Felix's elephantfish

Where they come from

Felix's elephantfish (Mormyrus felixi) is one of those West and Central African mormyrids that makes you realize fish can be downright weird in the best way. They come from slow to moderate waters where visibility can be lousy, so they lean hard on their electric sense to navigate and hunt. That's why they act a little "blind" in bright, bare tanks, but suddenly look confident once you set them up the way they like.

Setting up their tank

If you try to keep this species like a typical community fish, you'll be frustrated and the fish will be stressed. Give them space, dim light, lots of cover, and a bottom they can actually work over.

• Tank size: I'd treat 75 gallons as a starting point for one adult, and bigger is better. If you're aiming for more than one, think 125+ with lots of broken sight lines.
• Substrate: fine sand. They spend a lot of time nosing around, and rough gravel will beat up the mouth and chin area.
• Hardscape: driftwood and smooth rocks arranged to make lanes, caves, and "rooms". They like being able to move without crossing open ground.
• Plants: tough stuff that can handle low light (Anubias, Java fern) or floaters to dim things down.
• Flow and filtration: clean, well-oxygenated water with decent filtration. Moderate flow is fine, but I avoid blasting the whole bottom with a powerhead.
• Lighting: low to moderate. Bright lights make them skittish and more likely to hide or refuse food.

They hate sudden changes. Keep the temperature stable, keep up with water changes, and don't let nitrates creep up. If you can, run the tank like a quiet, mature setup rather than a constantly tinkered-with project.

What to feed them

Mine behaved like picky nocturnal predators. They usually ignore flakes and most pellets at first. Once they recognize food, they can be steady eaters, but you have to meet them halfway.

• Best staples: earthworms (chopped), blackworms, live or frozen bloodworms, frozen mysis, chopped shrimp or clam.
• Good extras: insect larvae, small chunks of fish or prawn (not every day), quality sinking carnivore pellets once they're taking prepared foods.
• Feeding schedule: small amounts after lights down, 4-6 nights per week. Young fish do better with more frequent smaller feeds.

How they behave and who they get along with

They are intelligent, cautious, and surprisingly interactive once they settle. During the day you might only see a nose sticking out of wood. At night, they're out cruising and probing the sand like a little submarine.

Compatibility is where people get burned. They can be territorial with their own kind, and they will eat anything small enough to fit in their mouth. They also get stressed by hyperactive fish that never stop moving.

• Good tankmates: calm medium-to-large fish that won't nip or outcompete them at feeding time (bigger Congo tetras, larger peaceful cichlids that aren't aggressive, Synodontis catfish with similar size).
• Avoid: fin nippers, super fast surface feeders that steal everything, aggressive cichlids, and small fish or shrimp you don't want eaten.
• Keeping multiples: possible in a big tank with lots of hides, but expect sparring. If you try it, add them together and provide several separate shelters.

Breeding tips

Breeding Felix's elephantfish in home aquariums is uncommon. Most of what you see in the hobby is wild-caught, and they likely use seasonal cues (big water changes, temperature shifts, conductivity changes, and specific spawning sites) that are hard to mimic reliably.

If you want to take a swing at it, focus on conditioning and giving them a setup that could plausibly work: a big tank, very clean water, heavy feeding on worms and frozen foods, and a rainy-season style routine with larger, slightly cooler water changes. Even then, don't be surprised if nothing happens.

Common problems to watch for

Most issues with this fish come down to stress, injuries, or starvation early on. If you get them eating and keep the tank stable, they can be hardy, but they don't forgive sloppy starts.

• Refusing food: very common in new arrivals. Try live blackworms or earthworm pieces, feed after dark, and reduce foot traffic around the tank for a week or two.
• Hiding nonstop: usually too much light, not enough cover, or boisterous tankmates. Add floaters, add wood, and calm the tank down.
• Mouth and chin abrasions: rough substrate/decor, or they spook and slam into things. Switch to sand and smooth hardscape.
• Ich and external parasites: wild-caught fish can bring baggage. Quarantine if you can, and pick treatments carefully (avoid copper-heavy meds).
• Skin infections after scrapes: keep water clean and address the cause of the injury. They heal, but they need low stress and good water.

One last real-world tip: keep a tight lid. They don't always jump, but a startled elephantfish is a missile, and they spook at night when you least expect it.