Can Peter's Elephantnose Fish and Severum Live Together?

Reviewed by Guidarium Editorial DeskUpdated April 28, 2026
Possible with Caution

Keeping Peter's Elephantnose Fish and Severum together is possible but requires caution, though some care is needed. Provide a spacious tank of at least 280 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Peter's Elephantnose Fish

Gnathonemus petersii

Severum

Heros severus

🐠Family Group
Peter's Elephantnose Fish
Oddballs
Severum
Cichlids - South American
Temperament
Peter's Elephantnose Fish
Mostly Peaceful (4/10)
Severum
Semi-Aggressive (5/10)
Temperature
✓ Compatible
Peter's Elephantnose Fish
23–28°C
Severum
24–29°C
pH Range
✓ Compatible
Peter's Elephantnose Fish
6–7.5
Severum
6–7.5
Hardness (dGH)
✓ Compatible
Peter's Elephantnose Fish
2–15
Severum
4–15
Water Type
✓ Compatible
Peter's Elephantnose Fish
Freshwater Only
Severum
Freshwater Only
Flow Preference
✓ Compatible
Peter's Elephantnose Fish
Moderate
Severum
Moderate
Min Tank Volume
Combined: 280 L
Peter's Elephantnose Fish
200 L
Severum
280 L
Swimming Level
Shared: 2 zones
Peter's Elephantnose Fish
BottomMiddle
Severum
MiddleBottom
🏷️Behavior Tags
Peter's Elephantnose Fish
NocturnalShy / Slow Moving (Easily Stressed)Jumper (Lid Required)Aggressive to same species/look-alikes
Severum
Plant DestroyerTerritorial (Defends specific area)Digger (Disturbs Substrate)
Stocking calculator

Can your tank handle Peter's Elephantnose Fish and Severum?

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.

Peter's Elephantnose Fish
Severum
Test both in my tank

Behaviour & Temperament

Peter's Elephantnose Fish is a generally mild-mannered species (4/10), while Severum is moderately assertive (5/10). This modest difference means Severum may occasionally assert dominance over Peter's Elephantnose Fish.

Peter's Elephantnose Fish and Severum 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.

Worth noting: Peter's Elephantnose Fish is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Peter's Elephantnose Fish is a known jumper, so a tight-fitting lid is essential.

To improve the chances of a peaceful coexistence in this community tank: Provide a significantly larger tank (at least 50% more volume than the minimum) to allow both Peter's Elephantnose Fish and Severum to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations.

Water Parameters

The safe temperature window for both species falls between 24°C and 28°C. Aim for the midpoint of this range (around 26.0°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 4–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Peter's Elephantnose Fish and Severum together, plan for an aquarium of at least 280 litres with a minimum length of 120 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: Sand (Sifters), Smooth Gravel (Sensitive Barbels), Plants - lighly covered, Driftwood (Digestion/Hiding). Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Severum is a plant destroyer, which conflicts with Peter's Elephantnose Fish's requirement for live plants. Compromise where possible or prioritise the more critical need.

Both species do well with moderate (standard) water movement, so a standard filtration setup rated for the tank volume should suffice.

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. Peter's Elephantnose Fish and Severum 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.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Peter's Elephantnose Fish and Severum.

Show 1 more tank size

Frequently Asked Questions

Can Peter's Elephantnose Fish and Severum live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 280 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Peter's Elephantnose Fish and Severum need?

A minimum of 280 litres (tank length at least 120 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 Peter's Elephantnose Fish and Severum together?

Keep the aquarium between 24°C and 28°C. A target of around 26.0°C sits comfortably within both species' preferred ranges.

Are Peter's Elephantnose Fish or Severum aggressive?

Peter's Elephantnose Fish is generally mild-mannered (4/10) and Severum is moderately assertive (5/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Peter's Elephantnose Fish and Severum 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.

How do I manage Severum's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Severum 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 Peter's Elephantnose Fish being nocturnal affect compatibility?

Peter's Elephantnose 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 Peter's Elephantnose Fish during evening hours.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
April 28, 2026
Last updated
April 28, 2026
Issues or corrections?
Contact the editorial team

Related Comparisons