Peter’s Elephantnose Care, Setup, & Amazing Facts

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peter's elephantnose care

When you hear “elephant nose,” you probably have an iconic image of Peter’s elephantnose in your head. But there are over 200 different species spread across 20 genera. Calling Mormyrinae a “big family” is a big understatement.

What you also may not know is that elephant fish are also weakly electric and can discharge 1 volt (which is totally harmless to humans.) This weak electrical shock comes from an organ that can sense prey lurking up to 2cm under the substrate. And the last cool fact for you before we get to the good stuff?

They have a huge brain for their body size, though it’s their cerebellum that’s enlarged, unlike mammals, which have an enlarged cerebrum. Because their brain is so large (and takes up so much energy to “run”) they use about 60% of their oxygen intake to power their brain.

By contrast, humans use about 20% and, prior to this discovery, we thought we held the record.

fallon deep breath gif

The reasons why you’d want to own an elephant nose are pretty clear. What’s not so clear to most people is how to take care of them. And, unfortunately, these guys are rarely taken care of properly. So if you don’t want to be one of those people (spoiler: you don’t!), read on to find out how to actually take care of these amazing animals!

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Table of contents

elephantnose care

Neat Facts

Gnathonemus petersii Classification

IUCN Status: Least Concern – Last assessed 5/1/2009

Class: Actinopterygii are ray-finned fishes, which is a subcategory of boney fishes. These fish are characterized by the bony structures that support their webbed fins. This group makes up nearly half of all living vertebrates.

Order: Osteoglossiformes are a primitive order of “boney tongue” or “toothy tongue” fish.

Family: Mormyridae is the family that houses elephantfish or elephantnose fish.

Genus: Gnathonemus houses four species of elephantnose fish, all of them are from Africa.

Species: Gnathonemus petersii

What does Gnathonemus petersii mean?

Gnathonemus comes from the Latin words gnathos, which means jaw, and nema, which means thread. This is a nod to their bottom jaw where their electrical organ is located.

Petersii is pseudo-Latin for a Peter. Which Peter – either first or last name – we don’t quite know, but sources seem to indicate it may be Wilhelm Peters. He was a prominent German naturalist in the mid-1800s when this species was discovered.

peter gif office space

Find Other Fish

Looking for something specific? You can discover other fish with similar characteristics! They open in a new tab so you can keep reading too!

Distribution & Natural Habitat

Peter’s Elphantnose have a vast distribution through plenty of places in West and Central Africa. They’ve been recorded in Mali, Benin, Niger, Nigeria, Chad, Central African Republic, Cameroon, Republic of Congo, Democratic Republic of Congo, and Zambia.

Peter's elephantnose natural habitat

They inhabit slow-moving dark and muddy riverbeds with heavy vegetation. This is the key reason that their electrical organ is so important. With this organ, they’re able to find food, find mates, and avoid predation in water that’s nearly impossible to see in.

Aquarium Care

Difficulty: Intermediate
Size: 9″ (22 cm)
Lifespan: 6 – 8 years
Tank Size: 60+ gallons (240+ liters)
Diet: Carnivore
Temperature: 73 – 82 F (23 – 28 C)

pH6.0 – 7.5
Hardness: 5 – 15 dKH
Temperament: Peaceful with most species
Breeding: Not done with long-term captive individuals (see breeding section)
Swimming: Bottom
Availability: Common online, uncommonly kept

They’re predominantly nocturnal, so if you want to see them, you’re going to need dim lighting or red lighting. I cover some lighting ideas more thoroughly below. They can also get highly aggressive with their own species once they’re fully-grown, so make sure you have a backup plan (or three) in the event things go south.

Another important thing to note is that because their brain uses so much oxygen, they have exceptionally high oxygen demands for a fish that doesn’t like moving water. I address this issue further in the filtration section as well.

Tank Specs

60 gallons is the starting point, but 125 is better, and 250 is better still. Particularly because these guys do best with the company of their own kind, but they need room. And, preferably, at least six of them.

When we’re talking about that many 9″ long fish in one tank, it’s not so much the gallonage that matters here, but the footprint the tank has. If you’re handy, you can custom build a tank that’s relatively cheap.

