TankBud

Weeks' bichir

Polypterus weeksii

Also known as Fat-headed bichir, Mottled bichir, Fat head bichir

FreshwaterFish

Weeks' bichir (Polypterus weeksii)
Stan Shebs · CC BY-SA 3.0

Care at a glance

Temperature
75–82°F
24–28°C
pH
6.2–7.8
Adult size
21.3 in
54 cm
Minimum tank
159 gal
600 L
Temperament
Mostly peaceful
Social behavior
Solitary
Tankmates
With caution
Swim level
Bottom
Diet
Carnivore
Difficulty
Difficult
Breeding
Egg scatterer
Rarity
Rare
Family
Polypteridae
Origin
Congo basin

Overview

Weeks' bichir is a big, broad-headed predator that stays placid until it is fed. It is a demanding fish for experienced keepers.

Did you know

Weeks' bichir got its name from a mission station. Polypterus weeksii honors John Weeks, a Baptist missionary and diarist. He collected the first specimen at his post on the upper Congo in the 1890s and sent it to London to be described.

Caring for the Weeks' bichir

Weeks' bichir needs a large tank with a generous floor, at least 159 gal (600 L). Give it a soft sand bottom, big driftwood, rock caves and open resting space. Fit a heavy, tight lid, since large bichirs still climb out.

Keep it warm at 75 to 82°F (24 to 28°C), with a slightly acidic to slightly alkaline pH of 6.2 to 7.8. Gentle to moderate flow suits it. Subdued lighting and cover help this heavy-bodied, nocturnal fish settle.

It is an ambusher that takes meaty foods such as whole prawn, mussel, earthworms and large sinking carnivore items. Feeding with tongs makes for good viewing.

Weeks' bichir stays calm with tank mates too large to eat but swallows anything smaller. House it alone or with equally large, sturdy fish. Its home breeding is not recorded. In the wild, bichirs are plant spawners that scatter adhesive eggs and give no parental care.

Good to know

Polypterus weeksii, the mottled bichir, is a member of the family Polypteridae. It has bold dark markings on a gray-green body. It was described in 1898 by George Boulenger.

In the wild

Weeks' bichir lives in the central Congo basin. Its home waters are slow and warm, over soft bottoms with wood and vegetation.

Common questions

What size tank does a Weeks' bichir need?

A Weeks' bichir needs at least 159 gal (600 L). It spends most of its time in the bottom.

What temperature and pH does a Weeks' bichir need?

A Weeks' bichir is comfortable at 75–82°F (24–28°C) with a pH of 6.2–7.8.

What does a Weeks' bichir eat?

A Weeks' bichir eats meaty foods such as whole prawn, mussel, earthworms and large sinking carnivore items. It will also swallow any tank mate small enough to eat.

How big does a Weeks' bichir get?

An adult Weeks' bichir reaches about 21.3 in (54 cm).

How does a Weeks' bichir breed?

Weeks' bichir has not been recorded breeding in home aquariums. In the wild, bichirs are plant spawners that scatter adhesive eggs and give no parental care.

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