Looking for the ultimate natural cleanup crew for your planted aquarium? The Otocinclus Catfish (commonly known as the Oto Catfish or Dwarf Suckermouth Catfish) is renowned as the hard-working hero of the freshwater aquarium hobby. Petite, peaceful, and endlessly active, these gentle algae eaters work around the clock controlling soft green algae, brown diatom algae, and organic biofilm without disturbing delicate live aquatic plants or substrate.

Key Features & Care Specifications

• Place of Origin: Native to the warm river basins, floodplains, and slow-moving tributaries of South America—primarily across the Amazon, Orinoco, and Paraná River basins in Brazil, Peru, and Paraguay. In the wild, they inhabit heavily vegetated riverbanks in large shoals.

• Care Level: Moderate. They thrive best in mature, established planted aquariums with stable water parameters and abundant natural biofilm/algae growth.

• Tank Size: Minimum 10 to 20 gallons. As social schooling fish, Otocinclus must be kept in groups of 6 or moreto ensure they feel safe, active, and stress-free.

• Environment & Tank Setup: Provide a densely planted aquarium setup using broad-leaf plants (e.g., Anubias, Amazon Swords, Java Fern), smooth river rocks, and natural driftwood. A soft sand or smooth gravel substrate protects their sensitive barbels, while moderate water flow and good oxygenation simulate their natural riverbank habitat.

• Feeding & Diet: Primary herbivores. While they naturally graze on soft green algae and brown diatom algae, supplemental feeding is crucial to prevent starvation. Feed them sinking spirulina wafers, algae pellets, and blanched fresh vegetables (like zucchini, cucumber slices, or spinach) 2–3 times weekly.

• Tank Mates: 100% peaceful community fish. Ideal tank mates include Neon Tetras, Rasboras, Corydoras Catfish, Guppies, Dwarf Cichlids, as well as freshwater shrimp (Cherry Shrimp, Amano Shrimp) and snails. Avoid large, aggressive, or predatory species like Oscar Cichlids.

• Breeding: Breeding in home aquariums is rare but achievable. Triggered by cooler water changes (simulating rainy season conditions), females lay adhesive eggs on plant leaves or tank glass. Fry hatch in 3–5 days and feed on micro-algae, infusoria, and liquid fry foods.

Quick Water Parameters

• Temperature: 72°F – 79°F (22°C – 26°C)

• pH Range: 6.0 – 7.5

• Hardness: 2 – 10 dGH

• Max Size: 1.5 – 2.0 inches

PLEASE READ BEFORE ORDERING

• The photos shown on fish product pages are representations of adult fish and are NOT the actual fish that you will be receiving. 
• Please visit our “Ordering/Shipping fish” page prior to checking out to familiarize yourself with our process.
• We ship fish exclusively using overnight shipping with either FedEx or UPS. We will not ship fish with lesser expensive shipping services like “Ground” or “Priority Mail”. This is to ensure the safety of the fish.
• Unless specified, all fish are sold as unsexed.