If you’re not familiar with building massive tanks, this video is a good place to start.

They’re also sensitive to fluctuations, so you’re going to want to make sure you have a lid as well as a good heater (preferably hooked up to a controller) to keep things super stable for them. I have the best heaters and controllers below, but if you’d like more detailed information or more heaters to look at, you can check my detailed review of the best aquarium heaters.


Peter’s Elephantnose fish do best as the only mormyrid or in groups of six or more of their own kind (as in Peter’s Elephantnoses, not other mormyrids.) Again, to house a group that large, you’re basically going to need an elephant house.

But it’d be really cool.

With that said, they do well with other species of fish and I get into the ins-and-outs of tank mates in a whole separate section.


These guys come from areas with tons of plants, so you’re definitely going to want to add some of those. If you plan on having an elephant herd, you’re also going to want plenty of places where each elephantnose can hide and definitely some ways to break up and distribute their territory.

elephantnose tank

The other thing they really need is sand. Most of their natural behavior hinges on sand. They hunt for food in the sand, the push their proboscis (“nose”) in the sand pretty much constantly, and without sand – or with a sharper substrate – they’re going to damage themselves.

Housing them on something like rocks or pebbles is super cruel. Not only is there a good chance that they could damage their proboscis, but they can also get a bacterial or fungal infection if they’re not housed on sand or silt – though I don’t recommend that latter.

HTH pool filter sand is a great substrate, I even use it with my pygmy cories and their barbels are long and gorgeous! Unfortunately, the mix of sand and lots of plants isn’t great – especially when you add in lighting requirements. Fortunately for you, I cover what you can plant without fancy fertz or substrates below.

Best Plants For Peter’s Elephantnose Fish

You’re going to want to grab plants that blot out the overhead light without dense root structures, plants that can tolerate low light, and plants that can grow in sand or on driftwood or rocks. Fortunately, this still leaves a good deal of easy and affordable options for your elephants!

This definitely isn’t a complete list, but I hope it’ll help get some thoughts going.



Salvinia is a fast-growing plant good for keeping ammonia, nitrates, and nitrites under control. It’s great for providing shelter for scared fish and fry, keeping the lighting intensity down. and making skittish fish feel more secure.

Difficulty: Easy
Growth: Fast
Temperature:  64 – 86F (18 – 30C)

pH: 5.0 – 8.0
Hardness:  2 – 25 dKH
Placement: Floating

Java Moss

Java moss

Java moss is an almost bulletproof plant that requires almost no care. It doesn’t grow nearly as slowly as it’s java fern cousin, and can create lush moss beds that blow and billow in the current. They’re a great option for grazers, fry, or those of you with the blackest of thumbs.

Difficulty: Easy
Growth: Moderate
Temperature: 59 – 86F (15 – 30C)

pH: 5.0 – 8.0
Hardness: 3 – 12 dKH
Placement: Floating or attached

Water Wisteria

Water wisteria is a fast-growing plant good for keeping ammonia, nitrates, and nitrites under control. It’s great for providing shelter for scared fish and fry, keeping cyanobacteria (aka blue-green algae) at bay, and has anti-microbial properties.

Difficulty: Bulletproof
Growth: Slow
Temperature:  64 – 86F (18 – 30C)

pH: 5.0 – 8.0
Hardness:  2 – 25 dKH
Placement: Anywhere, basically



Duckweed can be a blessing or a curse. It’s a small floating plant that’s impossible to kill and can quickly and cheaply cover the top of your tank. The tough part is that it’s nearly impossible to fully get rid of once it’s in your tank.

Difficulty: Easy
Growth: Moderate
Temperature: 59 – 86F (15 – 30C)

pH: 3.0 – 8.0
Hardness: 0 – 25 dKH
Placement: Floating

Anubias (Anubias barteri)

anubias barteri

The anubias barteri species has over 13 variants that call it home – so if you think you’ve seen them all, your probably wrong. They range in size, color, and shape, and are nearly guaranteed to be bulletproof. They don’t experience melt as often as most other immerse-grown aquarium plants and do well in low-tech setups – even with plant-munching fish. 

