Can Masked Julie (Julidochromis) and Pygmy Corydoras Live Together?

Masked Julie (Julidochromis) is a moderately assertive species (6/10), while Pygmy Corydoras is peaceful (0/10). This notable difference means Masked Julie (Julidochromis) may occasionally assert dominance over Pygmy Corydoras.

Large aggression gap (6 points) between Masked Julie (Julidochromis) and Pygmy Corydoras increases stress risk for the more peaceful fish.

Masked Julie (Julidochromis) and Pygmy Corydoras both frequent the Bottom (Substrate) and Middle (Open Water) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

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

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.

The pH requirements of Masked Julie (Julidochromis) (8–9) and Pygmy Corydoras (6–7.5) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–15 dGH. Regular testing will ensure conditions stay within this range. An aquarium test kit is recommended for monitoring.

To house Masked Julie (Julidochromis) and Pygmy Corydoras together, plan for an aquarium of at least 72 litres with a minimum length of 60 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), Plants - Densely covered. 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.