Water parameters
Overview
The golden otocinclus is a small species from the coastal streams of the Brazilian states of Rio de Janeiro and São Paulo. The name O. affinis is used very often in the trade, but most fish sold under this name are actually O. vittatus, O. macrospilus or other species. The true O. affinis is rarely imported.
Its most important difference is its temperature requirement: because it comes from the cool coastal streams of southeastern Brazil, it needs water cooler than a tropical aquarium, at 20–24°C. Adults grow to 4–5 cm.
Tank Setup
- At least 60 liters for a group of 6.
- A mature, planted aquarium with established biofilm.
- 20–24°C; it should not be kept at high temperatures for long periods.
Diet
Biofilm and fine algae are its main food; it should be supplemented with blanched zucchini, spirulina tablets and algae-based gel foods. Check the belly line of new arrivals; a sunken belly is a sign of starvation.
Behavior and Compatibility
Peaceful and timid; it feels safe in a group.
Good companions: Small fish that like cool to temperate water: White Cloud Mountain minnows, zebra danios, small barbs, dwarf shrimp.
Avoid: Warm-water species such as discus, large and aggressive fish.
A short profile for this species
The Golden Otocinclus page has the basics, but the sections below have not been written yet. If you keep this species, write a section from your own experience; it will be published under your name after editor approval.
Tank mates
This list is calculated automatically from the species profile and grows as new species are added to the catalog. Try it in the planner for a definite answer.
Usually compatible
Flame Tetra
Blackfin Corydoras
Polystictus Corydoras
Emerald Cory
Emerald Dwarf Rasbora
Porthole Catfish
Keyhole Cichlid
Cryptocoryne Parva
European Bitterling
Adolfo's Cory
Should not be kept together
Hobbyist notes
Things you won't find in books, learned by trial and error. The most helpful ones are on top.
Change history and contributors
- Page created · October 16, 2026