Edit Trigonostigma heteromorpha

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Name

Scientific name

Trigonostigma heteromorpha

Described by

Authority Duncker, Year 1904

Family

Cyprinidae

Summary

The harlequin, Trigonostigma heteromorpha, is a small cyprinid from southern Thailand, Peninsular Malaysia, Singapore and Sumatra. First ex…

Size and aquarium

Maximum size

45mm, standard length

Tank size

Minimum length 60 cm, Minimum depth 30 cm

Water

Temperature and pH

Temperature 21–28°C, pH 5–7.5

Hardness

1–12dGH

Conductivity

Not recorded

Behaviour

Temperament

Peaceful

Community suitability

Community-safe

Where it lives

Countries

Indonesia, Malaysia, Thailand

Supporting text

Etymology

Not written yet

Distribution

Type locality is 'Kuala Lumpur, Selangor, Malaysia', but this species is usually quoted as being native to southern Thailand, Peninsular Malaysia, Singapore, a…

Type locality is 'Kuala Lumpur, Selangor, Malaysia', but this species is usually quoted as being native to southern Thailand, Peninsular Malaysia, Singapore, and the Greater Sunda islands of Borneo and Sumatra.

Thai populations seem to be restricted to the district of Narathiwat close to the border with Peninsular Malaysia. In the latter it is more widely-distributed and has been collected from areas of peat swamp forest in the states of Selangor, Kelantan, Terengganu, Pahang, and Johor.

In Singapore it is found in Nee Soon Swamp, one of the last remaining pockets of pristine freshwater forest swamp found in the central catchment area of the island.

The extent of its distribution in the Greater Sunda Islands is less clear. While it certainly occurs on the island of Bintan in Riau Islands province, Sumatra, we've been unable to find definitive information regarding the mainland other than a vague reference to the city of Medan in the north (the species is said to range throughout northern Sumatra). Similarly there appears not to exist a single confirmed occurence from Borneo.

The fish are known to vary somewhat depending on collection locality, with those collected from Johor and southern Thailand having an overall smaller, slimmer appearance than the Singapore and Sunda Island populations (see 'Notes').

Wild caught examples are rare in the hobby as it's produced on a commercial basis in several countries.

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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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DOI

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Title

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Authors

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Year

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Pages

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Anything worth adding

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Habitat

Mostly inhabits gently flowing sections of forest streams and tributaries where submerged aquatic plants such as Cryptocoryne species grow thickly. The water i…

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

Stomach analyses of wild specimens have revealed it to be a micropredator feeding on small insects, worms, crustaceans and other zooplankton. In the aquarium i…

Behaviour and compatibility

This species is very peaceful indeed making it an ideal resident of the well-maintained community tank and an unreserved recommendation for those new to fishke…

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…

Notes

T. heteromorpha was first exported for aquaria in the early 1900s and has gone on to become one of the most familiar, enduring species in the hobby. It's suffe…

References

4 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