Two Spot Catfish (Mystus bimaculatus) care guide

Group
Freshwater fish
Other names
Two Spot Catfish, Two-spot Mystus
Family
Bagridae (bagrid catfishes)
Origin
Asia: endemic to Sumatra, Indonesia, in blackwater peat swamps of the Sengi Si Russu and Kwantang river systems.
Water
freshwater
Maximum size
6.7 cm
Temperature
23–32°C
pH
4–5.5
Hardness
Very soft; tolerates medium-hard, near-neutral water
Minimum tank
80 litres
Care level
intermediate
Temperament
peaceful

Care

A small, red-brown bagrid from Sumatran peat swamps, growing to about 6.7 cm standard length. It is one of the few Mystus small enough for a modest community tank. The 80-litre minimum here is our estimate for a small group. Tank: a blackwater biotope suits it best: a thin layer of peat or fine sand, plenty of driftwood forming caves, dense planting and floating plants to dim the light. PlanetCatfish stresses that caves are the most important feature. Keep a small group so that individuals can spread out. Water: naturally very soft and acidic (pH 4-5.5) and warm, but captive-bred fish adapt to medium-hard water near neutral pH. Identification: a dark spot on the shoulder and another on the caudal peduncle, each with a lighter surround, give the common name. Males have a small genital papilla in front of the anal fin that looks like a loose fin ray; ripe females are noticeably fuller. Status: listed as Near Threatened by the IUCN (2019) because of peat-swamp loss. Most fish in the trade are commercially bred in East Asia and Russia, which is a better choice than wild-caught stock. Sources: PlanetCatfish (planetcatfish.com/common/species.php?speciesid=332); FishBase (fishbase.se/summary/Mystus-bimaculatus.html). Checked October 2026.

Diet

Carnivorous leaning. PlanetCatfish suggests dry foods (small sinking pellets, granules, tablets) on four or five days a week and frozen or live foods such as bloodworm, brine shrimp and daphnia two or three times a week; reverse the ratio when conditioning for breeding.

Breeding

In the trade it has so far only been bred with hormone injections. Eggs are scattered over a peat substrate. Attempts at natural spawning use a blackwater set-up with heavy feeding of live and frozen food and large daily changes with distilled or very soft, slightly cooler water once the females are gravid.

Compatibility and tank mates

Peaceful when well fed and rarely even bothers fry, according to PlanetCatfish. Good companions are other soft-water fish such as pearl gouramis, glass catfish and blackwater rasboras. Avoid very small shrimp and boisterous fish that outcompete it at feeding time.

Last updated 5 October 2026. Community-edited care guide on Aquatic-Auctions.

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