TankBud

Ansorge's bichir

Polypterus ansorgii

Also known as Guinean bichir

FreshwaterFish

Ansorge's bichir (Polypterus ansorgii)

Care at a glance

Temperature
75–82°F
24–28°C
pH
6.2–7.8
Adult size
15.7 in
40 cm
Minimum tank
119 gal
450 L
Temperament
Mostly peaceful
Social behavior
Solitary
Tankmates
With caution
Swim level
Bottom
Diet
Carnivore
Difficulty
Medium
Breeding
Egg scatterer
Rarity
Rare
Family
Polypteridae
Origin
Upper Guinea rivers, West Africa

Overview

Ansorge's bichir is a rare West African oddball, a nocturnal predator for the bottom of a big tank. It suits a keeper with some experience.

Did you know

Ansorge's bichir is a fish keepers argued over sight unseen. It is one of the rarest bichirs in the trade. It has been exported so seldom that for years it was known mostly from museum specimens rather than living examples.

Caring for the Ansorge's bichir

Ansorge's bichir needs a big footprint of at least 119 gal (450 L), and ideally more. Give it a sand or fine-gravel floor, driftwood, rockwork and shade from tall or floating plants. Fit a tight, weighted lid, because bichirs climb out.

Keep the water soft to medium, slightly acidic to slightly alkaline, at a pH of 6.2 to 7.8. Hold it warm at 75 to 82°F (24 to 28°C) with gentle flow, and use subdued lighting to bring this nocturnal fish out. Feed meaty foods such as earthworms, prawn, mussel and sinking carnivore pellets in the evening.

Ansorge's bichir is a lurk-and-lunge predator that patrols the bottom and will eat any tank mate small enough to swallow. Keep it on its own or only with robust fish too large to become a meal, never with small community fish.

Its breeding is not recorded in home aquariums. Like its kin, it would scatter eggs among plants rather than guard a nest.

Good to know

Polypterus ansorgii is a bichir in the family Polypteridae, an ancient line of ray-finned fishes sheathed in hard, glossy scales. A 2019 revision of the family measured preserved specimens to 24.6 cm and recorded one aquarium fish at 37.1 cm. That is why a planning size of about 15.7 in (40 cm) is safer than the lower figures often quoted.

In the wild

Ansorge's bichir comes from forest rivers of Guinea and Guinea-Bissau in Upper Guinea, West Africa. These are slow, shaded, tannin-stained waters over soft bottoms.

Common questions

What size tank does an Ansorge's bichir need?

An Ansorge's bichir needs at least 119 gal (450 L). It spends most of its time in the bottom.

What temperature and pH does an Ansorge's bichir need?

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

What does an Ansorge's bichir eat?

An Ansorge's bichir eats meaty foods such as earthworms, prawn, mussel and sinking carnivore pellets, fed in the evening. It will also eat any tank mate small enough to swallow.

How big does an Ansorge's bichir get?

An adult Ansorge's bichir reaches about 15.7 in (40 cm).

How does an Ansorge's bichir breed?

Ansorge's bichir would scatter its eggs among plants, like its kin, rather than guard a nest. Its breeding has not been recorded in home aquariums.

Related species