Can Iridescent Shark and Royal Pleco (L190) Live Together?

Iridescent Shark is a generally mild-mannered species (3/10), while Royal Pleco (L190) is moderately assertive (5/10). This modest difference means Royal Pleco (L190) may occasionally assert dominance over Iridescent Shark.

In terms of spatial distribution, Iridescent Shark prefers the Middle (Open Water) zone, whereas Royal Pleco (L190) 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: Royal Pleco (L190) is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Iridescent Shark is a known jumper, so a tight-fitting lid is essential.

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 6.5 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 5–15 dGH. Regular testing will ensure conditions stay within this range. An aquarium test kit is recommended for monitoring.

To house Iridescent Shark and Royal Pleco (L190) together, plan for an aquarium of at least 2400 litres with a minimum length of 250 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: Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/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.