Top 10 Rasbora Species Roundup: Compact Schooling Picks
Rasboras are Asian cyprinids that suit Singapore tap water natively — most species evolved in the same Sundaland blackwater systems that drain through the region. The top 10 rasbora species below are ranked by adult size ascending, with the smallest nano picks first. This roundup from Gensou Aquascaping at 5 Everton Park covers schooling thresholds, water tolerance, and sourcing tips. Local fish shops carry most species at consistently low prices, making rasboras one of the best value-per-fish categories in the hobby for serious schoolers and community tanks alike, with most species available year-round at consistent supply.
Rasbora Genus Overview
The trade groups several genera under “rasbora” for convenience: true Rasbora, Boraras (the dwarf species), Trigonostigma (the wedge-marked harlequin group), Microdevario, and Sawbwa. They share preference for soft, slightly acidic, tannin-stained water in the wild and adapt readily to Singapore tap once chloramine is neutralised. Most species school best in groups of ten or more — smaller groups scatter and lose visual cohesion.
1. Chili Rasbora (Boraras brigittae)
Tiny scarlet schooler, 1.8cm, group of ten in 20-litre. SGD 2-3 at Iwarna. Blackwater-leaning — Indian almond leaves intensify colour over two weeks of acclimation. Long-lived (3-4 years) for such a small fish.
2. Exclamation Point Rasbora (Boraras urophthalmoides)
Black caudal spot like an exclamation mark. 1.8cm, group of ten. SGD 2-4. Subtler colour than chili but with a distinctive horizontal black stripe along the body that defines the species visually.
3. Phoenix/Merah Rasbora (Boraras merah)
Subtle red with black-blotched flanks. 2cm. SGD 3-5 at specialist shops. Quality stock shows the dorsal blotch clearly; pale specimens are stressed and rarely recover the full markings even with weeks of stable conditions.
4. Dwarf Rasbora (Boraras maculatus)
Three-spot dwarf, 2cm, group of eight. SGD 3-5. The largest spot pattern of the Boraras genus and a popular choice for blackwater nano displays.
5. Galaxy/CPD (Danio margaritatus)
Technically a Danio but sold alongside rasboras. 2cm, prefers 22-26°C. SGD 4-8 from Petopia. Captive-bred lines now dominate but show subtler patterning than original wild stock.
6. Kubotai Rasbora (Microdevario kubotai)
Vivid neon-green schooler. 2.5cm, group of ten. SGD 4-7. Most striking under low-light planted setups where the green flanks contrast against red stem plants.
7. Espei/Lambchop Rasbora (Trigonostigma espei)
Slimmer body, copper colour, longer wedge than harlequin. 4cm, group of eight. SGD 3-5. Often sold as harlequin by less experienced shops — the body shape and wedge proportion reliably distinguish the two species.
8. Rummy Nose Rasbora (Sawbwa resplendens)
Iridescent silver with red snout — actually a separate genus often grouped with rasboras. 4cm, group of eight, prefers cooler 22-26°C. SGD 6-10. Burmese highland species that struggles in tanks above 28°C without active cooling.
9. Harlequin Rasbora (Trigonostigma heteromorpha)
The classic — black wedge against copper flank. 4.5cm, group of eight, 75-litre. SGD 2-4. Use the dark substrate range to deepen body colour. Five-year lifespan with consistent care.
10. Scissortail Rasbora (Rasbora trilineata)
Largest of the standard rasboras, deeply forked tail with black-and-yellow markings. 8cm, group of six, 90-litre tank. SGD 3-5 at C328 Clementi. Active swimmer — pair with a 90cm aquarium tank for proper cruising space and feed varied micro-pellets from the fish food range. The forked caudal flicks visibly during fast schooling turns and the subtle yellow-and-black tail markings catch overhead lighting in well-lit planted setups.
Indian almond leaves, alder cones and oak leaves stain the water with tannins that deepen body coloration over weeks. Soft acidic conditions also reduce bacterial load and replicate the natural Sundaland blackwater habitat. Drop one almond leaf per 30 litres of tank volume and replace monthly. Within four to six weeks, group coloration intensifies noticeably and breeding behaviour often follows in mature schools. ANS Catappa Leaves and similar local-brand options work identically and are widely stocked across Singapore aquarium retailers and online marketplaces.
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