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Fallax killifish

Fundulopanchax fallax

Also known as CL 98 killi, Deceptive killifish

FreshwaterFish

Fallax killifish (Fundulopanchax fallax)

Care at a glance

Temperature
68–77°F
20–25°C
pH
5.5–7.0
Adult size
3.5 in
9 cm
Minimum tank
14 gal
54 L
Temperament
Mostly peaceful
Social behavior
Social
Swim level
Middle
Difficulty
Medium
Breeding
Egg burier · Medium
Rarity
Rare
Family
Nothobranchiidae
Origin
Coastal Cameroon

Overview

The Fallax killifish is a striking, mostly peaceful killi for a dim, planted species tank. It is moderately demanding to keep.

Did you know

The species name fallax is Latin and means deceiver. The fish was misidentified so often that being hard to tell apart became part of its formal description.

Caring for the Fallax killifish

A pair of Fallax killifish needs a tank of at least 14 gal (54 L). A harem of this big, active fish appreciates considerably more room. Give it a dim, planted tank with a dark base, wood and leaf litter, and keep the flow gentle. It is a strong jumper, so fit a tight cover.

Soft, acidic to neutral water suits it, at a pH of 5.5 to 7.0 and 68 to 77°F (20 to 25°C). Top up the tannins with leaves or peat to hold the stained look it lives in. Feed it well on meaty live and frozen foods such as bloodworm, brine shrimp, daphnia and chopped foods, plus some dry food.

Keep a single pair, or a harem of one male to two or more females. It swims through the middle and lower water. It is mostly peaceful for its size, but it may eat much smaller fish. Keep it in a species tank or with calm, similar-sized company.

The Fallax killifish is a semi-annual soil spawner. Its eggs are buried and given a damp rest before hatching, a routine that puts breeding at a moderate level.

Good to know

Fundulopanchax fallax is a member of the family Nothobranchiidae. It is one of the bigger killifish a hobbyist is likely to keep.

In the wild

The Fallax killifish lives in swampy, slow-moving streams along the coast of Cameroon. The water there is soft and tea-dark, shaded by forest and littered with leaves.

Weekly picks

Tank mates

The Fallax killifish is a mostly peaceful, social species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator

Common questions

What size tank does a Fallax killifish need?

A Fallax killifish needs at least 14 gal (54 L). It spends most of its time in the middle.

What temperature and pH does a Fallax killifish need?

A Fallax killifish is comfortable at 68–77°F (20–25°C) with a pH of 5.5–7.0.

What does a Fallax killifish eat?

A Fallax killifish eats meaty live and frozen foods such as bloodworm, brine shrimp, daphnia and chopped foods, plus some dry food. It may also eat much smaller fish.

How big does a Fallax killifish get?

An adult Fallax killifish reaches about 3.5 in (9 cm).

How does a Fallax killifish breed?

The Fallax killifish is a semi-annual soil spawner whose eggs are buried. They get a damp rest before hatching, a routine that puts breeding at a moderate level.

Related species