Lambchop Rasbora (Trigonostigma Espei)

A Schooling Gem for Planted Aquariums

The Lambchop Rasbora (Trigonostigma espei), also known as the Slim Harlequin Rasbora, is a slender, elegant nano fish prized for its warm copper-orange body and the distinctive lambchop-shaped black marking that runs along its flank. Peaceful, active, and stunning in groups, this species is a staple choice for planted community tanks and nano aquascapes alike.

Native to the slow-moving, tannin-rich waters of Southeast Asia, the Lambchop Rasbora thrives in soft, slightly acidic conditions and looks spectacular when schooling together under aquarium lighting.

Overview

Appearance

The Lambchop Rasbora has a slender, streamlined body with a warm golden-orange to copper hue. Its most distinctive feature is the dark, lambchop-shaped blotch on the rear half of the body — narrower and more elongated than that of the closely related Harlequin Rasbora (T. heteromorpha). Under good lighting, their bodies shimmer with a subtle metallic sheen that makes a school truly eye-catching.

Water Parameters & Tank Setup

• Temperature: 23 – 28°C (73 – 82°F)
• pH: 6.0 – 7.5
• General Hardness (GH): 2 – 10 dGH (soft water preferred)
• Tank Size: Minimum 40 L (10 gallons)
• Schooling: Best kept in groups of 8 or more for natural behaviour and confidence
• Plants & Decor: Thrives in densely planted tanks; floating plants and driftwood mimic their natural habitat
• Lighting: Moderate; their copper colouration glows beautifully under warm-toned lighting

Diet & Feeding

• Staple: High-quality micro pellets or fine flake food
• Treats: Baby brine shrimp, daphnia, and micro worms

Feed small amounts 2–3 times daily. Live and frozen foods will enhance their natural colouration.

Compatibility & Tank Mates

• Other small, peaceful rasboras and tetras
• Dwarf gouramis and bettas (with caution)
• Corydoras and small loaches
• Dwarf shrimp — generally safe with adults

An ideal companion for nano planted tanks and community aquascapes. Avoid large or aggressive tankmates.

The Lambchop Rasbora is a timeless, versatile schooling fish that brings warmth, movement, and natural beauty to any aquarium. A must-have for the planted tank enthusiast.