Can Marlier's Julie and Wolf Fish Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Not Recommended

Marlier's Julie and Wolf Fish are not recommended as tank mates due to conflicting pH requirements. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Marlier's Julie

Julidochromis marlieri

Wolf Fish

Hoplias malabaricus

🐠Family Group
Marlier's Julie
Cichlids - African
Wolf Fish
Oddballs
Temperament
Marlier's Julie
Semi-Aggressive (6/10)
Wolf Fish
Highly Aggressive (10/10)
Temperature
✓ Compatible
Marlier's Julie
23–27°C
Wolf Fish
22–28°C
pH Range
✗ No overlap
Marlier's Julie
8.2–9.3
Wolf Fish
6–8
Hardness (dGH)
✓ Compatible
Marlier's Julie
10–25
Wolf Fish
2–15
Water Type
✓ Compatible
Marlier's Julie
Freshwater Only
Wolf Fish
Freshwater Only
Flow Preference
✓ Compatible
Marlier's Julie
Moderate
Wolf Fish
Low
Min Tank Volume
Combined: 450 L
Marlier's Julie
114 L
Wolf Fish
450 L
Swimming Level
Shared: 2 zones
Marlier's Julie
BottomMiddle
Wolf Fish
MiddleBottom
🏷️Behavior Tags
Marlier's Julie
Territorial (Defends specific area)Aggressive to same species/look-alikesDigger (Disturbs Substrate)Fry Predator
Wolf Fish
Piscivore (Eats small/nano fish)Generally AggressiveAggressive to same species/look-alikesTerritorial (Defends specific area)Jumper (Lid Required)Shy / Slow Moving (Easily Stressed)Nocturnal
Stocking calculator

Can your tank handle Marlier's Julie and Wolf Fish?

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.

Marlier's Julie
Wolf Fish
Test both in my tank

Behaviour & Temperament

Marlier's Julie is a moderately assertive species (6/10), while Wolf Fish is highly aggressive (10/10). This notable difference means Wolf Fish may occasionally assert dominance over Marlier's Julie.

Marlier's Julie and Wolf Fish both frequent the Bottom (Substrate) and 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.

Additional behavioural considerations to keep in mind: Two territorial species may clash over territory, especially in smaller tanks.

Worth noting: Wolf Fish is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Wolf Fish 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 27°C. Aim for the midpoint of this range (around 25.0°C) for optimal comfort.

The pH requirements of Marlier's Julie (8.2–9.3) and Wolf Fish (6–8) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Marlier's Julie and Wolf Fish together, plan for an aquarium of at least 450 litres with a minimum length of 150 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: Sand (Sifters), Driftwood (Digestion/Hiding), 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.

Why This Pairing Usually Fails in Practice

Marlier's Julie and Wolf Fish 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.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Marlier's Julie and Wolf Fish.

Frequently Asked Questions

Can Marlier's Julie and Wolf Fish live together?

No. This combination is not recommended. Key incompatibilities — such as critical behavioural conflicts — make cohabitation unsafe.

What size tank do Marlier's Julie and Wolf Fish need?

A minimum of 450 litres (tank length at least 150 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 Marlier's Julie and Wolf Fish together?

Keep the aquarium between 23°C and 27°C. A target of around 25.0°C sits comfortably within both species' preferred ranges.

Are Marlier's Julie or Wolf Fish aggressive?

Marlier's Julie is moderately assertive (6/10) and Wolf Fish 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 Marlier's Julie and Wolf Fish need?

Their pH requirements do not overlap. Marlier's Julie prefers 8.2–9.3, while Wolf Fish needs 6–8. This makes them incompatible in the same water chemistry.

How do I manage Marlier's Julie's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Marlier's Julie space to claim a territory without encroaching on the other fish's area. Adding décor that divides the tank into distinct zones works especially well.

Does Wolf Fish being nocturnal affect compatibility?

Wolf Fish is most active after lights-out, which naturally reduces daytime encounters with its tank mate. This can actually be beneficial, as both fish get undisturbed time to feed and explore. Just ensure food reaches Wolf Fish during evening hours.

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
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