Jaguar Dolphin Catfish (3-3.5”)

Ageneiosus marmoratus

Maximum Size & Lifespan:
can reach up to 18-24" in length 

 They can live 12–15 years with proper care, potentially longer in optimal conditions.

Recommended Aquarium Size, Water Changes & Care:
Due to its large adult size and active swimming habits, a minimum aquarium size of 500–750 liters (125 gallons) is recommended for a single specimen, with larger setups for groups or mixed species communities.

Juveniles can be raised in a smaller 40-90 gallon fish tank for better observation.

They require:

• Filtration: Strong external filtration with high oxygenation, as they produce substantial waste.

• Water Parameters: pH 6.0–7.5

•  Temperature 75–82°F

• Water Changes: Large, regular water changes — 30–40% weekly — to maintain pristine conditions.

• Décor: Driftwood, large rock structures, and open swimming spaces. They are crepuscular/nocturnal but will be active in low light. Use a sandy or smooth gravel substrate to avoid barbel damage.

Tankmates:
Best with medium to large, robust fish that can’t be swallowed, such as:

• Large cichlids Severums, Geophagus, Silver Dollars, Arowana (With appropriate sizing)
  

• Other large South American catfish (with compatible temperament)
  Avoid small fish, slow long-finned species, and aggressive territorial bottom dwellers.

Diet:
A carnivore with opportunistic predatory habits. In the aquarium, feed:

•  frozen tilapia and shrimp

• Sinking carnivore/massivore pellets

• Overview:
  Ageneiosus marmoratus is a large, fast-swimming predatory catfish native to South America, known for its elongated body, upturned mouth, and attractive marbled pattern. Though powerful and predatory, it is generally not overtly aggressive toward similarly sized fish. Its streamlined body and hunting style make it well suited for large river-style aquaria with good current and dim lighting.

Natural Environment:
This species is found in the Amazon, Orinoco, and Paraná river basins across Brazil, Peru, Bolivia, Paraguay, and Argentina. It inhabits main river channels, flooded forests, and large tributaries, often staying near submerged logs and woody debris. It is a nocturnal predator, feeding on fish, crustaceans, and insects in its natural habitat.