Difficulty: Easy
Growth: Slow
Temperature: 72 – 82F (22 – 28C)

pH: 6.0 – 8.0
Hardness: 2 – 25 dKH
Placement: Floating or attached

Java Fern

Java Fern

Java fern is a nearly indestructible low light plant that can put up with tons of abuse. It doesn’t need Co2, fertilizers, or fancy soils. There are tons of lush, beautiful, jungle-like aquascapes you can create with it too!

Difficulty: Bulletproof
Growth: Slow
Temperature:  64 – 86F (18 – 30C)

pH: 5.0 – 8.0
Hardness:  2 – 25 dKH
Placement: Anywhere, basically



Vals come in a ton of varieties, but most of them are about the same to grow. They can grow rapidly, and quickly cover your tank with lush, kelp-like forests for your fish. Some species, however, do grow much shorter than others.

Difficulty: Easy
Growth: Moderate
Temperature: 63 – 82 F (17 – 28 C)

pH: 6.5 – 8.5
Hardness: 3 – 30 dKH
Placement: Planted

Lighting & Filtration

Peter’s elephantnoses are primarily nocturnal and don’t do well with lighting. This gives you a few options. You can use a ton of plants and hope that you see them occasionally. You can get an adjustable light and keep the lighting to a minimum with ultra low-light plants. Or – probably my favorite – you can get an adjustable light and put the red only light on during the day, and the bright light for the plants on at night.

This way, you can see them during the day since these guys can’t see red light, but you can still keep your plants. And, as far as every study I’ve read goes, there are no negative effects on flipping their schedule. If this sounds like the solution you also prefer, the Fluval 3.0 Planted light is the only one that I’m aware of that you could do this with.

Filtration is another big factor we have to tackle though. They’re big fish that don’t handle deteriorating water quality, but they also don’t deal well with water movement, but they need a ton of oxygen. This leaves you with the options of an adjustable but efficient canister filter or a sump, but either would likely need a spray bar to keep the flow rate reasonable, but also keep the water clean and highly oxygenated.

You’ll also likely want an air pump with an airstone just to be sure they’re getting enough oxygen.

Water Care

Peter’s elephantnose fish are sensitive to deteriorating water quality, so you’ll want to do 25% weekly water changes on your tank if you have a small tank. If you have a large tank, you can probably get away with 15% or 10% weekly depending on your setup. As always, you’ll want to make sure your ammonia is 0 ppm, your nitrites at under 5 ppm, and your nitrates are 5 ppm or under.

Since their tanks are usually pretty large, you’re probably going to want to invest in something like a Python to help make water changes faster, easier, and you’ll probably be more willing to do them more often with one.

Like all scaleless fish, elephantnose fish are sensitive to meds and salt. These guys are also temperature sensitive, so you’re going to want to rely almost entirely on prevention. This means good food, good water – and lots of both. In the event your elephantnose gets sick, you may have to run half doses – if you can meds dose at all.

Fortunately, with the right care they shouldn’t get sick, but if they do, the meds you’ll likely need are listed below (and are all scaleless fish safe!)

Feeding Elephant Fish

Peter’s elephantnose love mosquito larvae and will pick it over any other foods. However, they’re fond of any wiggly-worm-like critter. Bloodworms, whiteworms, and small earthworms are all good options for live food as well. If you can’t get live versions, you can use frozen bloodworms and hide them under the sand for them to “hunt” as well.

They’ll take most frozen, freeze-dried, or pellet foods as long as they reach the bottom of the tank and it fits in their mouth. They don’t really chew, they kind just vacuum food in, so keep that in mind.

If you’re stuck on what to get, I included some additional suggestions below for you as well.

Common Elephant Fish Diseases

Aside from damaging their electrical organ (or whole mouth) on unsuitable substrate, elephantnose fish are pretty healthy. However, there are a few things that seem to pop up more often than others. Again, I listed all the meds they should need to stay tip-top in the water care section if you want to come prepared.

Be aware that all Peter’s elephantnose fish are wild-caught, which means they could carry anything that lives in the wild with them. Be vigilant while they’re in QT and on the lookout for things like…

Bacterial Infection

bacterial infection

Bacterial infection is a broad term, the bacteria family can cause a wide range of symptoms and come from varying causes. Generally, you can treat them with a broad spectrum antibacterial regardless of the particular bacteria at hand. It’s diagnosing that’s usually the hard part.

