Can Bucktooth Tetra (Exodon) and Violet Goby (Dragon Goby) Live Together?

Bucktooth Tetra (Exodon) is a highly aggressive species (9/10), while Violet Goby (Dragon Goby) is peaceful (2/10). This notable difference means Bucktooth Tetra (Exodon) may occasionally assert dominance over Violet Goby (Dragon Goby).

Large aggression gap (7 points) between Bucktooth Tetra (Exodon) and Violet Goby (Dragon Goby) 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 Violet Goby (Dragon Goby) 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.

There is a critical concern: the Eye Biter (Attacks slow moving fish) behaviour of one fish directly conflicts with the Shy / Slow Moving (Easily Stressed) trait of the other — eye biters attack slow-moving fish, risking permanent injury..

Additional behavioural considerations to keep in mind: Aggressive fish may bully and stress shy, slow-moving species. Hyperactive swimmers can stress shy, slow-moving species through constant motion.

Worth noting: Violet Goby (Dragon Goby) is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Bucktooth Tetra (Exodon) is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 23°C and 28°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.

Both fish can tolerate a pH between 7.5 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 12–15 dGH. Regular testing will ensure conditions stay within this range.

Crucially, these species require different water types — one needs freshwater while the other requires brackish conditions. This is a hard barrier to keeping them together. An aquarium test kit is recommended for monitoring.

To house Bucktooth Tetra (Exodon) and Violet Goby (Dragon Goby) 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: Driftwood (Digestion/Hiding), Sand (Sifters), Shells (Breeding/Hiding). 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.