Description
Lambchop Rasbora (Trigonostigma espei)
Overview
Trigonostigma espei, commonly known as the lambchop rasbora or false harlequin rasbora, is a small, peaceful freshwater fish from the Cyprinidae family (subfamily Danioninae), native to slow-moving, heavily vegetated blackwater streams, pools, and swamps in Southeast Asia, including southern Thailand, Cambodia, and Phu Quoc Island, Vietnam. Named for its distinctive black, lambchop-shaped marking on a coppery-red to orange body, it grows to 2.5–4 cm. Males are slimmer with brighter colours and sharper markings, while females are stockier with rounder abdomens and duller hues. Hardy and low-maintenance, they are ideal for beginners but require shoaling groups and pristine water. Most aquarium specimens are captive-bred due to habitat loss.
Care Requirements
Tank Size:
Minimum 60L for a shoal of 8–10; 75L or larger preferred for larger groups to support shoaling and activity. Base dimensions of at least 60 x 30 cm recommended.
Water Parameters:
- Temperature: 23–28°C; optimal 27°C for breeding.
- pH: 5.5–7.0 (acidic to neutral; breeding requires 5.5–6.5).
- Hardness: 2–12 dGH (soft water).
- Ammonia/Nitrite: 0 ppm.
- Nitrate: <50 ppm (ideally <15 ppm, as they are sensitive to nitrates).
- Substrate: Dark fine sand or gravel to enhance colouration; add leaf litter (e.g., Indian almond, beech, oak) for tannins to mimic blackwater habitats.
- Décor: Dense low-light plants (e.g., Java moss, Cryptocoryne, Anubias) and floating plants for shade and cover. Include driftwood or roots for hiding spots, ensuring open swimming space.
- Filtration: Gentle flow (4–5x tank volume/hour) using sponge or hang-on-back filters with peat or blackwater extract to maintain acidic conditions.
- Lighting: Low to moderate; floating plants diffuse light to mimic shaded streams.
- Other: Tight-fitting lid essential, as they may jump when stressed. Acclimatize slowly to avoid shock.
Maintenance
- Water Changes: 20–30% weekly or 10–15% biweekly with dechlorinated water matching tank parameters to prevent nitrate buildup and pH swings. Use anti-chlorine agents.
- Tank Cleaning: Siphon uneaten food and debris; lightly vacuum substrate to preserve beneficial bacteria. Replace leaf litter periodically for tannins.
- Testing: Weekly monitoring of pH, hardness, ammonia, nitrite, and nitrate using a reliable test kit to maintain stability.
- Equipment Check: Ensure filters provide gentle flow, heaters maintain stable temperatures, and lid is secure.
Diet
- Type: Omnivorous micro-predator; feeds on zooplankton, small invertebrates, and plant matter in the wild.
- Foods:
- Dry: High-quality micro-pellets, crushed flakes, or granules (e.g., Fluval Bug Bites, Hikari Micro Pellets).
- Live/Frozen: Daphnia, brine shrimp, cyclops, bloodworms, mosquito larvae (2–3 times weekly for colour and breeding).
- Plant-Based: Spirulina flakes, blanched vegetables (e.g., lettuce, zucchini) for variety.
- Feeding: Small portions 2–3 times daily, consumed within 1–2 minutes to avoid water fouling. Their small mouths require fine foods.
- Notes: Varied diet enhances colouration, especially males’ coppery-red hues. They graze on tank biofilm, supplemented by leaf litter.
Behaviour and Compatibility
- Temperament: Peaceful but timid; active shoalers that may nip fins of slow-moving fish if stressed or in small groups.
- Social Behaviour: Strictly shoaling; keep 8–10 or more (1–2 females per male) to reduce stress and encourage schooling and male displays. Solitary or small groups (<6) become shy, stressed, and disease-prone.
- Compatible Tankmates:
- Small, peaceful fish: Neon tetras, celestial pearl danios, sparkling gouramis, white cloud mountain minnows, other small rasboras.
- Bottom-dwellers: Pygmy Corydoras, kuhli loaches, Otocinclus.
- Incompatible: Large or aggressive fish (e.g., cichlids, tiger barbs), slow-moving or long-finned fish (e.g., bettas, guppies), or other Trigonostigma species (e.g., T. heteromorpha, T. hengeli) to avoid hybridization or competition.
- Notes: Dense vegetation and large shoals reduce skittishness. They swim in mid-to-upper tank levels and may play in gentle filter currents.
Breeding Behaviour
Breeding Type: Egg scatterers; attach adhesive eggs to the underside of broad-leaved plants, unlike most cyprinids. No parental care.
Picture for illustrative purposes only. Either come in store to view available stock or request pictures to be sent to you.
Please Note: Due to variations within species resulting from age, region, sex, etc., the actual livestock may not look identical to the image. Approximate size range may also vary between individual specimens.