Making matters even more difficult, fish can have an internal or external bacterial infection.


  • Red streaks
  • Red ulcers
  • Fuzzy growths
  • Pop eye
  • Bloating


  •  Poor water quality
  • Food that’s gone bad
  • Keeping fish in inappropriate water parameters
  • Stress

Fungal Infection

fungal infection

Fungal infections are a tricky bunch – not only do they have a huge family that presents a wide variety of species and symptoms – but some bacterial infections look strikingly similar to a fungus. 

If you’re not sure if you’re dealing with a fungus or a bacterial infection, I find it helpful to treat with Ich X and Erythromycin (provided it’s 100% erythromycin) at the same time to be sure I’m treating for both.


  • Cottony growths on body, fins, eyes, and/or gills


  • Prior untreated injury
  • Stress
  • Water quality-related issues
  • Prior untreated infection (bacterial, parasitic, etc.)

Columnaris (Cotton Mouth Disease)

columnaris disease

Occasionally called false neon tetra disease or cottonmouth, this is caused by a gram-negative bacterium. it can also, quite understandable, be confused with fungal infections. 


  • Discolored scales
  • Scales appear to be popping off (not “pineconing”)
  • Grey spots
  • Lesions on the back
  • Legions around the mouth
  • May result in fuzzy patches due to secondary infections


  •  Flavbacterium columnare (bacteria)

Skin & Gill Flukes

skin and gill fluke

Skin and gill flukes are worm-like parasites that embed into your fish. Since they’re so small, they’re almost invisible to the naked eye and incredibly difficult to diagnose. 

Before you freak out, flukes are present in almost every tank and are harmless under normal conditions.


  • Excess mucus on skin
  • Redness in gills and on skin
  • Itchiness
  • Scratching
  • Labored breathing (if in gills)


  • Generally, stress
  • Previous illness
  • Overcrowding
  • Wrong water parameters



Tapeworms are small rice-like worms that can drop out of your fish’s anus with or without passing poop with it. Due to the small size of the segments these worms break into, it can be incredibly hard to diagnose in fish.


  • Sunken stomach
  • Inability to grow
  • Generally not thriving


  • Infected by another fish

13 Elephantnose Tank Mates

Elephantnose fish are best with others of their own kind. In the wild, they’re found in large shoals containing dozens of elephantnose fish! Of course, for this to be successful, you need to keep at least five of them in a rather large tank (125 gallons) to spread out the aggression – eight or more being the best option (around a 250-gallon.)

Of course, with all that space, you can still throw in some large schools of smaller species. Or for a single specimen tank (again, totally don’t recommend!) you could add some larger species. Just be sure that they’re not going to be aggressive when spawning or territorial over the substrate (so, no, I don’t recommend cichlids at all.)

It’s also important to avoid fish that can easily outcompete the slow-moving elephantnose and remember that each elephantnose is different. Some might tolerate some species on this list while others won’t have it. Usually when they’re kept as the only elephantnose, once they become adults they’re pretty antisocial, but if they grow up with the proper amount of fellow elephantnoses, this seems to be less of an issue.

Emperor Tetra (Nematobrycon palmeri)

emperor tetra

Emperor tetras are one of the best community tetras you can find. They’re hardy, easily adaptable, peaceful, and large enough to not be easily startled. They’re best kept in shoals of 6 or more, with 10 or more being better.

pH: 5.0 – 7.5
dKH: 1 – 12
Temp: 74 – 81 F (23 – 27 C)

Size: 2″ (5 cm)
Temperament: Peaceful and active
Swimming: Top to midwater shoaling

Black Neon Tetra (Hyphessobrycon herbertaxelrodi)

black neon tetra

Not to be confused with the black tetra (or “black skirt” tetras) or neon tetras (Paracheirodon innesi,) the black neon tetra is a separate species. They do best in groups of eight or more – but more is always better when it comes to shoaling fish. They have the peaceful demeanor of the neon tetra without all the health issues. 

