Beginner
Bristlenose Pleco (Ancistrus sp.)
23–29°C · pH 6–7.5 · 80L
From £3.51Some sizes on sale
Golden Otocinclus (Otocinclus sp.) is a peaceful social grazer for mature planted aquariums. Keep 6+ in about 60L or larger and supplement biofilm with suitable sinking foods.
Otocinclus sp.
Golden Otocinclus are a shoaling species — they need 6+ to feel safe and show their full colour.
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Golden Otocinclus (Otocinclus sp.) is a peaceful social grazer for mature planted aquariums. Keep 6+ in about 60L or larger and supplement biofilm with suitable sinking foods.
23–29°C · pH 6–7.5 · 80L
24–27°C · pH 6–7.5 · 80L
22–27°C · pH 6–8 · 80L
18–26°C · pH 6.5–8 · 30L
A practical guide to Otocinclus setup, feeding, group care and tank mates, with an emphasis on mature planted aquariums and established grazing surfaces.
Maintain these water conditions for optimal health and vibrant colors
Golden Otocinclus is the supplier trade name for this small, peaceful Otocinclus-type catfish. The available batch and image evidence does not distinguish Otocinclus affinis from the more commonly traded O. vittatus with enough confidence, so the scientifically honest identification is Otocinclus sp. Golden Oto and dwarf suckermouth catfish are other useful aquarium-trade names.
These fish are social biofilm and algae grazers for a mature planted aquarium. They should be chosen for their natural grazing behaviour rather than treated as a substitute for aquarium maintenance or as a quick solution for a new tank.
What you receive: one unsexed fish from the selected size option. The selected sale size is not its adult size. Colour, body shape, lateral markings and exact species can vary between fish and batches.
| Scientific identification | Otocinclus sp. |
|---|---|
| Trade names | Golden Otocinclus; Golden Oto; dwarf suckermouth catfish |
| Expected adult size | Approximately 3.5–5 cm, depending on the supplied species |
| Minimum aquarium | A mature, planted aquarium of at least 60 litres with ample grazing area |
| Group size | Keep 6 or more together |
| Temperature | 22–26°C |
| pH | 6.0–7.5 |
| Care level | Moderate |
| Temperament | Peaceful and social |
| Diet | Biofilm and soft-algae grazer that also needs supplementary food |
A fully cycled tank can still be too biologically immature for Otocinclus. Add a group only after the aquarium has matured and developed stable biofilm across plenty of safe grazing surfaces. Live plants, smooth wood, rounded stone and broad leaves provide useful feeding areas, while shaded retreats help newly introduced fish settle. If you are preparing a new setup, start with the aquarium nitrogen cycle guide.
Keep ammonia and nitrite at zero, control nitrate with sensible stocking and regular partial water changes, and maintain good oxygenation through surface movement and gentle to moderate flow. Stability is more important than repeatedly adjusting the aquarium to reach one exact reading. Avoid sharp decor and sudden changes in temperature or water chemistry; our water chemistry guide explains the main measurements.
Natural soft algae and biofilm are important, but they may not feed a group throughout the year. Supplement with good-quality sinking algae wafers or herbivore foods and small portions of aquarium-safe blanched vegetables. Remove uneaten vegetables before they spoil the water.
Watch every fish at feeding time because fast community fish can take prepared food first. Offering a suitable sinking food when the main lights dim may help, but it does not replace mature grazing surfaces. A well-fed fish should develop a gently rounded belly; a pinched or hollow abdomen can indicate poor intake and needs prompt attention.
Before ordering, look for established soft growth and biofilm on wood, plant leaves, stone and glass rather than relying only on the aquarium’s age. Confirm zero ammonia and nitrite, dependable oxygenation, a plan for a group of at least six and a quiet place where sinking food can reach them. A tank can be technically cycled yet still be too clean or biologically young to support newly introduced Otocinclus.
Otocinclus commonly browse soft green or brown surface films, diatoms and the microorganisms within biofilm. They should not be purchased with a promise that they will clear long hair algae, black beard algae or hard green spot algae. Even when visible algae is present, monitor each fish’s belly and continue offering suitable supplementary food; natural growth can decline quickly or be taken first by other grazers.
Keep at least six together so these peaceful catfish can settle and graze socially. Suitable companions include small peaceful tetras, rasboras, Cory-type catfish and other calm fish that share the same water requirements and will not monopolise food.
Avoid large predators, aggressive territorial species, very boisterous feeders and heavy competition from numerous larger algae grazers. Always compare the adult size, behaviour and water needs of every companion rather than relying only on a broad “community fish” label.
For other Otocinclus-type fish, compare the Zebra Oto and Otocinclus flexilis listings. Their identity, care needs and availability should be assessed separately.
Otocinclus can arrive thin or struggle after abrupt environmental changes, so body condition and early feeding deserve close attention. Prepare the mature aquarium before ordering, match temperature carefully and follow the supplied acclimation guidance without leaving the fish in transport water longer than necessary. Monitor the whole group during the first days and confirm that each fish grazes and accepts supplementary food.
Each quantity is one unsexed fish from the selected size option. Eligible livestock orders are covered by the Tropical Fish Co delivery and Live Arrival Guarantee. Review the published delivery and evidence conditions in advance, and keep the arrival and returns instructions available for delivery day.
Most lifestyle images in the gallery are representative Otocinclus-type illustrations rather than photographs of the exact fish dispatched. A real Otocinclus reference photograph is also included, but it does not prove the identity or appearance of the supplied batch. No gallery image guarantees the exact species, a fixed golden colour, sex, markings, size or condition of the fish you receive.
