Otocinclus Catfish (Otocinclus vittatus)

Otocinclus Catfish (Otocinclus vittatus) is a tiny, peaceful algae eater that earns its keep grazing soft green and brown algae off plants, glass, and decor. Often called the Oto or dwarf sucker catfish, it is one of the best natural cleanup crews for a planted community tank, staying under two inches and never bothering tankmates. Otos are social and a little sensitive, so they do best in groups of six or more in an established, mature aquarium. Browse the rest of our freshwater fish.

Care Guide

• Established tank only: Otos feed on the soft algae and biofilm that grow in a mature tank. Add them to a stable, cycled aquarium that is a few months old, never a brand-new setup.
• Keep a group: They are shoaling fish and feel safest in groups of six or more, where they graze actively out in the open.
• Water: Keep them in clean, well-filtered water at 72 to 79F with a pH of 6.0 to 7.5. They are sensitive to ammonia and nitrite, so stable parameters matter.
• Acclimation: Drip acclimate slowly. Otos ship more delicately than hardier fish, so a gentle, patient acclimation helps them settle in.

Specifications

Compatibility

Otocinclus are model community citizens. They mix beautifully with other small, peaceful fish and inverts and will not bother anyone. Good tankmates include:

• Neon Tetras and other small schooling tetras.
• Cory Catfish as fellow peaceful bottom dwellers.
• Neocaridina shrimp and snails for a complete cleanup crew.

Avoid housing them with large or aggressive fish such as big cichlids that may eat or harass them.

Recommended Foods & Supplies

A planted, algae-friendly tank does most of the feeding, but algae runs out fast with a hungry group, so supplement regularly.

• Sea Veggies Floating Clip for offering blanched zucchini, cucumber, or nori sheets.
• Live aquarium plants to grow the biofilm and soft algae Otos love to graze.
• Algae wafers and spirulina-based sinking foods as a daily staple.

FAQ

Do I really need an established tank?
Yes. Otos rely on the algae and biofilm of a mature aquarium. Adding them to a new, algae-free tank is the most common reason they do not thrive.

How many should I keep?
Six or more. They are shoaling fish that are bolder, healthier, and more active in a group.

Are they safe with shrimp and snails?
Completely. Otos are strict algae and biofilm grazers and will not harm shrimp, fry, or snails.

What do they eat once the algae is gone?
Supplement with blanched veggies on a clip, algae wafers, and spirulina foods so the group always has something to graze.