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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
Tankmates with caution
Swim level
Bottom
Difficulty
Difficult
Breeding
No record
Rarity
Rare
Origin
Congo basin
Family
Polypteridae

Overview

Weeks' bichir is a big, broad-headed, placid-until-fed predator that stays calm with tankmates too large to eat and swallows anything smaller, so house it alone or with equally large, sturdy fish. At over half a meter it needs a large tank with a generous floor, at least 600 liters. It is a nocturnal ambusher that takes meaty foods such as whole prawn, mussel, earthworms and large sinking carnivore items, and feeding with tongs makes for good viewing. Give it a soft sand bottom, wood and rock cover, and a heavy, tight lid, since large bichirs still climb out.

In the wild

It lives in the slow, warm waters of the central Congo basin, over soft bottoms with wood and vegetation. Recreate that with a sand floor, big driftwood, rock caves and open resting space, with gentle to moderate flow. Keep it warm at 24 to 28 C and from slightly acidic to slightly alkaline, about pH 6.2 to 7.8. Subdued lighting and cover help this heavy-bodied, nocturnal fish settle.

Good to know

Polypterus weeksii, the mottled bichir, is a member of the family Polypteridae reaching about 54 cm, broad-skulled with bold dark markings on a grey-green body. It was described in 1898 by George Boulenger. Its home breeding is not recorded; in the wild bichirs are plant spawners that scatter adhesive eggs and give no parental care.

Did you know

Its name came from a mission station. Polypterus weeksii honours John Weeks, a Baptist missionary and diarist who collected the first specimen at his post on the upper Congo in the 1890s, sending it on to be described in London.

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 do Weeks' bichir need?

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

How big do Weeks' bichir get?

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

Where to buy

Some links may not be the exact species or variety.

…or ask your local fish store.

Appears in

Freshwater fish · Advanced fish · Bottom dwellers · Monster fish

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