Redflank Bloodfin

About

The redflank bloodfin (Aphyocharax rathbuni) is a small tetra from the Paraguay River basin in South America, sometimes sold under the name green fire tetra. It carries a neat combination of a silvery-green body with a vivid red flush along the flank and into the tail, making it easy to identify once you know what you're looking at. Like many tetras, this species is fundamentally a shoaler, and keeping a group of at least six is essential for its well-being and for seeing its best coloration and behavior. Here's where hobbyists need to pay attention though: despite a generally peaceful temperament, it has a well-documented habit of nipping fins. That rules out slow-moving or long-finned tankmates like many cichlids and anabantoids. Pair it instead with active, robust fish that can hold their own. For breeding, the redflank bloodfin is a group-spawning egg-scatterer and not especially difficult to breed if you condition the adults well on live and frozen foods beforehand. Females swell noticeably when ripe, spawning often follows within a day of moving fish to a breeding setup, and the fry grow at a decent clip with good water quality. A rewarding species once you understand its quirks.