Seriously Fish
AdminAccount
AdminAccount

Gymnotus pedanopterus

Zebra Knifefish

Authority not recorded

Last revised 2026Edit this page

On this page11 sections
Gymnotus pedanopterus
Gymnotus pedanopterusJJPhoto

Quick factsEdit

Max size
280mm SL11in SL
Aquarium size
not recorded
Temp
22–28°C72–82°F
pH
6.0–7.0
Hardness
2–12dGH

Difficulty4 of 8 measures

Moderate

How the rating is worked out

Space
very large tank
Water
needs a steady pH
Temp
flexible
Diet
unknown
Temperament
eats smaller fish
Social
unknown
Compatibility
unknown

Other demands

Each of these can raise the rating on its own, whatever the measures above say.

Hardiness
unknown
  • Needs a very large tank

The zebra knifefish, Gymnotus pedanopterus, is a gymnotid knifefish from Peru and Brazil, one of over 20 Gymnotus species described since 1994. It grows to at least 28 cm and inhabits sluggish or still, turbid waters. Like other gymnotids it produces a weak electric field that it uses to navigate and communicate, and it is sensitive to many aquarium medications, particularly those containing copper.

Distribution

Edit

Tends to inhabit sluggish or still waters, and seems to prefer turbid environments. It is also found in the deeper parts of main river channels, and in general is considered a benthic (bottom dwelling) species.

Aquarium size

Write a noteEdit
Standard length
280mm SL11in SL
Aquarium base
not recorded

48" x 12" x 12" (120cm x 30cm x 30cm) - 108 litres if kept alone as a single specimen. Larger if kept in a community situation.

Maintenance

Write a noteEdit

Decor isn't critical, although it does appreciate plenty of cover. Large stones and pieces of bogwood, twisted roots, and live plants all look good. It is also much more active under dim conditions, so either use weak lighting or add a layer of floating plants to diffuse the light entering the tank.

Water conditions

Edit
Temperature
22–28°C72–82°F
pH
6.0–7.0
Hardness
2–12dGH

Temperature: 22 – 28 °C72 – 82 °F

pH: 6.0-7.0

Hardness: 2-12°H

Offer it live and frozen foods such as bloodworm, prawns, earthworms, tubifex etc. Dried foods are not usually accepted.

These recommendations come from this profile’s own figures. They contain affiliate links, so we may earn a commission.

Behaviour and compatibility

Write a noteEdit

Small fish will be eaten, but it can be combined with other similarly-sized species in a big enough tank. Don't keep it with anything too boisterous or aggressive though, or it might become withdrawn. Possible tankmates include large, robust cichlids such as Cichla or Geophagus sp., larger Characins, Cyprinids, catfish, Loricariids and other species such as bichirs. It's very territorial with conspecifics, and a very big tank would be needed to keep more than a single specimen.

Sexual dimorphism

Write a noteEdit

Unknown.

Reproduction

Write a noteEdit

Unknown.

Notes

Edit

The genus Gymnotus has undergone considerable taxonomic revision in recent years, with over 20 new species being described since 1994, of which this stunning species is one. It's still very rare in the hobby and tends to command a high price when available. Like other Gymnotids, it produces a weak electric field using specially-adapted muscle tissue located towards the tail. It also possesses electroreceptors which allow the fish to receive electrical signals. With these the fish can sense the tiniest of movements as the field around it is disturbed, and navigate in total darkness, useful skills when hunting prey or avoiding predators in the dark. What is most fascinating about this adaptation is that the fish also use it to communicate with each other and find partners.

A final point to note is that it's sensitive to many aquarium medications, particularly those containing copper.

Distribution

Profile completeness18 of 24

Community

Questions about Gymnotus pedanopterus?

Ask on Discord