🐟 Costae Tetra (Moenkhausia costae)
A Shimmering Silver Body With an Iridescent Blue-Green Sheen • A Bold Black Stripe Running From Mid-Body Through the Tail • One of the Tightest-Schooling Tetras in the Hobby
 
📋 The Costae Tetra, also known as Costa's Tetra or the Blackline Tail Tetra, has a shimmering, partially translucent silver body with an iridescent blue-green sheen, marked by a bold black stripe running from the mid-body up through the tail fin.
It comes from eastern Brazil, in the heavily vegetated margins of the São Francisco and Itapicuru river basins, an uncommon species in the trade rather than a widely imported staple. Every Costae Tetra we ship is feeding well.
This is one of the tightest-schooling tetras in the hobby, famous for how closely a group moves together, with the black markings blending into a striking, almost zebra-like pattern as they swim. It's a hardy, adaptable species once settled, though it can turn nippy in smaller groups, so a proper school of 6-10 or more keeps this spread out and the fish noticeably calmer. It's also a known jumper, so a secure lid matters. A well-planted tank with dark substrate and background shows off its subtle colouration best. It reaches 5-7cm, so a 75L tank suits a school well.
 
💡 Highlights
⚪ Shimmering Silver Body: An iridescent blue-green sheen catches the light
⚫ Bold Black Tail Stripe: Running from mid-body through the tail fin
👥 Exceptionally Tight Schooling: One of the tightest-schooling tetras in the hobby
💎 An Uncommon Find: Not widely imported, a real rarity for collectors
⚠️ A Known Jumper: A secure, tight-fitting lid is essential