Otocinclus Arnoldi (Otocinclus arnoldi)
Otocinclus Arnoldi is a small, peaceful South American algae-grazing catfish, also known as the La Plata Oto. Like other Otocinclus, it is best kept in a mature planted aquarium where it can graze naturally across plant leaves, wood, stones and glass. This is a gentle, social species that works well in calm community aquariums, but it should be treated as a specialist grazer rather than a simple “clean-up crew” fish, as it needs stable water quality and regular supplementary feeding.
Common Name
Otocinclus Arnoldi. Also commonly referred to as the La Plata Oto, Arnold’s Oto, Dwarf Suckermouth Catfish or Oto Catfish.
Scientific Name (Latin)
Otocinclus arnoldi
| Size | Temperature | Water pH | Water Hardness |
|---|---|---|---|
| 1.5 to 2.5 cm (0.6 to 1 inch) | 22–28°C (72–82°F) | 5.5–7.0 | 2–8 dGH |
FAQ
What kind of environment does Otocinclus Arnoldi require?
Otocinclus Arnoldi thrives in a mature planted aquarium with stable water conditions. It prefers environments with plant leaves, wood, stones, and glass for grazing. A calm, well-established tank with consistent water parameters is essential.
Can Otocinclus Arnoldi live with other fish?
Yes, it is a gentle and social species that works well in calm community aquariums. It should be kept with similarly peaceful fish that do not create strong currents or aggressive behavior.
What should I feed Otocinclus Arnoldi?
While it naturally grazes on algae, it requires regular supplementary feeding of high-quality sinking pellets or algae wafers to maintain health and growth.
Sebastian Simpson –
I’ve had my Otocinclus Arnoldi for six months now. It’s very active and always found algae on the glass and plant leaves. I feed it a bit of algae wafers every day and it stays healthy. The fish is peaceful and doesn’t stress other tank mates. Great addition to a planted tank.
Simon Parsons –
The fish is small but very interesting to watch. I noticed it spends time grazing on the back of the plants. I keep it with some peaceful tetras and it gets along well. I do have to feed it a bit more than I thought it would need.
Steven Ferguson –
Perfect for a beginner aquarist who wants a low-maintenance algae eater. It doesn’t chase other fish and stays calm. I’ve kept it in a 20-gallon tank with live plants and it’s been thriving. Only issue is it needs consistent feeding.