All Species
semi-aggressiveBottom dweller

Knifefish Care Sheet

Various (Chitala, Xenomystus)

Nocturnal predatory fish with a unique, blade-shaped body. Knifefish use weak electrical fields to navigate and hunt in the dark. Fascinating but for experienced keepers.

Temperature

7582°F

pH Range

67

Min Tank Size

100 gallons

Lifespan

10–15 years

Adult Size

8–20 inches (20–50 cm) depending on species

Group Size

1 (territorial with their own kind; some exceptions)

Breeding

Very difficult in captivity. Rarely attempted in home aquariums.

Diet & Feeding

Carnivore — frozen bloodworms, brine shrimp, live foods, meaty pellets. Can be trained to accept pellets with patience.

Natural Habitat

Native to rivers in Southeast Asia and Africa. Nocturnal hunters found in murky, slow-moving water with plenty of cover.

Care Tips

Strictly nocturnal — provide caves and dim lighting

Will eat any fish small enough to fit in their mouth

Clown knives grow to 20+ inches — need 150+ gallon tanks

Use weak electrical fields for navigation — sensitive to stray current

Black ghost knifefish are the most popular and best for home aquariums

Tank-Mate Compatibility

Use Caution (24)

Caution

Guppy

Semi-aggressive species — monitor for aggression.

Caution

Betta

Semi-aggressive species — monitor for aggression.

Caution

Corydoras

Semi-aggressive species — monitor for aggression.

Caution

Angelfish

Semi-aggressive species — monitor for aggression.

Caution

Molly

Semi-aggressive species — monitor for aggression.

Caution

Platy

Semi-aggressive species — monitor for aggression.

Caution

Swordtail

Semi-aggressive species — monitor for aggression.

Caution

Cherry Barb

Semi-aggressive species — monitor for aggression.

Caution

Harlequin Rasbora

Semi-aggressive species — monitor for aggression.

Caution

Dwarf Gourami

Semi-aggressive species — monitor for aggression.

Caution

Bristlenose Pleco

Semi-aggressive species — monitor for aggression.

Caution

Otocinclus

Semi-aggressive species — monitor for aggression.

Caution

Amano Shrimp

Semi-aggressive species — monitor for aggression.

Caution

Nerite Snail

Semi-aggressive species — monitor for aggression.

Caution

Mystery Snail

Semi-aggressive species — monitor for aggression.

Caution

Tiger Barb

Semi-aggressive species — monitor for aggression.

Caution

Danio

Semi-aggressive species — monitor for aggression.

Caution

Rainbowfish

Semi-aggressive species — monitor for aggression.

Caution

Clown Loach

Semi-aggressive species — monitor for aggression.

Caution

African Cichlid

Semi-aggressive species — monitor for aggression.

Caution

American Cichlid

Semi-aggressive species — monitor for aggression.

Caution

Goldfish

Semi-aggressive species — monitor for aggression.

Caution

Puffer

Semi-aggressive species — monitor for aggression.

Caution

Catfish

Semi-aggressive species — monitor for aggression.