Pearl gourami

A tank with a volume of 120 litres (30 gallons) or over is generally recommended for a pair of pearl gouramis, although anything above that volume is greatly recommended, since these fish may show signs of stress, abnormal aggression, and illness when confined.[6] Preferred tank temperatures are 22–28°C (72–82F).[3] Tanks with surfaces exposed to fresh, humid air are needed so that the pearl gourami's labyrinth organ can function correctly. As with any tropical aquarium, adequate filtration, lighting, substrate and decorations, plants, and other parts of proper care are required. This fish may be somewhat timid or shy, and should not be kept with fish that are too boisterous or aggressive.[6] In fact, in the first several days or weeks, these fish typically show extreme shyness and timidness, spending a great deal of time hiding, regardless of tank-mates or water properties. If in proper conditions, however, they will outgrow this and become more gregarious, becoming social fish. Although somewhat hardy, pearl gouramis can be vulnerable to disease, so clean water is a must. Many gouramis display bolder behavior when the tank is furnished with plants, decorations, and ornaments which provide safe refuges for the fish in times of stress.

The pearl gourami is a bubble nest builder that uses plants to help bind together the bubbles. The water level should be reduced to 20 cm (8 in) during spawning ,[7] and the temperature should be approximately 28 °C (82 °F) and with a pH of around 7. After spawning both adults cannot be kept together. The eggs hatch after two days and the fry become free swimming three days later (Ter Morshuizen 2007). When they commence with swimming freely the fry can be fed infusoria and brine shrimp, and a week later finely ground flakes. Freeze-dried tablets may also be fed to older fry. The temperature needs to be high (about 84 °F) and with little or no water movement. Since they are air breathers, filtration is not necessary.

The pearl gourami has a very unusual and beautiful mating dance. The male builds a nest of tiny, durable bubbles. The female takes a position under the nest and the male curves his body tightly around her, from underneath. Her body quivers while she expels a few eggs. Next he releases her and picks up the eggs in his mouth as they are sinking, then he spits them into the bubble nest. This sequence is repeated several times, until the female has laid all of her eggs.

The fry are tiny at hatching (.2 mm or smaller). The male cares for the fry, taking them into his mouth and spitting them back into the nest if they fall out. Some tend to grow faster than others, and will exhibit fratricide, eating their smaller siblings.