Samurai gourami
Sphaerichthys vaillanti
advanced careOverview
The samurai gourami (Sphaerichthys vaillanti) is a striking, specialist labyrinth fish from the blackwater streams of Borneo — a close relative of the chocolate gouramis. Its coppery-brown body flushes with iridescent green and red, and a breeding female develops bold cross-bands that inspired the “samurai” name. It is a beautiful, unusual maternal mouthbrooder, but it is a fish for keepers who can commit to soft, warm blackwater and live foods.
Tank & water
A small group needs a mature, quiet 60-litre (15-gallon) tank or larger, heavily furnished and dimly lit.
- Water: very soft and acidic, pH 4.0–6.0, stained with tannins from leaf litter, botanicals and peat. Most keepers use RO or rainwater blends — see how do I soften aquarium water.
- Temperature: 24–28 °C from a steady heater; stability is critical.
- Gentle flow, low light: a soft sponge filter and shady planting suit their timid nature.
- A lid: they are surface-air breathers and can jump.
Feeding
Samurai gouramis are shy micropredators that rarely take dry food. Feed small live and frozen fare — baby brine shrimp, daphnia, cyclops, microworm and finely chopped bloodworm. They feed slowly and deliberately, so avoid greedy tankmates that will beat them to every meal, and offer small amounts several times a day.
Behaviour & tankmates
These are peaceful, retiring fish best kept as a group of six or more, ideally in a species-only blackwater aquarium so their subtle interactions and mouthbrooding can be seen. If you add tankmates, restrict them to the smallest, calmest soft-water nanos and provide dense planting and leaf litter for cover.
Frequent small water changes with matched soft, warm water keep conditions stable without shocking them, and a tight-fitting lid guards against jumps and lets them breathe warm, humid surface air. Patience through the settling-in weeks is the single biggest factor in success with this species.
Give the samurai gourami warm, soft, dark, stable water and a live-food diet, and you get one of the most rewarding — and demanding — blackwater fish in the hobby. See our best nano aquarium picks for suitable, easily managed homes.
Samurai gourami — frequently asked questions
Why is the samurai gourami so hard to keep?
Like the chocolate gouramis it is related to, it demands very soft, acidic, warm blackwater and is highly sensitive to poor water quality and swings. It also needs live and frozen foods and quiet tankmates. Get the water and diet right and it is manageable, but it is unforgiving of the shortcuts a beginner might take.
Is the samurai gourami a mouthbrooder?
Yes — Sphaerichthys vaillanti is a maternal mouthbrooder, unusual among gouramis, with the female carrying the eggs and fry. The breeding female develops striking cross-banded 'samurai' markings that give the fish its common name.
Can I keep samurai gouramis with other fish?
Only with the calmest soft-water nano species, and many keepers prefer a species-only tank. They are timid, slow feeders that are easily out-competed and stressed by active fish, so quiet company and dense cover are essential.
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