Can Assassin Snail and Jack Dempsey Live Together?

🔴Not Recommended

Assassin Snail and Jack Dempsey 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

Assassin Snail

Clea helena

Jack Dempsey

Rocio octofasciata

🐠Family Group
Assassin Snail
Invertebrates
Jack Dempsey
Cichlids - Central American
Temperament
Assassin Snail
Peaceful (2/10)
Jack Dempsey
Aggressive (8/10)
Temperature
✓ Compatible
Assassin Snail
22–28°C
Jack Dempsey
22–30°C
pH Range
✓ Compatible
Assassin Snail
7–8
Jack Dempsey
6.5–8
Hardness (dGH)
✓ Compatible
Assassin Snail
8–15
Jack Dempsey
5–15
Water Type
✓ Compatible
Assassin Snail
Freshwater Only
Jack Dempsey
Freshwater Only
Flow Preference
✓ Compatible
Assassin Snail
Low
Jack Dempsey
Moderate
Min Tank Volume
Combined: 240 L
Assassin Snail
10 L
Jack Dempsey
200 L
Swimming Level
Shared: 1 zone
Assassin Snail
Bottom
Jack Dempsey
MiddleBottom
🏷️Behavior Tags
Assassin Snail
Nano / Bite-sized (Predation Risk)Snail EaterDigger (Disturbs Substrate)
Jack Dempsey
Generally AggressiveAggressive to same species/look-alikesTerritorial (Defends specific area)Piscivore (Eats small/nano fish)Digger (Disturbs Substrate)Plant Destroyer

Behaviour & Temperament

Assassin Snail is a peaceful species (2/10), while Jack Dempsey is semi-aggressive (8/10). This notable difference means Jack Dempsey may occasionally assert dominance over Assassin Snail.

Large aggression gap (6 points) between Assassin Snail and Jack Dempsey increases stress risk for the more peaceful fish.

Assassin Snail and Jack Dempsey both frequent the 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 Nano / Bite-sized (Predation Risk) behaviour of one fish directly conflicts with the Piscivore (Eats small/nano fish) trait of the other — piscivorous fish will prey on nano-sized tank mates..

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 8. 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 Jack Dempsey together, plan for an aquarium of at least 240 litres with a minimum length of 120 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: Sand (Sifters), Driftwood (Digestion/Hiding), 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.

Frequently Asked Questions

Can Assassin Snail and Jack Dempsey live together?

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

What size tank do Assassin Snail and Jack Dempsey need?

A minimum of 240 litres (tank length at least 120 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 Jack Dempsey 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 Jack Dempsey aggressive?

Assassin Snail is peaceful (2/10) and Jack Dempsey is semi-aggressive (8/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Assassin Snail and Jack Dempsey need?

Both species overlap in the 7–8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

How do I manage Jack Dempsey's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Jack Dempsey 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.


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