Can Assassin Snail and Gertrude's Spotted Blue-eye Live Together?

Reviewed by Guidarium Editorial DeskUpdated April 28, 2026
Ideal Tank Mates

Yes, Assassin Snail and Gertrude's Spotted Blue-eye are ideal tank mates. Both species share compatible water parameters and peaceful temperaments, making them well-suited for a community aquarium. They occupy different areas of the water column, which reduces competition for space. A minimum tank size of 38 litres is recommended.


At a Glance

Assassin Snail

Anentome helena

Gertrude's Spotted Blue-eye

Pseudomugil gertrudae

🐠Family Group
Assassin Snail
Invertebrates
Gertrude's Spotted Blue-eye
Rainbowfish
Temperament
Assassin Snail
Peaceful (2/10)
Gertrude's Spotted Blue-eye
Peaceful (2/10)
Temperature
✓ Compatible
Assassin Snail
22–28°C
Gertrude's Spotted Blue-eye
21–28°C
pH Range
✓ Compatible
Assassin Snail
7–8
Gertrude's Spotted Blue-eye
6–7.5
Hardness (dGH)
✓ Compatible
Assassin Snail
8–15
Gertrude's Spotted Blue-eye
5–15
Water Type
✓ Compatible
Assassin Snail
Freshwater Only
Gertrude's Spotted Blue-eye
Freshwater Only
Flow Preference
✓ Compatible
Assassin Snail
Low
Gertrude's Spotted Blue-eye
Moderate
Min Tank Volume
Combined: 38 L
Assassin Snail
10 L
Gertrude's Spotted Blue-eye
38 L
Swimming Level
✓ Different zones
Assassin Snail
Bottom
Gertrude's Spotted Blue-eye
TopMiddle
🏷️Behavior Tags
Assassin Snail
Nano / Bite-sized (Predation Risk)Snail EaterDigger (Disturbs Substrate)
Gertrude's Spotted Blue-eye
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerJumper (Lid Required)Fry Predator
Stocking calculator

Can your tank handle Assassin Snail and Gertrude's Spotted Blue-eye?

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.

Assassin Snail
Gertrude's Spotted Blue-eye
Test both in my tank

Behaviour & Temperament

Both Assassin Snail and Gertrude's Spotted Blue-eye are peaceful species with an aggression score of 2/10. Their matching temperaments mean neither fish is likely to dominate the other in a shared aquarium.

In terms of spatial distribution, Assassin Snail prefers the Bottom (Substrate) zone, whereas Gertrude's Spotted Blue-eye occupies the Top (Surface) and Middle (Open Water) zones. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

Worth noting: Gertrude's Spotted Blue-eye is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 22°C and 28°C. Aim for the midpoint of this range (around 25.0°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 8–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Assassin Snail and Gertrude's Spotted Blue-eye together, plan for an aquarium of at least 38 litres with a minimum length of 45 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: Sand (Sifters), Plants - Densely covered, Plants - Floating, Leaf Litter/Blackwater. 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 Works in Practice

Assassin Snail and Gertrude's Spotted Blue-eye work best when the tank gives each fish enough room to use its preferred level of the aquarium and enough cover to avoid constant visual contact. The score matters, but the real-world success usually comes from matching their pace, keeping water stable, and resisting the urge to crowd the tank just because the pair looks safe on paper.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Assassin Snail and Gertrude's Spotted Blue-eye.

Show 22 more tank sizes

Frequently Asked Questions

Can Assassin Snail and Gertrude's Spotted Blue-eye live together?

Yes. Assassin Snail and Gertrude's Spotted Blue-eye are considered ideal tank mates. Their water parameters, temperaments, and behaviour profiles are well matched for a community aquarium.

What size tank do Assassin Snail and Gertrude's Spotted Blue-eye need?

A minimum of 38 litres (tank length at least 45 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 Assassin Snail and Gertrude's Spotted Blue-eye together?

Keep the aquarium between 22°C and 28°C. A target of around 25.0°C sits comfortably within both species' preferred ranges.

Are Assassin Snail or Gertrude's Spotted Blue-eye aggressive?

Assassin Snail is peaceful (2/10) and Gertrude's Spotted Blue-eye is peaceful (2/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Assassin Snail and Gertrude's Spotted Blue-eye 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.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
April 28, 2026
Last updated
April 28, 2026
Issues or corrections?
Contact the editorial team

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