Description
Red Tailed Flagtail Barb Scientific Name: Semaprochilodus insignis Common Names: Red Tailed Flagtail, Flagtail Prochilodus, Red Tail Prochilodus
Overview
The Red Tailed Flagtail Barb is a striking, robust freshwater fish known for its silver body and vividly striped tail fin with alternating red and black bands. Native to the Amazon and Orinoco river basins, this species grows large and is best suited to spacious aquariums or public displays. Despite its size, it is generally peaceful and does well in groups, especially when kept in well-oxygenated, current-rich setups that mimic its natural river habitat.
Key Information
Size: Up to 12 inches (30 cm)
Lifespan: 8–10 years or more
Temperament: Peaceful but active; can be skittish
Diet: Herbivore – grazer and detritivore
Swimming Level: Mid to bottom
Habitat & Tank Setup
Tank Size: Minimum 125 gallons; larger for adult groups
Group Size: Can be kept singly but thrive in small shoals (3–6)
Substrate: Fine sand or smooth gravel
Decor: Driftwood, large rocks, open swimming space
Plants: Hardy plants or floating vegetation (may nibble on soft plants)
Lighting: Moderate to bright
Filtration: Strong; needs high oxygenation and some current
Water Parameters
Temperature: 75–82°F (24–28°C)
pH: 6.0–7.5
Hardness: Soft to moderately hard (3–12 dGH)
Water Quality: Excellent water quality is essential due to their size and diet
Feeding
Diet Type: Primarily herbivore
Suitable Foods:
Algae wafers, spirulina-based pellets
Blanched vegetables (spinach, zucchini, peas)
Some protein-based foods in moderation (bloodworms, shrimp pellets)
Feeding Frequency: 1–2 times daily; avoid overfeeding due to large biomass
Tankmates
Compatible With:
Large, peaceful community fish (silver dollars, peaceful cichlids, larger tetras)
Other Flagtails or similar riverine species
Avoid:
Small fish (may be intimidated by size/activity)
Aggressive or highly territorial fish
Care Notes
Requires ample space and good water flow to stay healthy
Will jump when startled – secure tank lid is a must
May graze on biofilm and algae, helping with tank cleanliness
Juveniles are especially social – prefer groups
Strong swimmers; provide horizontal space for natural movement
Fun Fact
In the wild, Red Tailed Flagtails migrate long distances in large schools during flood season. Their flashy tails help them stay together in fast-flowing waters!