Can Dusky Millions Fish and Reticulated Stingray (Teacup Ray) Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Possible with Caution

Keeping Dusky Millions Fish and Reticulated Stingray (Teacup Ray) together is possible but requires caution, though some care is needed. Provide a spacious tank of at least 680 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Dusky Millions Fish

Phalloceros caudimaculatus

Reticulated Stingray (Teacup Ray)

Potamotrygon orbignyi

🐠Family Group
Dusky Millions Fish
Livebearers
Reticulated Stingray (Teacup Ray)
Oddballs
Temperament
Dusky Millions Fish
Peaceful (2/10)
Reticulated Stingray (Teacup Ray)
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Dusky Millions Fish
16–24°C
Reticulated Stingray (Teacup Ray)
24–30°C
pH Range
✓ Compatible
Dusky Millions Fish
7–8
Reticulated Stingray (Teacup Ray)
6–7.5
Hardness (dGH)
✓ Compatible
Dusky Millions Fish
8–20
Reticulated Stingray (Teacup Ray)
1–10
Water Type
✓ Compatible
Dusky Millions Fish
Brackish Tolerant
Reticulated Stingray (Teacup Ray)
Freshwater Only
Flow Preference
✓ Compatible
Dusky Millions Fish
Low
Reticulated Stingray (Teacup Ray)
Moderate
Min Tank Volume
Combined: 680 L
Dusky Millions Fish
40 L
Reticulated Stingray (Teacup Ray)
680 L
Swimming Level
✓ Different zones
Dusky Millions Fish
TopMiddle
Reticulated Stingray (Teacup Ray)
Bottom
🏷️Behavior Tags
Dusky Millions Fish
Hyperactive / Fast SwimmerPlant DestroyerFin Nipper
Reticulated Stingray (Teacup Ray)
Piscivore (Eats small/nano fish)Digger (Disturbs Substrate)Hyperactive / Fast SwimmerShrimp EaterSnail EaterFry Predator
Stocking calculator

Can your tank handle Dusky Millions Fish and Reticulated Stingray (Teacup Ray)?

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.

Dusky Millions Fish
Reticulated Stingray (Teacup Ray)
Test both in my tank

Behaviour & Temperament

Dusky Millions Fish is a peaceful species (2/10), while Reticulated Stingray (Teacup Ray) is generally mild-mannered (4/10). This modest difference means Reticulated Stingray (Teacup Ray) may occasionally assert dominance over Dusky Millions Fish.

In terms of spatial distribution, Dusky Millions Fish prefers the Top (Surface) and Middle (Open Water) zones, whereas Reticulated Stingray (Teacup Ray) occupies the Bottom (Substrate) zone. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

To improve the chances of a peaceful coexistence in this community tank: Keep fin nippers in larger groups to distribute nipping behaviour among conspecifics rather than tank mates.

Water Parameters

The safe temperature window for both species falls between 24°C and 24°C. Aim for the midpoint of this range (around 24.0°C) for optimal comfort.

Both fish can tolerate a pH between 7 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 8–10 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Dusky Millions Fish and Reticulated Stingray (Teacup Ray) 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.

Because this pairing requires extra vigilance, include plenty of hiding spots — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

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

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

Why This Pairing Needs Extra Planning in Practice

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Dusky Millions Fish and Reticulated Stingray (Teacup Ray) need extra room, more cover, and closer observation during the first few weeks so small aggression, feeding, or territory issues do not snowball into a long-term problem.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Dusky Millions Fish and Reticulated Stingray (Teacup Ray).

Frequently Asked Questions

Can Dusky Millions Fish and Reticulated Stingray (Teacup Ray) live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 680 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Dusky Millions Fish and Reticulated Stingray (Teacup Ray) 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 Dusky Millions Fish and Reticulated Stingray (Teacup Ray) together?

Keep the aquarium between 24°C and 24°C. A target of around 24.0°C sits comfortably within both species' preferred ranges.

Are Dusky Millions Fish or Reticulated Stingray (Teacup Ray) aggressive?

Dusky Millions Fish is peaceful (2/10) and Reticulated Stingray (Teacup Ray) is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Dusky Millions Fish and Reticulated Stingray (Teacup Ray) need?

Both species overlap in the 7–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Dusky Millions Fish nip Reticulated Stingray (Teacup Ray)'s fins?

Dusky Millions Fish is a known fin nipper. If Reticulated Stingray (Teacup Ray) has long or flowing fins, there is a real risk of fin damage. Keeping Dusky Millions Fish in a larger group can help redirect nipping behaviour toward conspecifics.

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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