Fish
Scissortail Rasbora
Rasbora trilineata · also called scissortail rasboras
Flicking a boldly banded, forked tail open and shut like a pair of scissors, a scissortail rasbora glides through open water in a tight school, its constant tail motion as recognisable as the pattern that gives the species its name.
Overview
The scissortail rasbora, Rasbora trilineata, is an active, larger-bodied schooling fish native to rainforest stream and wetland habitat across Indonesia, Malaysia, and Thailand in Southeast Asia. Its distinctive scissoring tail motion, bold black-and-white tail banding, and generally peaceful temperament make it one of the more visually and behaviourally distinctive rasboras kept in aquariums, particularly in larger community tanks with ample swimming room.
A tail that never stops moving
The scissortail rasbora’s constant tail-flicking motion sets it apart from most other schooling fish, its boldly banded fin lobes opening and closing in a rhythm that gives the species both its striking visual signature and its descriptive common name.
Status
Least Concern, remaining widespread across suitable rainforest stream and wetland habitat throughout Indonesia, Malaysia, and Thailand.
Scissortail Rasbora: common questions
Why does the scissortail rasbora keep flicking its tail?
This species repeatedly flicks the two lobes of its forked, black-and-white banded tail fin open and shut in a motion resembling scissors opening and closing, a near-constant habit that gives the species its common name and is thought to relate to swimming coordination within a school.
How big does the scissortail rasbora get?
This species grows notably larger than many other popular rasboras, reaching lengths that make it one of the bigger members of the group commonly kept in aquariums, so it benefits from a longer tank with plenty of open swimming space.
Is the scissortail rasbora a peaceful community fish?
Yes, this species is generally peaceful and well suited to a mixed community aquarium alongside other similarly sized, non-aggressive fish, though its active, fast-swimming nature means it does best with adequate open space to move through.
Where does the scissortail rasbora come from?
This species is native to rainforest stream and wetland habitat across Indonesia, Malaysia, and Thailand in Southeast Asia, where it forages in schools through both open and vegetated stretches of slow-moving water.