Blacktip rasbora

Where they come from

Blacktip rasboras (Rasbora dorsinotata) are Southeast Asian little stream fish. You will mostly see them associated with clear to slightly tea-colored forest waters with lots of plants and leaf litter. That background explains a lot about what makes them settle in: cover overhead, calm flow, and water that is not rock-hard.

Setting up their tank

Think small schooling fish that want to feel hidden, not trapped. A longer footprint beats a tall tank. I would start them in a 20 long style setup if you can, but a well-planted 15-20 gallon works great for a proper group.

• Group size: 8-12+ (they act way calmer and show better color in numbers)
• Temp: mid 70s F is a sweet spot (around 74-78F)
• pH: slightly acidic to neutral is easiest (roughly 6.0-7.2)
• Hardness: soft to moderate; avoid super hard water if you can
• Filtration: gentle flow, lots of bio (sponge or a baffled HOB works well)
• Lighting: medium; floating plants help a ton

Decor-wise, you cannot really overdo plants with these. I like a mix of stem plants for cover, a clump or two of java fern or crypts, and some floaters. A darker substrate and a couple pieces of wood make them feel like they have "edges" to hang around.

What to feed them

They are easy to feed once you remember their mouths are small. Mine did best with tiny foods offered more like "snacks" than one big dump. They are little pickers in the water column.

• Daily staple: fine micro pellets or crushed flake
• Best conditioning foods: baby brine shrimp, daphnia, cyclops
• Frozen options: frozen baby brine, small-size mysis (chopped if needed)
• Occasional: grindal worms or microworms (great for getting shy fish eating)

How they behave and who they get along with

Blacktip rasboras are classic peaceful schoolers. They will do little sparring displays with each other (no damage, just posturing), then go right back to cruising as a group. If you only keep 3-4, they get twitchy and fade into the plants.

• Great tankmates: other small rasboras, peaceful tetras, corydoras, otocinclus, small loaches, shrimp (adults usually fine)
• Use caution with: long-finned slow fish (not because they are mean, but busy schools can stress them)
• Avoid: big semi-aggressive fish, fin nippers, anything that sees 1 inch fish as food

They look best with other calm midwater fish and a quiet bottom crew. In a community, give them the middle lane and plenty of line-of-sight breaks so they do not feel exposed.

Breeding tips

They are egg scatterers, and the adults will happily snack on eggs and tiny fry if they find them. Spawning is doable, but you will have a much better time if you set up a separate small breeding tank rather than hoping for survivors in the display.

• Breeding tank: 5-10 gallons, sponge filter, heater, dim light
• Spawning trigger: heavy feeding with live/frozen for a week, then a slightly cooler water change
• Spawning media: a big clump of java moss, spawning mop, or a mesh/egg crate barrier so eggs drop out of reach
• After spawning: pull the adults the same day if you can
• First foods: infusoria or powdered fry food, then baby brine shrimp once they are big enough

Common problems to watch for

Most issues I have seen with these come from stress, shipping, and tanks that are too bare or too small for a real group. They are not fragile, but they do not forgive messy water and sudden swings.

• Faded color and hiding: usually too few fish, too much light, not enough plant cover, or they feel outcompeted at feeding time
• Ich/white spot after purchase: common if they were stressed in transit; quarantine helps a lot
• Wasting away: can be internal parasites or just not getting enough food (tiny mouths in a fast community)
• Clamped fins and hovering: check ammonia/nitrite, then look at temperature swings and aggressive tankmates
• Jumping: they can hop when startled, especially during the first week

If you are troubleshooting, start with the basics: stable temp, clean water, and a bigger group. Then make sure they actually get food. In a busy community tank, I like to feed a tiny pinch, wait 30 seconds, then feed again so the shy ones get a turn.