False Harlequin Rasbora, Lambchop Rasbora Trigonostigma espei

Lambchop Rasbora. Picture by JJphoto.dk

Common name: Lambchop Rasbora, Espei Rasbora, Slim Harlequin Rasbora, False Harlequin Rasbora, Espe’s Rasbora
Scientific name: Trigonostigma espei
Synonyms: Rasbora espei, Rasbora heteromorpha espei
Size: 4-5 cm / 1.8-2 inches
pH: 5-7
Temperature: 73 – 82 °F (23 – 28 °C)
Lifespan:  3-5 years


The Lambchop rasbora or False harlequin rasbora is a small very friendly schooling fish perfect for any planted community aquarium with other friendly species. They roam the aquarium in loose schools without bothering any of the other aquarium inhabitants. It is a good companion to keep with small shrimp species. The Lambchop rasbora should not be kept with fast swimming or aggressive fish as this can cause them to become very timid.

The Lambchop rasbora originates from south East Asia where it is mainly found in Cambodia and Thailand.

This species is one of three species often confused with each other and sold under the wrong names. This situation is made even more confusing by the fact that the species share certain common names. The other two species are the Harlequin Rasbora (Trigonostigma heteromorpha) and the Glowlight Rasbora (Trigonostigma hengeli). Glowlight Rasbora and Lambchop Rasbora are both sold as False harlequin rasbora. It is possible to tell the species apart if you look closely. The Harlequin rasbora is higher (stalkier) than the other two species. It has a pink to bright red colour. 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.

Aquarium & Care

The Lambchop rasbora is very hardy compared to other rasbora species and can be kept without much pampering as long as their basic requirements are met. Below you will find information on some conditions that you should try to meet to make you Lambchop rasboras feel more at home and make them show their best side.

The aquarium should where you keep Lambchop rasboras should not be smaller then 10 gallon (50 L). Lambchop rasbora is best kept in a densely planted aquarium that contains both fine leafed and broad leafed plants. Dark substrate is to be preferred as this make the fish show a more vibrant red color, but any substrate will do. Make sure there are shaded areas in the aquarium where the fish can seek refuge from the light when resting. Roots and bogwood are recommended as it helps maintain suitable water conditions for this species but are not necessary if you manually maintain soft acidic water conditions.

Lambchop rasboras should always be kept in schools and will do very poorly if kept alone or in groups of less than 6-10 individuals. The more specimens the better, provided of course that your aquarium is large enough to house them.

It is important to cover the aquarium well as Lambchop rasboras are excellent jumpers and tend to jump to get away from perceived dangers or simply because they are excited about something. If there is a hole for them to jump out of the tank through, you can be sure they will jump through it sooner or later.

Feeding Lambchop Rasbora

The Lambchop rasbora is easy to feed as they are omnivores and will accept most food types. They do not but large demands on the owner and the diet can be based around a high quality flake food. They should be offered a varied diet that contain not live food and vegetable matter such as blanched lettuce. They will accept all live food that is small enough to be eaten. A good varied diet is required for this fish to breed.

Sexing Lambchop Rasbora

There is no sure way to sex Lambchop Rasbora based on external characteristics. It canhowever be said that males often are more brightly colored and that females often have a fuller rounder bodies. This is however by no mean certain indicators that a fish belongs to a certain sex.  If you want to breed them you will have to use a school as broad stock to make sure that both sexes are present.

Breeding Lambchop Rasbora

The Lambchop or False harlequin rasbora is usually rather hard to breed. It requires soft to very soft acidic water to breed. A suitable breeding aquarium can be setup by covering the bottom of a tank with two layers of marbles and then adding a couple of plants to the tank. They use broad leafed plants to deposit their eggs. The adult fish should be removed from the tank once spawning is completed to protect the egg and fry.

You will need to condition you Lambchop rasboras by feeding them live food a couple of weeks before you try to breed them. Dimming the light can help trigger spawning if needed.

Lambchop Rasbora eggs and fry are very small and the fry can be hard to see with the naked eye. The fry need to be fed very small food such as infusorians and vinegar eels. After a while they will be large enough to accept crushed flake food and from this point on the fry are easy to raise.