Can Siamese Tiger Fish and X-Ray Tetra (Pristella) Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Not Recommended

Siamese Tiger Fish and X-Ray Tetra (Pristella) are not recommended as tank mates due to piscivorous fish will prey on nano-sized tank mates.. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Siamese Tiger Fish

Datnioides pulcher

X-Ray Tetra (Pristella)

Pristella maxillaris

🐠Family Group
Siamese Tiger Fish
Oddballs
X-Ray Tetra (Pristella)
Characins
Temperament
Siamese Tiger Fish
Semi-Aggressive (6/10)
X-Ray Tetra (Pristella)
Peaceful (1/10)
Temperature
✓ Compatible
Siamese Tiger Fish
24–28°C
X-Ray Tetra (Pristella)
23–28°C
pH Range
✓ Compatible
Siamese Tiger Fish
6.5–7.5
X-Ray Tetra (Pristella)
6–8
Hardness (dGH)
✓ Compatible
Siamese Tiger Fish
5–15
X-Ray Tetra (Pristella)
2–20
Water Type
✓ Compatible
Siamese Tiger Fish
Freshwater Only
X-Ray Tetra (Pristella)
Brackish Tolerant
Flow Preference
✓ Compatible
Siamese Tiger Fish
Moderate
X-Ray Tetra (Pristella)
Moderate
Min Tank Volume
Combined: 680 L
Siamese Tiger Fish
680 L
X-Ray Tetra (Pristella)
60 L
Swimming Level
Shared: 2 zones
Siamese Tiger Fish
MiddleBottom
X-Ray Tetra (Pristella)
MiddleBottom
🏷️Behavior Tags
Siamese Tiger Fish
Piscivore (Eats small/nano fish)Shrimp EaterFry PredatorShy / Slow Moving (Easily Stressed)Territorial (Defends specific area)
X-Ray Tetra (Pristella)
Hyperactive / Fast SwimmerNano / Bite-sized (Predation Risk)Fry Predator
Stocking calculator

Can your tank handle Siamese Tiger Fish and X-Ray Tetra (Pristella)?

Compatibility is only part of the answer. Test both fish with your real tank size, current stock, and maintenance needs to see if you have enough space and a safe stocking level before you add them.

Siamese Tiger Fish
X-Ray Tetra (Pristella)
Test both in my tank

Behaviour & Temperament

Siamese Tiger Fish is a moderately assertive species (6/10), while X-Ray Tetra (Pristella) is peaceful (1/10). This notable difference means Siamese Tiger Fish may occasionally assert dominance over X-Ray Tetra (Pristella).

Siamese Tiger Fish and X-Ray Tetra (Pristella) 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.

There is a critical concern: the Piscivore (Eats small/nano fish) behaviour of one fish directly conflicts with the Nano / Bite-sized (Predation Risk) trait of the other — piscivorous fish will prey on nano-sized tank mates..

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion. Shrimp eaters may also prey on very small nano fish.

Water Parameters

The safe temperature window for both species falls between 24°C and 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 5–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Siamese Tiger Fish and X-Ray Tetra (Pristella) together, plan for an aquarium of at least 680 litres with a minimum length of 180 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

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: Driftwood (Digestion/Hiding), Smooth Gravel (Sensitive Barbels), Plants - Densely covered. Meeting these requirements will help both species thrive.

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

Why This Pairing Usually Fails in Practice

Siamese Tiger Fish and X-Ray Tetra (Pristella) are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Siamese Tiger Fish and X-Ray Tetra (Pristella).

Diet & Feeding

Feeding time deserves special attention with this pairing. Siamese Tiger Fish is a known shrimp eater and may prey on small invertebrates or nano fish like X-Ray Tetra (Pristella).

Frequently Asked Questions

Can Siamese Tiger Fish and X-Ray Tetra (Pristella) live together?

No. This combination is not recommended. Key incompatibilities — such as critical behavioural conflicts — make cohabitation unsafe.

What size tank do Siamese Tiger Fish and X-Ray Tetra (Pristella) need?

A minimum of 680 litres (tank length at least 180 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 Siamese Tiger Fish and X-Ray Tetra (Pristella) together?

Keep the aquarium between 24°C and 28°C. A target of around 26.0°C sits comfortably within both species' preferred ranges.

Are Siamese Tiger Fish or X-Ray Tetra (Pristella) aggressive?

Siamese Tiger Fish is moderately assertive (6/10) and X-Ray Tetra (Pristella) is peaceful (1/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Siamese Tiger Fish and X-Ray Tetra (Pristella) need?

Both species overlap in the 6.5–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

How do I manage Siamese Tiger Fish's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Siamese Tiger Fish space to claim a territory without encroaching on the other fish's area. Adding décor that divides the tank into distinct zones works especially well.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 11, 2026
Last updated
May 11, 2026
Issues or corrections?
Contact the editorial team

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