Dwarf gourami

Quick facts

Adult size

8 cm

Lifespan

can live up to 4 years; dwarf gourami iridovirus shortens lifespan in chain-store stock; quality breeders produce fish that live 3-5 years

Tank zone

top

Temperament

peaceful

Difficulty

intermediate

Water parameters

Temperature

24–28°C

pH

6.0 to 7.5

Hardness

2 to 18 dGH

Tank requirements

Minimum volume

75 L

Minimum length

60 cm

Flow

low

Lighting

dim preferred

Substrate

any

Hiding spots

needed

Lid

required - jumper

Feeding

Diet: omnivore, feeds primarily at the top.

Omnivore that accepts flake, micro pellets, frozen bloodworm, daphnia, and brine shrimp. Not a picky eater. Small portions twice daily. Gouramis are surface-to-midwater feeders. Vary the diet between dry and frozen food. Males sometimes become picky after a water change or if stressed; this usually resolves within a day or two.

Compatibility

• Males are territorial with each other. Keep one male per tank unless the tank is large (200 L) with broken sightlines.
• Generally peaceful with community fish but can harass slow-moving tankmates or fish with similar body shapes.
• Good tankmates: tetras, rasboras, corydoras, kuhli loaches, bristlenose plecos. Avoid fin nippers.
• Males may build bubblenests at the surface and become defensive of the nest area, nudging away other surface-dwellers.
• The biggest compatibility issue is with the fish itself: commercially bred dwarf gouramis carry a high rate of dwarf gourami iridovirus (DGIV), which limits their lifespan regardless of care.

Habitat

Native to slow-moving, heavily vegetated waters in India, Bangladesh, and Pakistan. Males are bright red-orange with turquoise-blue vertical bars; females are plain silver-gray. Multiple color varieties exist through selective breeding: powder blue (all blue), flame (all red-orange), neon blue, and robin (mixed). One of the most popular tropical fish due to the male's striking color. The labyrinth organ allows them to breathe atmospheric air, which is why you'll see them visiting the surface. Wild populations live in rice paddies and shallow ditches, not open rivers. They prefer calm water with floating plants that provide cover and reduce light intensity.

Breeding

Bubblenest builder. The male constructs a raft of bubbles (often incorporating plant material) at the surface, usually in a corner or under a floating leaf. He courts the female with color displays and leads her under the nest. Spawning involves an embrace where the male wraps around the female; she releases eggs which the male catches and places in the bubblenest. Remove the female after spawning. The male guards the nest aggressively. Eggs hatch in 12-24 hours; fry become free-swimming 2-3 days later. First food is infusoria, then baby brine shrimp. Breeding is not difficult; the challenge is finding breeding stock that isn't carrying DGIV.

Common problems

Dwarf gourami iridovirus (DGIV) is the elephant in the room. An estimated 25-50% of commercially bred dwarf gouramis carry this virus, which causes lethargy, loss of color, abdominal swelling, and death over weeks to months. There is no treatment. DGIV is specific to Trichogaster lalius and does not affect other species, but it makes dwarf gouramis a risky purchase from mass-breeding facilities. Buying from local breeders or specialty importers reduces the risk. Beyond DGIV: bacterial infections, fin rot from poor water quality, and ich from transport stress. Males sometimes become overly aggressive when breeding, injuring the female; always have dense planting so the female can hide.

Bioload

Bioload coefficient: 2.2 (deeper-bodied than betta but slower; per-cm load similar to a small adult angelfish).

Bioload coefficients are calibrated against the neon tetra as the anchor (1.0). See the methodology page for the formula and how each value was derived.

Further reading

• Stocking ideas by tank size