Sparkling gourami

Water parameters

Tolerated range for this species. Aim for the middle of each band rather than the extremes.

Tank and habitat

Substrate: any.

Behavior

Plant interaction: plant safe.

Typically wild-caught; acclimate slowly.

Feeding

Small mouths require small food. Micro pellets, crushed flake, frozen baby brine shrimp, frozen daphnia, frozen cyclops, and live food (baby brine shrimp, microworms, daphnia, fruit flies) are the core diet. They hunt by stalking prey items and striking, a behavior clearly visible when feeding live food in a nano tank. Surface tension can trap food particles and sparkling gouramis will pick at items stuck to the surface film. Feed twice daily in small amounts. In community tanks they're not competitive feeders and need targeted feeding if housed with faster species.

Compatibility

• The smallest commonly available gourami at 3–4 cm. Peaceful toward other species but males spar with each other using an audible 'croaking' sound produced by specialized pectoral fin muscles. You can hear it from across the room in a quiet house.
• Good nano community fish with other calm, small species: ember tetras, chili rasboras, pygmy corys, and shrimp. Avoid anything boisterous that would stress them or large enough to eat them.
• Males are territorial toward each other in small tanks. In a 20-liter tank, one male is the maximum. In 60 L with dense planting, 2-3 males can coexist with enough sightline breaks.
• The croaking is the main attraction. Males croak during territorial displays and courtship. The sound is a rapid series of clicks, surprisingly loud for such a tiny fish. Most keepers hear it before they identify the source.

Origin and habitat

Native to mainland Southeast Asia, specifically the lower Mekong River basin in Cambodia, Laos, Thailand, and southern Vietnam. Also known as the pygmy gourami or dwarf croaking gourami. Described by J.P. Arnold in 1936. Found in slow rivers, rice paddies, ditches, small ponds, and swamps with dense floating plant cover; most commonly in standing (not necessarily stagnant) water with low oxygen levels. A labyrinth fish with an air-breathing organ that supplements its gills, allowing survival in oxygen-poor water. Produces a distinctive croaking or clicking sound using specialized pectoral muscles, used in courtship and territorial disputes; this is one of the species' most notable features. Iridescent chromatophores produce red, blue, and green colors on the body and fins that sparkle under adequate lighting, giving the species its common name. Eyes can appear bright blue. The smallest of the three recognized Trichopsis species, alongside T. vittata (croaking gourami) and T. schalleri. Grows to about 4 cm standard length. Males can be territorial with their own species but are otherwise peaceful and timid. Lifespan roughly 4-5 years. Tank-bred specimens available. IUCN Least Concern.

Breeding

Bubble nest builder. The male constructs a small nest of saliva-coated bubbles, usually under a floating leaf or in a corner near the surface. The nest is tiny compared to those built by larger gouramis. Courtship involves the male croaking at the female and displaying with spread fins. When the female is receptive, the pair embraces beneath the nest and the female releases 10-40 eggs per embrace. Multiple embraces produce 50-150 eggs total. The male catches sinking eggs and places them in the nest. After spawning, the male guards the nest; remove the female to prevent harassment. Eggs hatch in 24-36 hours. Fry hang from the nest for 2-3 days, then become free-swimming. The male should be removed at this point. Fry are extremely tiny and need infusoria or paramecium for the first week before graduating to baby brine shrimp nauplii. The tiny size of the fry is the main breeding challenge; they starve easily if the right micro-food isn't available. In a mature, densely planted tank with abundant microorganism populations, some fry survive without dedicated feeding.

Common problems

The species is hardy once established but sensitive during acclimation and transport. New arrivals that are pale and hiding need a few days of quiet to settle in. Avoid netting if possible; use a cup. Overly strong current from filters is a common setup mistake; sparkling gouramis come from still water and struggle in tanks with powerheads or strong outflow. Use a sponge filter or baffle the output. Jumping happens occasionally; a lid is advisable. The labyrinth organ means they tolerate low oxygen, but they still need clean water with stable parameters. Bacterial infections (fin rot) appear when water quality slips. The croaking behavior is usually a sign of health and confidence; a silent sparkling gourami is either female or stressed. Males that stop croaking in a tank where they previously did are signaling a problem.

Bioload

Further reading

• How to cycle a fish tank
• Stocking ideas by tank size