Common otocinclus

Otocinclus vittatus

Also known as Common oto, Dwarf sucker

FreshwaterFish

Common otocinclus (Otocinclus vittatus) — No machine-readable author provided. Chle assumed (based on copyright claims). · CC BY-SA 3.0

Care at a glance

Temperature: 72–79°F (22–26°C)
pH: 6.0–7.5
Adult size: 2 in (5 cm)
Minimum tank: 20 gal (75 L)
Temperament: Peaceful
Social behavior: Schooling
Swim level: Bottom
Difficulty: Medium
Breeding: Hard
Rarity: Common
Origin: Amazon basin
Family: Loricariidae

Overview

Keep them in a group of at least six, in a tank of 75 liters or larger. They are peaceful algae grazers that work the bottom and the lower surfaces, picking at biofilm all day long. Water should sit between 22 and 26 C with a pH from 6 to 7.5, and the tank needs to be mature with real algae to graze before they go in. Supplement that with algae wafers and blanched vegetables like zucchini or cucumber, since bare glass won't keep them fed. They are completely shrimp safe and do well with other small, peaceful fish, so skip anything large or pushy.

In the wild

Common otocinclus come from the Amazon basin, where they cling to plants, wood, and rock in slow stretches of river and graze the algae and biofilm that coat every surface. To match that, give them a mature, well established tank that has had time to grow real algae, with a smooth substrate so they don't scrape their bellies. Keep the water between 22 and 26 C with a pH from 6 to 7.5. A tank that is too clean and new will starve them, so let it age before you add a group.

Good to know

This is a tiny suckermouth catfish in the family Loricariidae, topping out around 5 cm. Breeding is hard in the home tank, with eggs laid on leaves and glass and no parental care once they are placed. Most fish in the trade are still wild caught, which is part of why they ship poorly. A settled adult can live a few years.

Did you know

Otocinclus can breathe air through a modified gut, gulping at the surface and passing the bubble through to pull out oxygen. It is a backup system for the low oxygen, slow water they sometimes end up in. If you see one dash up for a quick gulp now and then, that is normal and not a sign of trouble on its own.