Can Assassin Snail and Gardner's Killifish Live Together?

Assassin Snail is a peaceful species (2/10), while Gardner's Killifish is generally mild-mannered (4/10). This modest difference means Gardner's Killifish may occasionally assert dominance over Assassin Snail.

In terms of spatial distribution, Assassin Snail prefers the Bottom (Substrate) zone, whereas Gardner's Killifish 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.

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

Worth noting: Gardner's Killifish is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 22°C and 26°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. An aquarium test kit is recommended for monitoring.

To house Assassin Snail and Gardner's Killifish together, plan for an aquarium of at least 46 litres with a minimum length of 45 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

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: Sand (Sifters), Plants - Densely covered, Plants - Floating, Plants - lighly covered. 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.

Feeding time deserves special attention with this pairing. Gardner's Killifish is a known shrimp eater and may prey on small invertebrates or nano fish like Assassin Snail.