🐟 Black Ruby Barb (Pethia nigrofasciata, formerly Puntius nigrofasciatus)
Freshwater Peaceful Schooling Barb • Males Colour Up Red at Maturity • Vulnerable in the Wild — Sri Lankan Endemic
 
📋 The Black Ruby Barb, also called the Purple-Headed Barb, is a small schooling barb endemic to the forest streams of southwestern Sri Lanka. Mature males in good condition turn deep red across the head and forebody against a dark body, while females stay bronze-gold with dark vertical bars.
Good to know: the red colouring appears as males mature and settle in, so small juveniles look bronze with dark bars. Good food, a planted tank, dim lighting and a dark substrate all help bring it out.
It is peaceful and can be a little shy. It is not the relentless fin-nipper that tiger barbs are, but a group that is too small can still nip, so keep at least six with calm, similar-sized tank mates.
The species is Vulnerable in the wild, and Sri Lanka prohibits exporting wild fish, so aquarium stock should be commercially bred.
 
💡 Highlights
✨ Red-Headed Males: Deep red head and forebody on a dark body when mature
⚪ Peaceful and Sometimes Shy: Best with calm tank mates
📏 Small: Around 6–7cm
👥 Schooling Fish: Keep at least six
🌿 Suits Planted Tanks: Dark substrate and dim light deepen the colour