Can Cigar Shark (Mad Barb) and Freshwater Harlequin Shrimp (Sulawesi) Live Together?

Cigar Shark (Mad Barb) is a generally mild-mannered species (4/10), while Freshwater Harlequin Shrimp (Sulawesi) is peaceful (0/10). This notable difference means Cigar Shark (Mad Barb) may occasionally assert dominance over Freshwater Harlequin Shrimp (Sulawesi).

In terms of spatial distribution, Cigar Shark (Mad Barb) prefers the Middle (Open Water) and Top (Surface) zones, whereas Freshwater Harlequin Shrimp (Sulawesi) 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 Piscivore (Eats small/nano fish) behaviour of one fish directly conflicts with the Nano / Bite-sized (Predation Risk) trait of the other — piscivorous fish will prey on nano-sized tank mates..

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion. Aggressive eaters may outcompete shy fish for food, leading to malnutrition.

Worth noting: Freshwater Harlequin Shrimp (Sulawesi) is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Cigar Shark (Mad Barb) is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 26°C and 28°C. Aim for the midpoint of this range (around 27.0°C) for optimal comfort.

Both fish can tolerate a pH between 7.5 and 8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 4–8 dGH. Regular testing will ensure conditions stay within this range.

To house Cigar Shark (Mad Barb) and Freshwater Harlequin Shrimp (Sulawesi) together, plan for an aquarium of at least 1000 litres with a minimum length of 240 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

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), Established Algae (Otocinclus). Meeting these requirements will help both species thrive.

Cigar Shark (Mad Barb) prefers High (River/Stream) flow while Freshwater Harlequin Shrimp (Sulawesi) needs Low (Still Water) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.

Cigar Shark (Mad Barb) and Freshwater Harlequin Shrimp (Sulawesi) are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.

Feeding time deserves special attention with this pairing. Cigar Shark (Mad Barb) is an aggressive eater that may prevent Freshwater Harlequin Shrimp (Sulawesi) from getting enough food.

Because Cigar Shark (Mad Barb) is a fast, competitive feeder, consider using sinking pellets or feeding at opposite ends of the setup to ensure Freshwater Harlequin Shrimp (Sulawesi) receives an adequate share.