Glowlight Rasbora
Glowlight Rasbora

Glowlight Rasbora - Trigonostigma hengeli

Glowlight Rasbora
Glowlight Rasbora - Picture by

Common name: Glowlight Rasbora, Hengel's Rasbora, Lamb Chop Rasbora, Glowing Rasbora, False Harlequin rasbora
Scientific name: Trigonostigma hengeli
Synonyms: Rasbora hengeli
Size: 4 cm / 1.5 inch
pH: 6.0- 7.5
Temperature: 72-79° F (22-26° C)
Hardness: 1 - 10 °N
Lifespan: 2-3 years

The Glowlight rasbora is a beautiful little fish. It is a shoaling species that should only be kept in groups of 8 fish or more. They are hardy and more forgiving than many other rasbora species, which makes it an ideal first rasbora if you want to start keeping these small gems. The species is also comparatively disease resistant. Unfortunately, the Glowlight rasbora is rather rare in the trade. It can however be found in well stocked fish stores from time to time. They are faster swimmers than many other rasboras and can be kept in community aquariums with other small and friendly species.

This species is one of three species that are often confused with each other and sold under the wrong names. This is not made any easier by the fact that the species share certain common names. The other two species are the harlequin Rasbora (Trigonostigma heteromorpha) and the Lambchop rasbora (Trigonostigma espei). This species and the lamb chop Rasbora are both sold as false harlequin Rasbora. It is possible to tell the species apart if you take a closer look at their colorations and patterns. The Harlequin Rasbora is higher (stalkier) than the other two species. It has a pink to bright red color. The black spot is located close to the triangle on the back of the body and the spot as a blue hue to it. The Harlequin Rasbora also has a larger triangle then the other two species. The Lambchop Rasbora has a bronze pink colour. The Glowlight Rasbora is butter coloured and has a faint orange line above its black spot. This line is not present in the Lambchop Rasbora.

The Glowlight rasbora originates from Borneo, Sumatra, and Indonesia. In their native range they can be found in slow moving streams. They are usually found in very large shoals. Most of the fish in the trade is wild caught but so far the species seems to be coping well with the harvesting and is not endangered

Aquarium & care

An aquarium of at least 20 gallon / 75L is to be preferred when housing a school of Glowlight rasbora. It is a hardy fish and it will do well in most aquariums as long as they are not kept with large or aggressive tank mates. Ideal tank decoration includes dense vegetation along the sides and the back of the aquarium while still leaving some open area in the middle for the fish to swim in. A dark bottom substrate helps intensify the coloration of the fish. They prefer if there are a couple of shaded areas among bogwood and plants. Keep some bottom dwelling fish in the aquarium to help clean up food that sinks to the bottom as Glowlight tetras very seldom swims to the bottom and food that sinks to the bottom might otherwise be left there to pollute the water.

Feeding Glowlight Rasbora

The Glowlight rasbora is easy to feed as it is an omnivore that will accept most types of food. They will readily devour flake food and flakes can make the base of their diet. They should however be offered a varied diet that includes vegetables as well as frozen and live food. This will keep your fish in better condition than a diet of just flake food and will make them more colourful.

Sexing Glowlight Rasbora

The Glowlight rasbora is very very hard to sex. The females can be a little rounder but it is hard to tell and not a reliable way of sexing this species.

Breeding Glowlight Rasbora

The Glowlight rasbora is very hard to breed and has only been bred successfully a few times in aquariums. It can be bred in a similar fashion to other Trigonostigma species. Breeding this species require soft acidic water. The aquarium should be decorated with a mesh or marbles on the bottom that protects the eggs from being eaten by the parents. Include both wide and fine leafed plants in the aquarium. Introduce well conditioned fish to the breeding tank.  (You condition the fish by feeding them a lot of live food.)

The parents should be removed from the tank as soon as the spawning is finished. If your fish don’t want to spawn you can try triggering a spawning by dimming the light. The eggs and fry are very small and can be hard to see.

Feed your Glowlight rasbora fry infusorians to begin with. When they are about 10 days old they are usually large enough to start eating newly hatched brine shrimp. After another week or two they can be expected to have reached a size where they accept crushed flake food. If your fry have survived this long they are usually easy to raise from this point on.