Description
Black Rainbow Shark (Epalzeorhynchos frenatum – Black Variant)
📌 Basic Info
Scientific Name: Epalzeorhynchos frenatum
Common Names: Black Rainbow Shark, Black Shark, Black Sailfin Shark
Family: Cyprinidae (Carps & Minnows)
Order: Cypriniformes
Origin: Southeast Asia — Thailand, Malaysia, and Indonesia (rivers and streams)
Size: Up to 6 inches (15 cm) in captivity
Lifespan: 6 – 10 years
Tank Zone: Mid to bottom dweller; active and semi-territorial
🌊 Water Parameters
TDS: 100 – 250 ppm
pH: 6.5 – 7.5
Temperature: 22 – 28°C (72 – 82°F)
Hardness: 5 – 15 dGH
🐟 Characteristics
Body: Streamlined, laterally compressed body with dark black coloration and slightly reddish fins; resembles a small freshwater shark.
Behavior: Semi-aggressive; territorial with same species but peaceful with other compatible fish in spacious tanks.
Swimming Style: Active mid-to-bottom swimmer; scrapes algae and explores tank surfaces.
Unique Feature: Dark coloration makes it a striking centerpiece in aquariums.
Nature: Hardy, energetic, and interactive; requires ample space and hiding spots.
🍽️ Food
Type: Omnivorous
Diet: Algae wafers, sinking pellets, blanched vegetables (zucchini, spinach), occasional live/frozen foods
Feeding: Once or twice daily in moderate amounts
Tip: Provide balanced diet including plant matter to maintain health and dark coloration
🛠️ Maintenance
Tank Size: Minimum 55 gallons (210 L) for a single adult; larger preferred for multiple
Filtration: Strong filtration with moderate water flow
Decor: Open swimming space with driftwood, rocks, and hiding areas
Lighting: Moderate — highlights black body and reddish fins
Water Change: 25% weekly to maintain stable water quality
👥 Social Behavior
Minimum Group Size: Can be kept alone or in groups of 3+ in very large tanks
Tank Mates: Peaceful mid to large fish; avoid small, delicate, or highly aggressive species
Avoid: Overcrowding or keeping with very small or slow-moving fish
✅ Do’s
Provide open swimming space and hiding spots
Maintain stable water parameters and moderate current
Feed a varied diet with algae and vegetables
Monitor territorial behavior
❌ Don’ts
Don’t keep in small tanks — stress and aggression may develop
Don’t house with tiny or aggressive fish
Don’t neglect filtration or water quality
⭐ Quick Tips
The Black Rainbow Shark is a striking, semi-aggressive freshwater fish, ideal for medium to large aquariums.
Its dark coloration, energetic swimming, and algae-eating habits make it a dynamic and visually appealing tank inhabitant.
Best suited for aquarists who can provide ample space, stable water, and proper diet.
