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Harlequin rasbora (Trigonostigma heteromorpha)
AI illustration, not an ID reference

Harlequin rasbora

Trigonostigma heteromorpha

FishFreshwater

Care level
Easy
Temperament
Peaceful
Recommended tank
60 L
Maximum size
4.5 cm
Temperature
22–27 °C
pH
6–7.5
Group size
≥ 8
Diet
Omnivore

Care at a glance

The harlequin rasbora, recognisable by the black triangle on its flank, is one of the friendliest schooling fish for a community tank. Unlike many tetras it leaves plants and slow tankmates completely alone, and its coppery-orange glow looks superb in a planted aquarium.

Keep it in a generous school; the fish then cruise calmly and tightly together in the middle water layer. It is undemanding about water values as long as you avoid extremes, and happily takes any small food. An ideal pick alongside other peaceful species from Southeast Asia.

Related species

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Values are mainstream hobbyist guidance, not gospel — always watch what your own animals need.