Mochokidae

Domino Synodontis

Synodontis notatus

Synodontis notatus, the Domino Synodontis, belongs to the family Mochokidae. Despite the name suggesting a single spot, the body can have up to 6 round marks. This is an easy fish to keep and gets along with most other aquarium inhabitants, except very small ones that it may swallow; it shows aggression toward its own kind. For this reason, keep only one in the home tank.

Tank
from 150 L (40 gal)
Temperature
22 – 25 °C (72 – 77 °F)
Size in aquarium
27 cm (11 in)
Acidity
pH 6.5–7.5

Dangerous to small fish

Natural rangeRange on the map
  • Congo River Basin
  • Democratic Republic of the Congo
  • Republic of the Congo

Tank conditions

Plan the tank stocking
Temperature
22 – 25 °C (72 – 77 °F)
Water pH
Neutral (6.5) – Neutral (7.5)
Water dH
Medium hardness (8) – Very hard (18)
Water salinity
no salt (freshwater)
Size in aquarium
27 cm (11 in)
Lifespan
10 years
Temperament
Semi-peaceful dangerous to smaller ones
Toward small fish
a risk to small fish
Required aquarium volume
from 150 L (40 gal)
Lighting
dimmed or moderate
Substrate
soft peat-based
Water flow
weak or moderate
Swimming level
lower level
Feeding
Sinking (any)
Keeping
Solitary
Jumping
low
  • Lifespan. A lifespan to expect under good care, not a measured value: it depends heavily on tank volume, water quality and diet — and for selectively bred forms, on their origin as well.
  • Toward small fish. Based on the Predators category in the catalog or the temperament in the species parameters. “A risk to small fish” means the species is not a predator by habit, yet will swallow any fish that fits in its mouth.
  • Required aquarium volume. This is a husbandry recommendation, not a measured value: the volume depends on the keeping mode (solitary), footprint, decor and tank mates.

Care and keeping

Description

Adults reach about 27 cm. The fish is usually grey with large, rounded marks. Their number varies, but usually no more than three — this trait gave the species its name, Domino Synodontis. Males and females are hard to tell apart, as sexual dimorphism is weakly expressed.

Habitat

This fish is widespread in the Congo River basin, covering parts of the Democratic Republic of the Congo and the Republic of the Congo. Domino Synodontis inhabits various biotopes but favours areas with weak water flow and backwater zones rich in natural shelters.

Behavior and Compatibility

This fish is semi-peaceful and gets along well with many other aquarium inhabitants, except very small ones that may accidentally become food for this large catfish. This is not aggression but the indiscriminate feeding behaviour typical of most catfishes. Intraspecific relations are complex. Adults are territorial and may engage in serious conflict if the tank is too small or lacks enough hiding places. Choose tank mates that are too large to fit in its mouth: tiny fish are seen as food.

Care and Maintenance

One fish needs at least 150 litres. Use soft sandy substrate and add driftwood and roots to create comfortable shelters. Rock fragments are welcome too. Aquatic plants are not essential but useful — floating plants at the surface give extra shade. Domino Synodontis prefers dimmed light, though it will manage under moderate lighting in a community tank. Its wide native range means it adapts to various water chemistries, so preparing water is not difficult. Still, regular gravel cleaning and partial water changes remain important.

Diet

This fish is omnivorous and unfussy. It eats dry food, frozen, live, and plant matter readily. Peas, cucumber, and spinach can be added to its diet. Varied feeding keeps the fish in good condition and reduces digestive problems. Quality matters in dry foods, as poor-quality products can harm the fish.

Breeding and Reproduction

Breeding in home aquariums is rare, so reliable data on spawning in captivity is scarce. Commercial fish farms breed this species successfully, so most animals sold are now captive-bred rather than wild-caught.

Diseases

Poor conditions and low-quality food cause most disease. If you notice signs of illness, check water parameters immediately and ensure no dangerous substances are present (ammonia, nitrites, nitrates, etc.). Correct the parameters, then begin treatment.

How to choose

When buying, choose active fish with clean skin and no visible damage, ulcers, or white spots. Check the barbels: they should be intact, without erosion, which shows the fish was kept properly in the shop. Avoid specimens with a sunken belly or unnatural bloating. Note that sharp spines on the pectoral and dorsal fins tangle easily in nets, so handle the fish with care to avoid injury and damage to the net. In shops, catfish often hide, so ask the seller to show them feeding to check appetite and confirm they are not overly shy.

Compatibility

There are no pair reviews for this species yet — check tankmates in the matcher.

All tankmates

Plants and this fish

Matching water does not mean the plant will stay intact.

Frequently asked questions

The essentials: size, tank volume, water parameters and care

How big does Domino Synodontis get?

An adult reaches 27 cm in length. Plan the tank around the maximum size: the fish quickly outgrows a cramped setup.

What size aquarium does Domino Synodontis need?

The recommended volume is 150 L. A smaller tank speeds up nitrate build-up and raises stress levels.

What water parameters does Domino Synodontis need?

Temperature 22–25 °C, pH 6.5–7.5, hardness 8–18 dGH. Stability matters more than exact values: sudden swings are harder on the fish than a small deviation from the ideal.

How long does Domino Synodontis live?

Around 10 years when kept properly. Lifespan depends directly on tank volume, water quality and a varied diet.

Is Domino Synodontis aggressive?

Temperament: semi-peaceful (dangerous to smaller ones). Not a predatory species, but small fish that fit in its mouth will eventually be eaten.

How many Domino Synodontis should be kept together?

Recommended setup: solitary. Ignoring this is a common cause of stress and disease.

What does Domino Synodontis eat?

Diet type: sinking (any). Feed small portions that are finished within a couple of minutes — overfeeding does more harm than underfeeding.

What is the scientific name of Domino Synodontis?

The scientific name of the species is Synodontis notatus, family Mochokidae. It also appears in the literature as: Synodontis maculatus.

Similar fishes

Matched by family, categories and overlapping keeping conditions

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Other scientific names and conservation status

Other scientific names
Synodontis maculatus
Categories
Catfish
Conservation status
Least concernLC