Blackline Rasbora (Rasbora daniconius)

Family: Cyprinidae

Blackline Rasbora — a Cyprinidae freshwater fish. Reaches 11.2–16.5 cm; keep at 24–26 °C.

Care parameters

Water temperature
24–26 °C
pH
6.2–7
GH hardness
5–15 dGH
Adult length
11.2–16.5 cm
Minimum tank
327 L
Water layer
Active throughout the water column
Difficulty
Moderate
Temperament
Mostly peaceful; some species nip fins

Species overview

A Cyprinidae species: Rasbora daniconius lives active throughout the water column over gravel. Mostly peaceful; some species nip fins. Adults reach 11.2–16.5 cm. It is one of the aquarium-kept Rasbora species we profile, alongside Rasbora borapetensis, Rasbora caudimaculata, Rasbora einthovenii.

Native biotope

Habitat
Clear streams and rivers over gravel
Flow
Moderate, well-oxygenated current
Dissolved O₂
Appreciates well-oxygenated water

Aquascape & hardware

Substrate
Fine gravel and sand
Hardscape
Water-worn stones and driftwood
Plants
Hardy rooted plants along the margins

Temperament, diet & tankmates

Schooling
Shoaling; keep in groups of 6 or more
Diet
Omnivore; prepared foods with regular vegetable matter
Recommended tankmates
  • Similar-sized peaceful community fish — Similar size and water needs
Avoid keeping with
  • Much smaller fish — May outcompete or bully tiny tankmates

Breeding & notes

Sexual dimorphism
Males often slimmer and more colourful
Breeding method
Egg-scatterer; no parental care

Frequently asked questions

Is Blackline Rasbora easy to keep?

Intermediate difficulty. Mostly peaceful; some species nip fins; shoaling; keep in groups of 6 or more.

What temperature and water chemistry does Blackline Rasbora need?

Aim for 24–26 °C. Room temperature to heated, depending on origin; 24–26 °C recorded range.

How big does Blackline Rasbora get, and what tank size?

Expect 11.2–16.5 cm as an adult, living active throughout the water column. A 327 L tank or larger gives it room.

What does Blackline Rasbora eat?

Omnivore; prepared foods with regular vegetable matter. Vary the menu — quality flakes or pellets plus frozen or live foods.

Can Blackline Rasbora live with other fish?

Mostly peaceful; some species nip fins; shoaling; keep in groups of 6 or more. Good company: Similar-sized peaceful community fish — Similar size and water needs. Keep away from Much smaller fish — May outcompete or bully tiny tankmates.

Where does Blackline Rasbora come from?

It lives in clear streams and rivers over gravel. Moderate, well-oxygenated current; Appreciates well-oxygenated water.

Does Blackline Rasbora jump?

Jumping is not a known issue; cover the tank anyway during water changes.

How does Blackline Rasbora breed?

In the aquarium: egg-scatterer; no parental care. Males often slimmer and more colourful.