Scissortail Rasbora (Rasbora trilineata) Care Guide
A graceful, active schooling fish named for its deeply forked tail with bold black and white markings that resemble scissors when opening and closing during swimming.
Compiled by Aquairi from published sources · Published · Updated
Overview
Rasbora trilineata is a species in the family Cyprinidae. A graceful, active schooling fish named for its deeply forked tail with bold black and white markings that resemble scissors when opening and closing during swimming. One of the largest rasboras, reaching 15cm. Hardy and peaceful.
Taxonomy
- Family: Cyprinidae
- Genus: Rasbora
- Scientific name: Rasbora trilineata
- Other names: Three-lined Rasbora
- Origin: Southeast Asia
Habitat
Native to the Mekong and Chao Phraya basins and the Malay Peninsula, Sumatra and Borneo. Inhabits flowing forest streams and rivers, often in large shoals near the surface. The deeply forked tail with black-and-white markings opens and closes like scissors as the fish swims.
Tank requirements
- Minimum tank volume: 150 L
- Temperature: 23-28 °C
- pH: 6-7.5
- GH: 2-15 °dGH
- Water flow: moderate
- Adult size: 10-15 cm
- Lifespan: 5-7 years
- Recommended group size: ≥ 6
- Difficulty: beginner
Diet
Classified as omnivore. Recommended feeding frequency: 2x daily. In captivity, offer a varied diet appropriate to the species — quality prepared foods supplemented with frozen or live items of suitable size.
Compatibility
- Temperament: peaceful
- Swimming level: middle
- Compatible tank mates: Other Rasboras, Corydoras, Gouramis, Bala Shark
- Avoid with: Small Nano Fish, Aggressive Fish
Breeding
- Breeding strategy: egg-scatterer
- Breeding difficulty: intermediate
Scissortail Rasbora Breeding Guide
Overview
Rasbora trilineata is an egg-scattering, continuous spawner that exhibits no parental care. In a well-planted, mature aquarium fry may appear on their own, but for serious breeding a dedicated spawning tank is set up to protect the eggs from the adults.
Sexing
Mature females are noticeably rounder-bellied and often a little larger than the males.
Conditioning
Condition pairs together, then introduce one or two pairs per spawning container. Feeding live and frozen foods and gradually adding cool water every few hours helps initiate spawning.
Breeding Setup
- A shallow, half-filled, dimly lit container; a tank of about 48 x 12 x 12 inches (120 x 30 x 30 cm) works for this larger rasbora
- A mesh base large enough for eggs to fall through but preventing adult access, or plastic grass matting
- Pristine water, slightly acidic to neutral pH
- Temperature at the upper end of the species range, about 73-77°F (22-25°C)
- An internal power filter directing flow along the tank's length, later swapped for a mature sponge filter
Spawning Behavior & Trigger
Spawning is initiated by gradually adding cool water every few hours alongside live and frozen feeding. Eggs are scattered and fall through the mesh out of reach of the adults, and multiple spawning events occur before the females are depleted.
Egg & Fry Care
Remove the adults after about two days because they consume eggs, and switch the power filter to a mature sponge unit to protect the fry. Incubation usually takes between 18 and 48 hours, and the fry become free-swimming 24 to 48 hours later. First foods are Artemia nauplii and/or microworm.
Common Challenges
Maintaining pristine water and removing the adults promptly are the main keys; the staggered spawning means the breeder should expect several batches rather than a single large one.