Red-tailed Flag Tetra

About

Occasionally showing up in the trade under the name red-tailed flag tetra, Hyphessobrycon agulha is a small characid from the Madeira River basin in South America that most hobbyists have never had the chance to keep. It gives its name to the agulha species group within the genus, a cluster of closely related tetras that share a dark lower body, a horizontally elongate humeral spot, and a broad asymmetrical lateral band. In this species the dark stripe runs the full length of the body and continues onto the central rays of the tail, a useful identification point when trying to tell it apart from similar tetras. It stays small, tops out well under two inches, and is thoroughly peaceful, making it a reasonable choice for a well-thought-out community tank. It does best alongside other small characids, hatchetfishes, lebiasinids, and small catfishes rather than anything large or boisterous. Like most schooling tetras it genuinely benefits from being kept in a group of eight or more, and mixing it with other schooling species seems to bring out more relaxed, natural behavior. Breeding has not been documented in the hobby. The species is genuinely uncommon in the trade, so if you come across a group, it is worth picking up.