boulenger, 1897
• Seriously Fish: Distichodus affinis (Silver Distichodus)
• OATA: How to look after very large fish (tank busters)