Peter's Elephantnose Fish

Gnathonemus petersii

Oddballs

A highly intelligent, nocturnal oddball native to African rivers. They navigate, communicate, and hunt using a weak electrical field generated from a specialized organ in their tail and a highly sensitive 'trunk' (a specialized chin appendage). A soft sand substrate is absolutely mandatory to prevent their trunk from being damaged by abrasion. They are notoriously aggressive toward conspecifics unless kept in very large shoals in massive aquariums.

At a Glance

Adult Size25 cm
Body ShapeCompressed
Growth RateModerate
TemperamentMostly Peaceful
Water TypeFreshwater Only
Flow PreferenceModerate
Waste OutputMedium
StockingSolo or group

Tank Requirements

Minimum Volume200 L
Minimum Length120 cm
FlowModerate
Water TypeFreshwater Only
Must-Haves in the Tank
Sand (Sifters)Smooth Gravel (Sensitive Barbels)Plants - lighly coveredDriftwood (Digestion/Hiding)

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Water Parameters

Temperature2328°C
pH67.5
Hardness215 dGH

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Temperament & Compatibility

Aggression LevelMostly Peaceful
4/10
Where They Swim
Surface
Mid-level
Bottom
Stocking Guidelines
Keep at Least1 (solo is fine)
Max per TankNo limit
Can Live Alone?Yes
Behavior Traits
NocturnalShy / Slow Moving (Easily Stressed)Jumper (Lid Required)Aggressive to same species/look-alikes

Available Varieties

Each variety inherits the species defaults above. Only differences are highlighted.

Standard / Adult

The fully grown adult form. Requires a minimum 4-foot (120cm) tank to establish its electrical territory. Extremely sensitive to water quality and medications.

Differs in 1 trait from base species

Also known as: Adult Elephantnose

Behavior Traits
NocturnalShy / Slow Moving (Easily Stressed)Jumper (Lid Required)Aggressive to same species/look-alikes

Juvenile (Grow-out)

Typical sale size in local fish stores. While they can temporarily be housed in smaller aquariums, they require a fast upgrade to a permanent 4-foot tank. Soft sand is still mandatory.

Differs in 4 traits from base species

Also known as: Baby Elephant Nose

Adult Size10 cm
Min Volume110 L
Min Length90 cm
Growth RateFast

Peter's Elephantnose Fish Care Guide Summary

The Peter's Elephantnose Fish, scientifically known as Gnathonemus petersii, belongs to the Oddballs family group. Adults reach a maximum size of approximately 25 cm and have a compressed body shape with a moderate growth rate. Classified as mostly peaceful, this species primarily occupies the bottom and mid-level zones of the aquarium and produces a medium level of biological waste.

To thrive, the Peter's Elephantnose Fish requires a freshwater only aquarium with a minimum volume of 200 litres and a tank length of at least 120 cm. Water temperature should be maintained between 23°C and 28°C, with a pH range of 67.5 and a general hardness of 215 dGH. A moderate water flow is preferred. An aquarium test kit can help you monitor these values.

Due to its specialist needs, the Peter's Elephantnose Fish is best suited for fishkeepers who can provide a carefully planned setup. This species is available in 2 varieties: Standard / Adult and Juvenile (Grow-out). Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.

Peter's Elephantnose Fish Habitat Setup

When setting up an aquarium for the Peter's Elephantnose Fish, a moderate water flow best suits their natural preferences. Because this species occupies the bottom and mid-level zones, the aquarium layout should prioritise open swimming space in the centre of the tank for free movement and sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include a sand substrate to accommodate their sifting behaviour, smooth gravel or rounded substrate to protect their sensitive barbels, driftwood, which can serve as both a hiding place and a dietary supplement, and light plant coverage for partial shade. Keepers should note that a tight-fitting lid is essential, as this species is a known jumper. Browse aquarium sand substrate options to find the best fit.

Peter's Elephantnose Fish Compatibility Notes

Classified as mostly peaceful, the Peter's Elephantnose Fish is adaptable and can be kept singly or in a small group, offering flexibility when planning a community tank. When choosing tankmates, conspecific aggression can be intense, especially in smaller tanks and boisterous or fast-moving tankmates may cause this species undue stress. Selecting tankmates that favour different water layers from the bottom and mid-level zones can help reduce competition and territorial overlap.

Recommended Tank Sizes

Standard aquarium sizes that meet the minimum volume and length requirements for Peter's Elephantnose Fish.

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Frequently Asked Questions About Peter's Elephantnose Fish

How big does Peter's Elephantnose Fish get?

Peter's Elephantnose Fish (Gnathonemus petersii) typically reaches a maximum adult size of approximately 25 cm. They have a compressed body shape and a moderate growth rate.

What tank size does Peter's Elephantnose Fish need?

A minimum aquarium volume of 200 litres and a tank length of at least 120 cm are recommended for Peter's Elephantnose Fish. This ensures enough swimming space and helps maintain stable water conditions.

What water parameters does Peter's Elephantnose Fish need?

Peter's Elephantnose Fish thrives in freshwater only conditions with a temperature range of 23–28°C, a pH between 6 and 7.5, and a general hardness of 2–15 dGH. A moderate water flow is preferred.

Is Peter's Elephantnose Fish peaceful or aggressive?

Peter's Elephantnose Fish is classified as mostly peaceful with an aggression score of 4 out of 10. They are generally well-suited to peaceful community tanks.

Can Peter's Elephantnose Fish live alone?

Yes, Peter's Elephantnose Fish can be kept singly or in a group. They are flexible and adapt well to both setups.

Does Peter's Elephantnose Fish have any special tank requirements?

Yes. Peter's Elephantnose Fish benefits from sand (sifters), smooth gravel (sensitive barbels), plants - lighly covered, and driftwood (digestion/hiding) in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.

Does Peter's Elephantnose Fish need a lid on the tank?

Yes. Peter's Elephantnose Fish is a known jumper, and a tight-fitting lid or cover is essential to prevent escape. Even a small gap can be enough for a determined fish to leap out.


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