Otocinclus
Otocinclus macrospilus · Loricariidae
Also known as Oto, Dwarf sucker
Intermediate
A 4 cm biofilm grazer for mature planted tanks; fragile in a brand-new setup.
In short: An otocinclus needs at least 60 L (16 US gal), water at 21–27 °C (70–81 °F) and pH 6–7.5. It is peaceful, best kept in groups of 6 or more, and rated intermediate to keep.
- Minimum tank
- 60 L (16 US gal)
- Temperature
- 21–27 °C (70–81 °F)
- pH
- 6–7.5
- Adult size
- 4 cm (1.6 in)
- Group size
- 6+
Care requirements
- Minimum tank volume
- 60 L (16 US gal)
- Temperature
- 21–27 °C (70–81 °F)
- pH
- 6–7.5
- Hardness
- 2–15 dGH
- Lifespan
- 3–5 years
- Diet
- Herbivore — soft green algae, biofilm, blanched courgette.
- Care level
- Intermediate
Origin & habitat
- Native region
- Amazon and Orinoco basins
- Water type
- Freshwater
- Biotope
- Vegetated stream margins
- Natural conditions
- Soft, warm, oxygenated water with plenty of grazing surface.
Behaviour & stocking
- Temperament
- Peaceful
- Minimum group
- 6 fish
- Swims
- All levels
- Good tank mates
- Neon tetraCorydorasCherry shrimpRasboras
- Avoid
- CichlidsBettaAnything predatory
Breeding & difficulty
- Breeding difficulty
- Advanced
- Sexing
- Females are wider across the body.
- Notes
- Rarely spawns in captivity; most stock is wild-caught.
- Common ailments
- Starvation in algae-free tanksShipping stress deaths
Will it fit your tank?
Sign in and AquaLog compares Otocinclus against every tank you track — volume, water type, temperature and pH — then adds it to your livestock in one tap.
Sign in to check my tanksGuides and lists that mention the otocinclus
- Bristlenose pleco vs otocinclus: which should you choose?
- How often should you feed aquarium fish?
- Why are my fish dying? A step-by-step checklist
- Amano shrimp vs cherry shrimp: which should you choose?
- Neon tetra vs cardinal tetra: which should you choose?
- Guppy vs molly: which should you choose?
- Fish for a 60-litre (16-gallon) aquarium
- Check the otocinclus with your other fish in the stocking checker
