Description
Baby Dolphin Fish (Mormyrus longirostris / Freshwater Dolphin )
📌 Basic Info
Scientific Name: Mormyrus longirostris
Common Names: Freshwater Dolphin, Eastern Bottle-Nosed Mormyrid, Baby Dolphin Fish
Family: Mormyridae (Elephantfish Family)
Order: Osteoglossiformes
Origin: African freshwater rivers and lakes — Zambezi, Luapula, Niger, Lake Malawi, Lake Tanganyika
Size: Up to 75 cm (29 in) in the wild; juveniles in aquariums usually 5–15 cm (2–6 in)
Lifespan: 10 – 15 years
Tank Zone: Middle to bottom dweller
🌊 Water Parameters
TDS: 100 – 300 ppm
pH: 6.5 – 7.5
Temperature: 24 – 28°C (75 – 82°F)
Hardness: 5 – 15 dGH
🐟 Characteristics
Body: Elongated, laterally compressed with a flexible, trunk-like snout.
Coloration: Silvery-gray to brownish with darker markings along the body; juveniles are more patterned.
Fins: Rounded dorsal and caudal fins; anal and pectoral fins are elongated.
Behavior: Mostly peaceful, can be shy; may interact via weak electric signals.
Nature: Nocturnal to crepuscular; uses electroreception to navigate murky waters.
Special Feature: Can emit weak electric fields for communication and sensing surroundings.
🍽️ Food
Type: Carnivorous / Omnivorous
Diet: Live or frozen foods — worms, insect larvae, small fish, shrimp, and sinking carnivore sticks.
Feeding Frequency: Once or twice daily; juveniles require frequent feeding.
Tip: Provide high-protein diet for healthy growth and activity.
🛠️ Maintenance
Tank Size: Minimum 500 liters (130 gallons) for juveniles; adults require much larger tanks (1000+ liters).
Filtration: Strong filtration with moderate water flow; sensitive to poor water quality.
Substrate: Sand or smooth gravel to prevent snout injury.
Decor: Rocks, driftwood, and hiding caves; provide open swimming space.
Lighting: Low to moderate; prefers dim areas or shaded zones.
Water Change: 25–30% weekly for stability and cleanliness.
👥 Social Behavior
Group Size: Can be kept singly or in small groups; avoid overcrowding.
Tank Mates: Peaceful, larger fish; avoid tiny fish that can be eaten.
Avoid: Aggressive cichlids or overly active species.
Compatibility Note: Sensitive to stress; maintain stable water conditions.
✅ Do’s
Provide large, spacious tank with open swimming zones.
Use strong filtration and regular water changes.
Offer protein-rich foods daily.
Maintain stable water parameters.
❌ Don’ts
Don’t keep in small tanks or with overly aggressive fish.
Avoid sharp décor or substrates that can injure the snout.
Don’t expose to bright light constantly.
⭐ Quick Tips
The Freshwater Dolphin is a fascinating, peaceful, and highly intelligent fish. Its trunk-like snout and weak electric abilities make it unique among freshwater aquarium species. Ideal for aquarists with large tanks who enjoy unusual, nocturnal, and interactive fish with a long lifespan.