pH: 5.5 – 7.5
dKH: 4 – 9
Temp: 73 – 81F (23 – 27C)

Size: 1.5″ (3 cm)
Temperament: Peaceful shoaling fish
Swimming: Mid to top

Bristlenose Plecos (Ancistrus sp.)

bristlenose pleco

Most plecos aren’t suited for the average aquarium, some growing up to two feet long – not the bristlenose pleco. They’ll happily munch on algae, green beans, zucchinis, cucumbers, sinking algae wafers, and of course leftovers and fish poo – although leftovers and poo make for a literally shitty diet.

pH: 6.0 – 7.5
dKH: 6 – 10
Temp: 60 – 80 F (15 – 27 C)

Size: 4 – 5″ (10 – 12 cm)
Temperament: Peaceful, can be territorial
Swimming: Everywhere that has structure

Bichirs (Polypterus sp.)

senegal bichir

Bichirs, affectionately called “pollys,” are thought to be living fossils and some reports indicate they might be a missing link between water-dwelling species and species who eventually migrated onto land – though there’s little evidence to support it. 

pH: 6.2 – 7.8 – species dependent
dKH: 5 – 20 – species dependent
Temp: 75 – 82 F (24 – 28 C) – species dependent

Size: 12 – 39″ (30 – 97 cm)
Temperament: Somewhat aggressive towards other fish, aggressive towards own kind
Swimming: Bottom

Kuhli Loach (Pangio kuhlii)

Kuhli loach

Kuhli loaches are easy to keep, but they need food that hits the bottom of the tank. If you have the chance, hiding food under the sand is a great way to see their natural behavior and it’s fun to watch them root around for scraps. They like to be kept in groups where you’ll often see them curled up under structures together.

pH: 3.0 – 7.0
dKH: 1 – 8
Temp: 70 – 79 F (21 – 26 C)

Size: 1.3″ (3 cm)
Temperament: Peaceful, can be shy
Swimming: Bottom

Diamond Tetra (Moenkhausia pittieri)

Diamond tetras make a great addition to most community tanks, but they can be nippy. They’re typically peaceful, active, unfussy, and generally mind their own business. They do best in shoals fo 6 – 8. If there’s more than that, they tend to nip tankmates instead of each other.

pH: 5.5 – 7.0
dKH: 5 – 12
Temp: 75 – 82 F (24 – 28 C)

Size: 2.4″ (6 cm)
Temperament: Peaceful shoalers
Swimming: Mid to top

Congo Tetra (Phenacogrammus interruptus)

congo tetra

Wild populations are endemic to the Congo River in Africa, but thankfully, we have plenty of captive-bred fish on the market. They do best in groups of at least six.

pH: 6.0 – 7.5
dKH: 3 – 18
Temp: 73 – 82 F (23 – 28 C)

Size: 3.2″ (8 cm) max
Temperament: Peaceful shoaler
Swimming: Mid to top

Marbled Hatchetfish (Carnegiella strigata)

marbled hatchetfish

A tight-fitting lid is a must for these guys because they jump high and often. They tend to do best with floating vegetation, which helps reduce their jumpiness and should be housed in groups of 6 or more – emphasis on the more.

pH: 4.0 – 7.0
dKH: 1 – 10
Temp: 68 – 83 F (20 – 28 C)

Size: 1.3″ (3 cm)
Temperament: Peaceful, but easily jump
Swimming: Surface to top

African Butterfly Fish (Pantodon buchholzi)

African butterfly fish

African butterfly fish make an interesting and unusual addition to any tank with a secure lid. They’re fantastic jumpers, but otherwise, they typically don’t move a ton. They tend to hang out at the surface under vegetation and ambush prey. Additionally, they’re typically crepuscular.

pH: 6.0 – 7.5
dKH: 5 – 15
Temp: 73 – 86 F (23 – 30 C)

Size: 4.8″ (12 cm)
Temperament: Peaceful, but will eat small tankmates
Swimming: Surface

African Leaf Fish (Polycentropsis abbreviata)

African leaf fish tend to do best on their own, but with the right tankmates they can do well. They often move very little and usually just drift around like a leaf. They need softer, warmer waters, lots of plants, and frozen or live foods in order to thrive.

