Can Bucktooth Tetra (Exodon) and Julii Corydoras (False Julii) Live Together?

Bucktooth Tetra (Exodon) is a highly aggressive species (9/10), while Julii Corydoras (False Julii) is peaceful (0/10). This notable difference means Bucktooth Tetra (Exodon) may occasionally assert dominance over Julii Corydoras (False Julii).

Large aggression gap (9 points) between Bucktooth Tetra (Exodon) and Julii Corydoras (False Julii) increases stress risk for the more peaceful fish.

In terms of spatial distribution, Bucktooth Tetra (Exodon) prefers the Middle (Open Water) and Top (Surface) zones, whereas Julii Corydoras (False Julii) 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.

Worth noting: Bucktooth Tetra (Exodon) is a known jumper, so a tight-fitting lid is essential.

To improve the chances of a peaceful coexistence in this community tank: A larger aquarium with ample hiding spots can help diffuse aggression and give the less dominant fish space to retreat. Keep fin nippers in larger groups to distribute nipping behaviour among conspecifics rather than tank mates.

The safe temperature window for both species falls between 23°C and 26°C. Aim for the midpoint of this range (around 24.5°C) for optimal comfort.

Both fish can tolerate a pH between 6 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 2–15 dGH. Regular testing will ensure conditions stay within this range. An aquarium test kit is recommended for monitoring.

To house Bucktooth Tetra (Exodon) and Julii Corydoras (False Julii) 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.

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: Driftwood (Digestion/Hiding), Sand (Sifters). 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.