Lambchop Rasbora

Trigonostigma espei

Also known as: Espe's rasbora, Espei rasbora, False harlequin

Water Parameters

• Temperature: 22–28°C
• pH: 5.5–7.5
• Hardness (GH): 36–143 ppm (2–8 dGH)

Values above are general hardness (GH). For carbonate hardness (KH), the buffer that keeps pH stable, see the water parameters guide.

Care Summary

A nano-tank favourite and, to many keepers, the prettier of the harlequin rasboras: where the harlequin carries a solid black triangle, the lambchop wears a narrower, hook-shaped mark on a richer orange body, and a tight school flowing through a planted tank is a warm, coordinated drift of colour. Smaller and better suited to nano tanks than its harlequin cousin, it is hardy, peaceful, and undemanding once settled, asking only for stable, ideally soft and slightly acidic water and the security of a proper school. Tank-bred fish are widely available and adapt well to a range of conditions. An excellent, gentle, and genuinely beginner-friendly schooling fish for a small planted community.

Tankmates

A smaller, slimmer cousin of the harlequin rasbora, distinguished by a hook-shaped black 'lambchop' marking on a warm copper-orange body. Keep it in a group of at least eight, ideally more, where it schools tightly and the colour deepens. Exceptionally peaceful and small enough to be a genuine non-threat to adult shrimp, which makes it one of the better dither fish for a planted shrimp tank, though it will take shrimplets. Best with other small, peaceful nano species: micro-rasboras, small tetras, pygmy corydoras, and otocinclus. Avoid boisterous or large tankmates that will intimidate or eat it. Shows its best colour in a soft, planted, dimly-lit blackwater-style tank.

Compatible with

• Ember Tetra
• Chili Rasbora
• Harlequin Rasbora
• Celestial Pearl Danio
• Pygmy Corydoras
• Otocinclus
• Cherry Shrimp
• Sparkling Gourami

Avoid keeping with

• Betta
• Angelfish
• Large Cichlids
• Fin Nippers

Common Problems

• loose schooling and faded colour in groups smaller than 8
• stress from boisterous tankmates
• ich
• pale colour in bright, bare tanks

Sources: seriouslyfish.com, fishbase.org · Last updated: 2026-06-20