Edit Trigonostigma espei

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Name

Scientific name

Trigonostigma espei

Described by

Authority Meinken, Year 1967

Family

Cyprinidae

Summary

The lambchop rasbora, Trigonostigma espei, is a small cyprinid from southwestern and southeastern Thailand, reaching into southwestern Camb…

Size and aquarium

Maximum size

30mm, standard length

Tank size

Minimum length 60 cm, Minimum depth 30 cm

Water

Temperature and pH

Temperature 23–28°C, pH 5.5–7.5

Hardness

1–10dGH

Conductivity

Not recorded

Behaviour

Temperament

Peaceful

Community suitability

Community-safe

Where it lives

Countries

Thailand

Supporting text

Etymology

Not written yet

Distribution

There appear to be two main populations of this species, one in the far southwest of Thailand and the other in the southeast of the country around the border w…

Habitat

Varies with locality. It most commonly inhabits gently flowing sections of forest streams and tributaries where submerged aquatic plants grow thickly. The wate…

Aquarium size

Aquarium base dimensions of 60 ∗ 30 cm24 ∗ 12 in or equivalent should be the smallest considered since this species should be maintained in numbers.

Maintenance

Choice of decor is not especially critical although it tends to show better colouration when maintained in a well-furnished set-up with a dark substrate, and i…

Water conditions

Not written yet

Diet

Probably a micropredator feeding on small insects, worms, crustaceans, and other zooplankton in nature. In the aquarium it's easily-fed but the best condition …

Behaviour and compatibility

This species is very peaceful indeed making it an ideal resident of the well-maintained community tank. As it places no extreme demands in terms of water chemi…

Sexual dimorphism

Mature females are usually rounder-bellied and often a little larger than the slimmer, more colourful males. An alternative method of sexing is to examine the …

Reproduction

This species exhibits no parental care although it does utilise a different spawning method to most small cyprinids as the eggs are attached to the underside o…

This species exhibits no parental care although it does utilise a different spawning method to most small cyprinids as the eggs are attached to the underside of broad plant leaves or other objects rather than scattered randomly. When the fish are in good condition they will spawn often and in a densely-planted, mature aquarium it is possible that small numbers of young may start to appear without human intervention.

However if you want to increase the yield of fry a slightly more controlled approach is required. The adult group can still be conditioned together but a separate tank should also be set up. This should be very dimly lit with the base either left bare or covered with some kind of mesh of a large enough grade so that any eggs that fail to adhere to the plant can pass through but small enough so that the adults cannot reach them. The widely available plastic 'grass'-type matting can also be used and works very well.

The water itself should ideally be of pH 5.0-6.0, 1-5°H with a temperature towards the upper end of the range suggested above. A decent-sized clump of Microsorium, Cryptocoryne, other broad-leaved plant or artificial alternative should also be included. Filtration is not really necessary but you can use a small, air-powered sponge filter if you prefer.

Some breeders of other Trigonostigma spp. report that older fish aged a year or more make the best subjects for spawning which may be the reason why this species is often said to be difficult to breed. Apparently it is trickier to initiate spawning behaviour in younger individuals and they are also are less fecund.

At any rate the best way to condition them is by feeding small amounts of live and frozen foods 2 or 3 times a day in the weeks leading up to a spawning attempt. When the females appear full of eggs and the males are showing their best colours as they display to one another a large (40-50% of tank volume), cool water change should be performed and one or two pairs introduced to each spawning container a few hours later, preferably in the evening.

Spawning usually occurs in the morning hours and is preceded by a flurry of courtship activity by the male(s). Often a pair will perform a number of 'dry runs' over a chosen spawning surface and it may be several hours before any eggs are produced.

Eventually the female will begin to lay small batches of eggs which are fertilised by the male before the next batch is laid. The spawning process is particularly interesting as often a female will choose the underside of a plant leaf and thus the pair will be observed in an inverted position as eggs and sperm are released.

If the pair(s) fail to spawn immediately they can be left in situ but if no eggs have been observed after 3 or 4 days they should be returned to the main group and a different set of fish chosen. There is no need to feed the adults while they are in the spawning tank.

Post-spawning the adults will eat any eggs they find so either they or the eggs themselves should be removed as soon as possible. Incubation is temperature-dependant to an extent but usually takes between 24 and 48 hours with the young free-swimming in around a week. Initial food should be Paramecium or similar introducing Artemia nauplii and/or microworm once the fry are large enough to accept them.

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Where does this come from?

My own experienceFor example, I've kept twelve in a planted 60 cm tank since March 2024.A website I sawFor example, an IUCN Red List assessment, a museum catalogue or a FishBase page.A paperFor example, Marshall et al. (2011), Water temperature differences in interfluvial palm swamp habitats of Paracheirodon axelrodi and P. simulans.A book, or something not onlineFor example, Tappin (2010), Rainbowfishes: their care and keeping in captivity.Something already on the profileFor example, the Behaviour and compatibility section already says this.

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Notes

T. espei is sometimes referred to by the alternative vernacular names 'false harlequin' or 'Espe's rasbora'. It can be confused with the similar-looking T. het…

References

3 on this profile

Name

Scientific name

Described by

Family

Summary

Size and aquarium

Maximum size

Tank size

Water

Temperature and pH

Hardness

Conductivity

Behaviour

Temperament

Social needs

Community suitability

Where it lives

Countries

Supporting text

Etymology

Distribution

Habitat

Aquarium size

Maintenance

Water conditions

Diet

Behaviour and compatibility

Sexual dimorphism

Reproduction

Notes

References

References