pH: 6.0 – 6.5
dKH: 1 – 10
Temp: 79 – 88 F (26 – 31 C)

Size: 3.2″ (8 cm)
Temperament: Peaceful, but will eat small tankmates
Swimming: Everywhere

Orange Bushfish (Microctenopoma ansorgii)

If you’ve never heard of these guys before, you’re officially forgiven. They’re a small bushfish from, primarily, the Congo. They can get aggressive with one another when spawning or if they don’t have enough room, but spawning events are rare.

pH: 5.5 – 7.5
dKH: 5 – 20
Temp: 68 – 80 F (20 – 27 C)

Size: 2.4″ (7 cm)
Temperament: Peaceful, can be aggressive with own kind
Swimming: Generally mid-water

Glass Catfish (Kryptopterus vitreolus)

glass catfish

Glass cats (also called ghost catfish) do best in heavily planted tanks with subdued lighting and a small herd of their own kind to shoal with, I suggest a minimum of at least 6 – though 8 or more is certainly better.

pH: 4.0 – 7.0
dKH: 1 – 10
Temp: 68 – 79 F (20 – 26 C)

Size: 2.1″ (6 cm)
Temperament: Peaceful shoaling fish
Swimming: Bottom to middle

Ropefish (Erpetoichthys calabaricus)

Reedfish, ropefish, snakefish – whatever you want to call them, they’re thin bichir-like fish that have the most adorable smiling faces. Despite their looks, they’re competent escape artists and need a tight-fitting lid and some structure to tuck into to hide.

pH: 6.0 – 7.5
dKH: 5 – 20
Temp: 73 – 86 F (23 – 30 C)

Size: 36″ (90 cm)
Temperament: Peaceful, but will eat any fish it can
Swimming: Bottom/in caves and structures

Breeding Peter’s Elephantnose Fish

Several species of wild-caught elephantnose fish have bred successfully in captivity under strict conditions. Brienomyrus brachyistius is the one scientists have had the most success with so far. Water conductivity using deionized water seems to be large part of the success of the few breeding reports we do have.

Peter’s elephantnose aren’t much different, they spawn somewhat reliably after they’re caught and quickly lose interest – or the ability.

In one study, after only two weeks of captivity, the electrical organ discharge frequency of both males and females become identical. Courtship activity was still happening at this time, but it wasn’t effective because they couldn’t differentiate each other. After a month, the fish’s hormone levels also changed. Some females showed higher testosterone levels than the males.

Captive breeding of mormyrids that have been captive long-term remains elusive, but scientists are making progress. With that said, there is no information on the hatch rates or care for the fry yet. Honestly, I’m not sure we’ve unlocked that one just yet.

Other Elephantnose & Mormyrid Species

Like I said, the mormyrid family is huge, boasting over 200 species from over 20 genera. So, while we’re here… why not take a look at some lesser-known and lesser appreciated elephantnose fish?

baby whale fish

Baby Whale

This is the species that scientists have had to most success breeding in captivity, so if you want to know more, this study is a great place to start.

Cornish Jack

Yes, this guy is – in fact – a mormyrid. Despite looking for all the world, much like an oversized catfish. And, if you hadn’t guessed it’s the biggest species. They can weigh in at as much as 33 lb (or 15 KG.)

Petrocephalus catostomus

This is the smallest mormyrid species, coming in at 3″ (4.5 cm) fully grown. And while you’re definitely going to want such and adorable mini sleeper shark critter, it’s currently not possible as far as I’m aware.

Campylomormyrus numenius

AKA the bird-beak elephantnose fish. And, while I feel like that doesn’t need an explanation, the coolest part about these guys is that their mouth is actually on the bottom – not above – their trunk.

This is one of the few times I’m going to cut it short because I truly hope you want to learn more about these guys. They’re an amazing family of fish with such a wide range of diverse species. If you’re interested in learning more, there are some additional studies linked below as well!

Further Reading & Resources

New ScientistZoologger: Fish with elephant’s nose and crystal eyes

Sci News – Elephantnose Fish Use Electric Colors to Reliably Identify Prey, Study Says – Elephantnose fish’s unique retina helps it see through mud

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