Licorice gourami

Overview

The licorice gourami (Parosphromenus deissneri and its many close relatives) is a tiny, secretive blackwater labyrinth fish from the peat swamps of Southeast Asia. At barely 3.5 cm, a courting male is astonishing — deep bands of black, red and iridescent blue that flare in a shadowy tank. It is not a fish for a first aquarium: it is one of the great specialist nano species, kept by hobbyists who take pride in recreating soft, acidic blackwater conditions.

Tank & water

A pair thrives in a mature, dimly lit 25-litre (6-gallon) species tank, richly furnished with botanicals.

• Water: extremely soft and acidic, pH 4.0–6.0, is the key requirement; most keepers use RO or rainwater stained with tannins from leaf litter, alder cones and peat. See how do I soften aquarium water.
• Temperature: 22–26 °C from a small heater; they dislike heat.
• Gentle flow, low light: a soft sponge filter and dim lighting match their shady home. Leaf litter provides caves for spawning.
• A lid: they breathe surface air and can jump.

Feeding

Licorice gouramis are micropredators that generally refuse dry food. Offer small live and frozen fare — baby brine shrimp, daphnia, cyclops, microworm and grindal worm. Feed little and often, and make sure the food actually reaches these slow, shy feeders rather than being snatched by tankmates. See how often should I feed my fish.

Behaviour & tankmates

Keep them as a pair or small group in a species-only, blackwater setup — they are far too shy and slow to compete in a community. Males defend small cave territories and court females with mesmerising fin displays. Add nothing boisterous; even active nano fish will stress them out of the open.

Give the licorice gourami a quiet, soft, dark, botanical-rich tank and live food, and you get one of the most rewarding projects in the nano hobby — see our best nano aquarium picks for suitable homes.