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

Trichopsis pumila, the sparkling or pygmy gourami, is the smallest of the commonly kept gouramis, a tiny labyrinth fish from the lower Mekong basin across Cambodia, Laos, Thailand, and southern Vietnam, plus peninsular Thailand, living in slow rivers, rice paddies, ditches, and weedy swamps with thick surface plants and low oxygen. Arnold described it in 1936. It is the smallest of the three Trichopsis species, alongside T. vittata and T. schalleri. As an anabantoid it breathes air at the surface through a labyrinth organ, which lets it cope with the still, oxygen-poor water it favours. Its two signature traits are colour and sound: iridescent cells scatter red, blue, and green over the body and fins so the fish seems to sparkle under good light, often with bright blue eyes, and males produce a clearly audible croaking or clicking using specialised pectoral muscles, used in courtship and in squabbles between males. It grows to about 4 cm. IUCN lists it as Least Concern, and tank-bred fish are available alongside wild-caught.

Breeding

A bubble-nest builder, like other anabantoids, on a miniature scale. The male blows a small raft of bubbles under a floating leaf or in a corner and croaks at the female to court her; when she is ready the pair embraces beneath the nest and she releases a small batch of eggs, a dozen or so at a time, which the male gathers and tucks into the bubbles. Several embraces build up to a modest spawn, after which the male guards the nest and the female is best removed. The eggs hatch in about a day to a day and a half, and the fry hang in the nest a couple of days before swimming free. The fry are minute and need infusoria or paramecium before baby brine shrimp, and that tiny first-food requirement is the main hurdle in raising them.

Common problems

It is hardy once settled but easily knocked back by transport and acclimation, so a quiet few days, and moving it in a cup rather than a net, help a new fish recover. Coming from still water, it dislikes strong current, so a sponge filter or a baffled outflow suits it better than a powerhead. It can jump, so a lid is sensible. The labyrinth organ lets it tolerate low oxygen, but it still needs clean, stable water, and bacterial problems like fin rot follow when quality slips. A useful tell is the croaking itself: a confident male croaks, so a male that has gone quiet, or one that is pale and hiding, is usually signalling stress. Keep it away from dwarf gouramis, which can carry iridovirus, and from bettas, since both compete for the surface.

Bioload

Further reading

• Biotope aquariums: matching fish to their natural habitat