Pygmy gourami

The sparkling gourami is a true dwarf among labyrinth fish, reaching just 35–40 mm, and lives up to its common name with a constellation of iridescent blue-green and red spots scattered across its body and fins. When the light catches them right, these tiny spots sparkle brilliantly against a warm brown or olive background. Native to the sluggish lowland waters of Southeast Asia — including the lower Mekong basin in Laos, Vietnam, Cambodia, Thailand, and the Malay Peninsula — this species is found in still to slow-moving habitats such as swamp forests, peat swamps, floodplains, paddy fields, and roadside ditches. Like all members of the family Osphronemidae, it possesses a labyrinth organ that allows it to breathe atmospheric air.

Sparkling gouramis are best kept in a well-planted, shady aquarium that mimics their blackwater natural habitat. The tank should include plenty of floating plants or tropical lilies to diffuse the light, driftwood, leaf litter, and a dark substrate. Strong water movement must be avoided — an air-powered sponge filter set to a gentle turnover is adequate. A 40-litre tank can house a small pair or trio, with a footprint of at least 45 × 30 cm. Water temperature should be 22–28°C with a pH of 5.0–7.5 and hardness of 18–215 ppm. The aquarium must be well-covered and not filled to the top, as they require access to the warm, humid air layer above the water and are excellent jumpers.

These are exceptionally peaceful, timid fish that do best in a species-only tank or alongside other tiny, non-aggressive inhabitants such as dwarf rasboras, small shrimp, or pygmy cories. They should never be housed with large or boisterous species. Males produce an audible croaking or grunting sound during courtship — one of the few fish that can vocalise audibly through air. The diet should consist of small live and frozen foods: daphnia, brine shrimp, micro-worms, and finely crushed flake. They are bubble-nest builders: the male builds a nest under a broad leaf, courts the female, and tends the eggs and fry with great care. The fry are tiny and require infusoria as a first food. With stable conditions, sparkling gouramis can live three to four years, bringing subtle beauty and fascinating behaviour to the nano aquarium.