TankBud

Eel mormyrid

Isichthys henryi

Also known as Henry's mormyrid

FreshwaterFish

Eel mormyrid (Isichthys henryi)

Care at a glance

Temperature
73–82°F
23–28°C
pH
6.5–7.5
Adult size
11.4 in
29 cm
Minimum tank
79 gal
300 L
Temperament
Mostly peaceful
Social behavior
Solitary
Tankmates
With caution
Swim level
Bottom
Diet
Carnivore
Difficulty
Medium
Breeding
No record
Rarity
Rare
Family
Mormyridae
Origin
Coastal rivers from Guinea to Gabon, West Africa

Overview

The eel mormyrid is a slender elephantfish that glides slowly through cover in a dim tank. It is a step up from the easiest fish.

Did you know

The eel mormyrid's long dorsal and anal fins run down the rear half of its body and nearly mirror each other. They let it swim backward almost as smoothly as forward. Elephantfishes use that trick to keep the electric-sensing snout aimed while reversing out of tight cover.

Caring for the eel mormyrid

An eel mormyrid needs a tank of at least 79 gal (300 L) with a soft sand floor. Add dense, tangled wood and root cover for it to thread through, with low light and a gentle flow.

Keep the water warm and neutral, at 73 to 82°F (23 to 28°C) and a pH of 6.5 to 7.5. Hold it very steady, as elephantfishes are sensitive to poor or fluctuating conditions. Feed meaty foods such as bloodworm, blackworm and small earthworm in the evening.

Keep it singly, since it is not reliably peaceful with its own kind. It is a slow, deliberate feeder, so choose tank mates with caution: calm, similarly sized fish that will not outcompete it. Its breeding is not documented in captivity.

Good to know

The eel mormyrid is the only species in its genus, an elephantfish of the family Mormyridae with an elongated, almost eel-like body. It senses its surroundings with a weak electric organ discharge from the tail. It is also known as Henry's mormyrid.

In the wild

The eel mormyrid ranges through the coastal rivers of West and Central Africa, from Guinea and Liberia through Cameroon and Gabon. It lives among submerged roots and wood in slow, shaded water.

Common questions

What size tank does an eel mormyrid need?

An eel mormyrid needs at least 79 gal (300 L). It spends most of its time in the bottom.

What temperature and pH does an eel mormyrid need?

An eel mormyrid is comfortable at 73–82°F (23–28°C) with a pH of 6.5–7.5.

What does an eel mormyrid eat?

An eel mormyrid eats meaty foods such as bloodworm, blackworm and small earthworm. Feed it in the evening, and keep faster tank mates from beating it to the food.

How big does an eel mormyrid get?

An adult eel mormyrid reaches about 11.4 in (29 cm).

Related species