Can Otocinclus and Uaru Live Together?

🔴Not Recommended

Otocinclus and Uaru are not recommended as tank mates due to no temperature overlap. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Otocinclus

Otocinclus vittatus

Uaru

Uaru amphiacanthoides

🐠Family Group
Otocinclus
Catfish
Uaru
Cichlids - South American
Temperament
Otocinclus
Peaceful (0/10)
Uaru
Mostly Peaceful (4/10)
Temperature
✗ No overlap
Otocinclus
21–26°C
Uaru
27–30°C
pH Range
✓ Compatible
Otocinclus
6–7.5
Uaru
5–7
Hardness (dGH)
✓ Compatible
Otocinclus
4–15
Uaru
1–8
Water Type
✓ Compatible
Otocinclus
Freshwater Only
Uaru
Freshwater Only
Flow Preference
✓ Compatible
Otocinclus
Moderate
Uaru
Low
Min Tank Volume
Combined: 480 L
Otocinclus
38 L
Uaru
400 L
Swimming Level
Shared: 2 zones
Otocinclus
MiddleBottom
Uaru
MiddleBottom
🏷️Behavior Tags
Otocinclus
Nano / Bite-sized (Predation Risk)Shy / Slow Moving (Easily Stressed)
Uaru
Plant DestroyerShy / Slow Moving (Easily Stressed)Shrimp Eater

Behaviour & Temperament

Otocinclus is a peaceful species (0/10), while Uaru is generally mild-mannered (4/10). This notable difference means Uaru may occasionally assert dominance over Otocinclus.

Otocinclus and Uaru both frequent the Middle (Open Water) and Bottom (Substrate) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

Additional behavioural considerations to keep in mind: Shrimp eaters may also prey on very small nano fish.

Water Parameters

There is no temperature overlap between Otocinclus (21–26°C) and Uaru (27–30°C). This fundamental mismatch makes long-term cohabitation impractical.

Both fish can tolerate a pH between 6 and 7. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 4–8 dGH. Regular testing will ensure conditions stay within this range. An aquarium test kit is recommended for monitoring.

Tank Setup

To house Otocinclus and Uaru together, plan for an aquarium of at least 480 litres with a minimum length of 150 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

Providing a mix of open swimming space and sheltered areas with rocks, driftwood, or plants will keep both species comfortable and allow natural behaviour.

Specific environmental needs for this combination include: Established Algae (Otocinclus), Plants - Densely covered, Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/Hiding), Sand (Sifters). Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Uaru is a plant destroyer, which conflicts with Otocinclus's requirement for live plants. Compromise where possible or prioritise the more critical need.

Both species do well with moderate (standard) water movement, so a standard filtration setup rated for the tank volume should suffice.

Find the right tank equipment

Browse tanks, décor, and equipment suited for this setup.

Diet & Feeding

Feeding time deserves special attention with this pairing. Uaru is a known shrimp eater and may prey on small invertebrates or nano fish like Otocinclus.

Frequently Asked Questions

Can Otocinclus and Uaru live together?

No. This combination is not recommended. Key incompatibilities — such as non-overlapping temperature ranges — make cohabitation unsafe.

What size tank do Otocinclus and Uaru need?

A minimum of 480 litres (tank length at least 150 cm) is recommended. This provides enough space for both species to establish their own areas and reduces the likelihood of territorial disputes.

What water temperature is best for Otocinclus and Uaru together?

Unfortunately, there is no temperature range that satisfies both species. Otocinclus requires 21–26°C, while Uaru needs 27–30°C.

Are Otocinclus or Uaru aggressive?

Otocinclus is peaceful (0/10) and Uaru is generally mild-mannered (4/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Otocinclus and Uaru need?

Both species overlap in the 6–7 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.


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