Can Flyspeck Hardyhead and Freshwater Shark (Wallago) Live Together?

Possible with Caution

Keeping Flyspeck Hardyhead and Freshwater Shark (Wallago) together is possible but requires caution due to differing aggression levels. Provide a spacious tank of at least 5500 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Flyspeck Hardyhead

Craterocephalus stercusmuscarum

Freshwater Shark (Wallago)

Wallago attu

🐠Family Group
Flyspeck Hardyhead
Other
Freshwater Shark (Wallago)
Catfish
Temperament
Flyspeck Hardyhead
Peaceful (1/10)
Freshwater Shark (Wallago)
Highly Aggressive (10/10)
Temperature
✓ Compatible
Flyspeck Hardyhead
22–28°C
Freshwater Shark (Wallago)
19–29°C
pH Range
✓ Compatible
Flyspeck Hardyhead
6–8
Freshwater Shark (Wallago)
6–7.6
Hardness (dGH)
✓ Compatible
Flyspeck Hardyhead
5–15
Freshwater Shark (Wallago)
1–20
Water Type
✓ Compatible
Flyspeck Hardyhead
Freshwater Only
Freshwater Shark (Wallago)
Freshwater Only
Flow Preference
✓ Compatible
Flyspeck Hardyhead
Moderate
Freshwater Shark (Wallago)
Moderate
Min Tank Volume
Combined: 5500 L
Flyspeck Hardyhead
75 L
Freshwater Shark (Wallago)
5500 L
Swimming Level
Shared: 1 zone
Flyspeck Hardyhead
TopMiddle
Freshwater Shark (Wallago)
MiddleBottom
🏷️Behavior Tags
Flyspeck Hardyhead
Hyperactive / Fast SwimmerJumper (Lid Required)
Freshwater Shark (Wallago)
Piscivore (Eats small/nano fish)Generally AggressiveAggressive to same species/look-alikesJumper (Lid Required)Hyperactive / Fast Swimmer
Stocking calculator

Can your tank handle Flyspeck Hardyhead and Freshwater Shark (Wallago)?

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.

Flyspeck Hardyhead
Freshwater Shark (Wallago)
Test both in my tank

Behaviour & Temperament

Flyspeck Hardyhead is a peaceful species (1/10), while Freshwater Shark (Wallago) is highly aggressive (10/10). This notable difference means Freshwater Shark (Wallago) may occasionally assert dominance over Flyspeck Hardyhead.

Large aggression gap (9 points) between Flyspeck Hardyhead and Freshwater Shark (Wallago) increases stress risk for the more peaceful fish.

Flyspeck Hardyhead and Freshwater Shark (Wallago) 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: Flyspeck Hardyhead 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.

Water Parameters

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 and 7.6. 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 Flyspeck Hardyhead and Freshwater Shark (Wallago) together, plan for an aquarium of at least 5500 litres with a minimum length of 300 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 - Densely covered, Established Algae (Otocinclus), Sand (Sifters), Smooth Gravel (Sensitive Barbels). 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.

Frequently Asked Questions

Can Flyspeck Hardyhead and Freshwater Shark (Wallago) live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 5500 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Flyspeck Hardyhead and Freshwater Shark (Wallago) need?

A minimum of 5500 litres (tank length at least 300 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 Flyspeck Hardyhead and Freshwater Shark (Wallago) together?

Keep the aquarium between 22°C and 28°C. A target of around 25.0°C sits comfortably within both species' preferred ranges.

Are Flyspeck Hardyhead or Freshwater Shark (Wallago) aggressive?

Flyspeck Hardyhead is peaceful (1/10) and Freshwater Shark (Wallago) is highly aggressive (10/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Flyspeck Hardyhead and Freshwater Shark (Wallago) need?

Both species overlap in the 6–7.6 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.


Related Comparisons

Flyspeck Hardyhead & Amazon Leaf Fish

·

Possible with Caution
Flyspeck Hardyhead: PeacefulAmazon Leaf Fish: Peaceful

Flyspeck Hardyhead & Australian Smelt

·

Possible with Caution
Flyspeck Hardyhead: PeacefulAustralian Smelt: Peaceful

Flyspeck Hardyhead & African Dwarf Frog

·

Possible with Caution
Flyspeck Hardyhead: PeacefulAfrican Dwarf Frog: Peaceful

Flyspeck Hardyhead & Largemouth Bass

·

Possible with Caution
Flyspeck Hardyhead: PeacefulLargemouth Bass: Peaceful

Flyspeck Hardyhead & Scarlet Badis

·

Possible with Caution
Flyspeck Hardyhead: PeacefulScarlet Badis: Peaceful

Flyspeck Hardyhead & African Clawed Frog

·

Possible with Caution
Flyspeck Hardyhead: PeacefulAfrican Clawed Frog: Peaceful

Freshwater Shark (Wallago) & Asian Upside Down Catfish

·

Possible with Caution
Freshwater Shark (Wallago): PeacefulAsian Upside Down Catfish: Peaceful

Freshwater Shark (Wallago) & Chao Phraya Giant Catfish (Paroon Shark)

·

Possible with Caution
Freshwater Shark (Wallago): PeacefulChao Phraya Giant Catfish (Paroon Shark): Peaceful

Freshwater Shark (Wallago) & Wels Catfish (European Catfish)

·

Possible with Caution
Freshwater Shark (Wallago): PeacefulWels Catfish (European Catfish): Peaceful

Freshwater Shark (Wallago) & Adonis Pleco

·

Possible with Caution
Freshwater Shark (Wallago): PeacefulAdonis Pleco: Peaceful

Freshwater Shark (Wallago) & Bullseye Catfish

·

Possible with Caution
Freshwater Shark (Wallago): PeacefulBullseye Catfish: Peaceful

Freshwater Shark (Wallago) & Channel Catfish

·

Possible with Caution
Freshwater Shark (Wallago): PeacefulChannel Catfish: Peaceful