Flagtail Prochilodus

Flagtail Prochilodus (Semaprochilodus insignis)

The Flagtail Prochilodus is a large, peaceful schooling fish known for its striking silver body and bold red-and-black “flag” patterned tail. Native to the Amazon and Orinoco river basins, it is a popular choice for large tropical aquariums thanks to its constant movement, active grazing, and impressive coloration.

This species can grow up to 30–35 cm and should be kept in a spacious tank of at least 450 litres. They thrive in groups of 5 or more, and a long tank with strong filtration, good oxygenation, and open swimming space is ideal. A soft sand or fine gravel substrate with some driftwood and smooth rocks will replicate their natural environment.

Flagtail Prochilodus are herbivores and detritivores—perfect for helping control algae and leftover food. Feed them a balanced diet of spirulina wafers, algae pellets, blanched greens (such as spinach or zucchini), and occasional treats like bloodworms or brine shrimp.

This species is peaceful and mixes well with other large, non-aggressive fish such as silver dollars, bala sharks, larger tetras, and plecos. However, they may show mild aggression toward their own kind if not kept in a group.