Can Flagtail Prochilodus and Shortnose Gar Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Possible with Caution

Keeping Flagtail Prochilodus and Shortnose Gar together is possible but requires caution due to mismatched flow preferences. Provide a spacious tank of at least 1000 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Flagtail Prochilodus

Semaprochilodus insignis

Shortnose Gar

Lepisosteus platostomus

🐠Family Group
Flagtail Prochilodus
Characins
Shortnose Gar
Oddballs
Temperament
Flagtail Prochilodus
Semi-Aggressive (6/10)
Shortnose Gar
Aggressive (7/10)
Temperature
✓ Compatible
Flagtail Prochilodus
23–28°C
Shortnose Gar
10–28°C
pH Range
✓ Compatible
Flagtail Prochilodus
5.5–7.5
Shortnose Gar
6–8
Hardness (dGH)
✓ Compatible
Flagtail Prochilodus
2–15
Shortnose Gar
5–20
Water Type
✓ Compatible
Flagtail Prochilodus
Freshwater Only
Shortnose Gar
Freshwater Only
Flow Preference
✗ No overlap
Flagtail Prochilodus
High
Shortnose Gar
Low
Min Tank Volume
Combined: 1000 L
Flagtail Prochilodus
500 L
Shortnose Gar
1000 L
Swimming Level
Shared: 1 zone
Flagtail Prochilodus
MiddleBottom
Shortnose Gar
TopMiddle
🏷️Behavior Tags
Flagtail Prochilodus
Plant DestroyerHyperactive / Fast SwimmerJumper (Lid Required)Aggressive to same species/look-alikes
Shortnose Gar
Piscivore (Eats small/nano fish)Jumper (Lid Required)Hyperactive / Fast Swimmer
Stocking calculator

Can your tank handle Flagtail Prochilodus and Shortnose Gar?

Compatibility is only part of the answer. Test both fish with your real tank size, current stock, and maintenance needs to see if you have enough space and a safe stocking level before you add them.

Flagtail Prochilodus
Shortnose Gar
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Behaviour & Temperament

Flagtail Prochilodus is a moderately assertive species (6/10), while Shortnose Gar is semi-aggressive (7/10). This modest difference means Shortnose Gar may occasionally assert dominance over Flagtail Prochilodus.

Flagtail Prochilodus and Shortnose Gar 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: Flagtail Prochilodus is a known jumper, so a tight-fitting lid is essential.

Water Parameters

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 6 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.

Tank Setup

To house Flagtail Prochilodus and Shortnose Gar 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.

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: Established Algae (Otocinclus), Driftwood (Digestion/Hiding), Sand (Sifters), Smooth Gravel (Sensitive Barbels). Meeting these requirements will help both species thrive.

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

Why This Pairing Needs Extra Planning in Practice

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Flagtail Prochilodus and Shortnose Gar 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.

Frequently Asked Questions

Can Flagtail Prochilodus and Shortnose Gar live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 1000 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Flagtail Prochilodus and Shortnose Gar need?

A minimum of 1000 litres (tank length at least 240 cm) is recommended. This provides enough space for both species to establish their own areas and reduces the likelihood of territorial disputes.

What water temperature is best for Flagtail Prochilodus and Shortnose Gar together?

Keep the aquarium between 23°C and 28°C. A target of around 25.5°C sits comfortably within both species' preferred ranges.

Are Flagtail Prochilodus or Shortnose Gar aggressive?

Flagtail Prochilodus is moderately assertive (6/10) and Shortnose Gar is semi-aggressive (7/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Flagtail Prochilodus and Shortnose Gar need?

Both species overlap in the 6–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 11, 2026
Last updated
May 11, 2026
Issues or corrections?
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