Are Black Ruby Barbs aggressive?
Barbs can be a bit aggressive in small groups as a general rule. Their stress from being isolated almost always comes out as aggression towards their tankmates. Keep Black Ruby barbs in groups of 6 or more to appease aggressive behaviour.
The black ruby barb (Pethia nigrofasciata, formerly Puntius nigrofasciatus) or purplehead barb is a tropical cyprinid fish endemic to Sri Lanka, where it occurs in forested streams from the Kelani basin to the Nilwala basin. They are found in streams on hills around 1000 ft in elevation.
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