Blackline Rasbora (Rasbora borapetensis)

The Blackline Rasbora (Rasbora borapetensis) is found in Asia’s Mekong, Chao Phraya, and Mae Klong river basins as well as the northern Malay Peninsula.

It is a midwater to surface schooling Cyprinid that prefers slow moving water and is collected close to the surface in ponds, ditches, canals and the margins of reservoirs, usually in water less than 6 feet deep.

Blackline Rasboras are also known by tropical fish keeping enthusiasts as the red tailed rasbora, brilliant rasbora, or bora bora rasbora.

The blackline rasbora is a beautiful streamlined fish that grows to almost 2 1/2″ in length.  Their body is silver, with a dark brown or black lateral stripe underneath a gold lateral stripe, that reaches from the gill opening to the front of the base of the caudal fin.  The caudal fin base is bright red and unlike Rasbora einthovenii, it is absent any black pigmentation.

Male and female blackline rasboras are identical except that the females are slightly larger and broader when viewed from above.

Blackline Rasboras are a popular aquarium fish that prefer a densely planted tank with minimal water movement and plenty of space to swim. They are true schooling fish that should be kept in tight schools of at least 8 to 10 fish.   A dark substrate and the addition of some floating plants, driftwood roots or branches to diffuse the light entering the tank is also appreciated by the fish and provides a more natural environment.

Blackline Rasboras are peaceful, active and hardy when housed with other peaceful species like plecos, loaches, large and small tetras, livebearers, or rainbowfish.   They do best in water with a pH range of 6.5 to 7.0, water hardness (dH) of 5 to 12, and temperatures between 71 and 79 °F.

Like many  cyprinids, the Blackline Rasbora is a continuousm, egg scattering,  spawner that exhibits no parental care.  Females will spawn several times scattering 5 to 15 eggs over a period of time until a typical batch of 30 to 50 eggs are deposited.  Eggs typically hatch between 18 and 48 hours after spawning and the young are free swimming 24 to 48 hours later.

Paramecium should be fed initially until the fry are able to accept microworms.

Blackline Rasboras do well on a diet of quality flake food, frozen or freeze dried bloodworms, daphnia, and tubifex.

Blackline rasboras are usually available for purchase when they are 1 1/2″ long.  Wild caught fish are increasingly rare in the hobby and are being produced commercially in several countries.

Rasbora borapetensis

Rasbora borapetensis

 

 

 

 

 

 

Minimum Tank Size: 20 gallons
Care Level: Moderate
Temperament: Peaceful
Hardiness: Very Hardy
Water Conditions: 71-79° F, KH 3-7, pH 6.5-7.0
Color Form: Silver, Black, Gold
Diet: Omnivore
Origin: Asia
Family: Cyprinidae
Life Span: 5 to 7 Years
Aquarist Experience Level: Beginner

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