TankBud

Elephant-nose knifefish

Sternarchorhynchus oxyrhynchus

Also known as Tube-snout knifefish

FreshwaterFish

Elephant-nose knifefish (Sternarchorhynchus oxyrhynchus)

Care at a glance

Temperature
73–82°F
23–28°C
pH
5.5–7.2
Adult size
18.5 in
47 cm
Minimum tank
106 gal
400 L
Temperament
Mostly peaceful
Social behavior
Solitary
Tankmates
With caution
Swim level
Bottom
Diet
Carnivore
Difficulty
Difficult
Breeding
No record
Rarity
Rare
Family
Apteronotidae
Origin
Amazon and Orinoco river channels

Overview

The elephant-nose knifefish is a large, specialized electric knifefish for experienced keepers. It works the bottom of a dim, soft-water tank by night.

Did you know

The elephant-nose knifefish hunts with tweezers and radar at once. Its curved tube snout reaches into burrows and crevices for insect larvae. A weak electric field, which the fish generates and senses, helps it find prey it cannot see in the dark.

Caring for the elephant-nose knifefish

Keep an elephant-nose knifefish singly, in at least 106 gal (400 L). Give it a soft sand bed it can work over, tubes and wood for daytime shelter, and dim, shaded light. It stays near the bottom and probes the sand and crevices for hidden prey at night.

It wants warm, soft water at 73 to 82°F (23 to 28°C) and a pH of 5.5 to 7.2, with gentle to moderate flow. Feed meaty foods after dark, such as frozen bloodworm, blackworm and chopped prawn. Small sinking items suit it best, since it pulls its food out of the substrate.

The elephant-nose knifefish is mostly peaceful toward fish it cannot eat, but it hunts at night. Choose tank mates with caution, and avoid small fish and shrimp that could become food. It is not known to breed in the aquarium.

Good to know

The elephant-nose knifefish, Sternarchorhynchus oxyrhynchus, belongs to the ghost knifefish family, Apteronotidae. Its most striking feature is the long, tube-like, downcurved snout. It is also called the tube-snout knifefish.

In the wild

The elephant-nose knifefish lives in the channels of the Amazon and Orinoco and their tributaries. It stays over sand and among submerged wood, in warm, flowing water.

Common questions

What size tank does an elephant-nose knifefish need?

An elephant-nose knifefish needs at least 106 gal (400 L). It spends most of its time in the bottom.

What temperature and pH does an elephant-nose knifefish need?

An elephant-nose knifefish is comfortable at 73–82°F (23–28°C) with a pH of 5.5–7.2.

What does an elephant-nose knifefish eat?

An elephant-nose knifefish eats meaty foods such as frozen bloodworm, blackworm and chopped prawn, fed after dark. Small sinking items suit it best, since it pulls its food from the substrate.

How big does an elephant-nose knifefish get?

An adult elephant-nose knifefish reaches about 18.5 in (47 cm).

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