Can Longnose Gar and Riffle Shrimp Live Together?

Longnose Gar is a semi-aggressive species (7/10), while Riffle Shrimp is peaceful (0/10). This notable difference means Longnose Gar may occasionally assert dominance over Riffle Shrimp.

Large aggression gap (7 points) between Longnose Gar and Riffle Shrimp increases stress risk for the more peaceful fish.

Longnose Gar and Riffle Shrimp both frequent the 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.

Worth noting: Longnose Gar 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.

The safe temperature window for both species falls between 17°C and 25°C. Aim for the midpoint of this range (around 21.0°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 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 8–15 dGH. Regular testing will ensure conditions stay within this range.

To house Longnose Gar and Riffle Shrimp together, plan for an aquarium of at least 4000 litres with a minimum length of 360 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

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: Plants - Floating, Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/Hiding). Meeting these requirements will help both species thrive.

Longnose Gar prefers Low (Still Water) flow while Riffle Shrimp needs High (River/Stream) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Longnose Gar and Riffle Shrimp need extra room, more cover, and closer observation during the first few weeks so small aggression, feeding, or territory issues do not snowball into a long-term problem.