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Churchill mormyrid

Petrocephalus simus

Also known as Simus baby whale, Dorsal band whale

FreshwaterFish

Churchill mormyrid (Petrocephalus simus)

Care at a glance

Temperature
75–82°F
24–28°C
pH
6.0–7.5
Adult size
4.7 in
12 cm
Minimum tank
42 gal
160 L
Temperament
Mostly peaceful
Social behavior
Solitary
Tankmates
With caution
Swim level
Bottom
Diet
Carnivore
Difficulty
Difficult
Breeding
No record
Rarity
Rare
Family
Mormyridae
Origin
Congo basin

Overview

The Churchill mormyrid is a small, blunt-faced elephantfish that is nocturnal, shy and electrically sensitive. It needs an experienced keeper.

Did you know

Churchill mormyrids that fight in small numbers settle into calm, coordinated schools in groups of ten or more. Few aquarists have the space to use that switch.

Caring for the Churchill mormyrid

Give a single Churchill mormyrid a tank of at least 42 gal (160 L). Set it up with a soft sand bed, driftwood and other cover, and low lighting. All of these help this timid, night-active fish settle.

Keep the water warm and soft to neutral, at 75 to 82°F (24 to 28°C) and a pH of 6.0 to 7.5. Hold conditions very steady, since elephantfishes react badly to swings in quality and to many medications. Feed small meaty foods such as bloodworm and blackworm after dark.

Keep it singly. Some of its relatives shoal, but in the small groups a tank usually allows, it turns aggressive toward its own kind. Choose tank mates with caution, picking calm, similarly sized fish that will not outcompete it. Breeding is not recorded in aquaria.

Good to know

The Churchill mormyrid belongs to the elephantfish family Mormyridae. It has the blunt, rounded head that gives Petrocephalus the trade name churchill. Instead of a trunk it has a short, simple mouth, and it senses its surroundings with a weak electric organ discharge from the tail. It is also sold as the Simus baby whale or dorsal band whale.

In the wild

The Churchill mormyrid is widespread in the Congo basin. It lives over sandy shallows in warm, softly flowing water.

Common questions

What size tank does a Churchill mormyrid need?

A Churchill mormyrid needs at least 42 gal (160 L). It spends most of its time in the bottom.

What temperature and pH does a Churchill mormyrid need?

A Churchill mormyrid is comfortable at 75–82°F (24–28°C) with a pH of 6.0–7.5.

What does a Churchill mormyrid eat?

A Churchill mormyrid eats small meaty foods such as bloodworm and blackworm. Offer them after dark, when it is active.

How big does a Churchill mormyrid get?

An adult Churchill mormyrid reaches about 4.7 in (12 cm).

Related species