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Monoculus peacock bass

Cichla monoculus

Also known as Popoca peacock bass, Mono peacock bass

FreshwaterFish

Monoculus peacock bass (Cichla monoculus)

Care at a glance

Temperature
77–86°F
25–30°C
pH
6.0–7.5
Adult size
27.6 in
70 cm
Minimum tank
898 gal
3,400 L
Temperament
Aggressive
Social behavior
Solitary
Tankmates
With caution
Swim level
Middle
Diet
Carnivore
Difficulty
Difficult
Breeding
Substrate spawner · Hard
Rarity
Rare
Family
Cichlidae
Origin
Amazon lowlands

Overview

The Monoculus peacock bass is a pond-scale predator that outgrows almost every home aquarium. It is a fish for experienced keepers, and a decades-long commitment.

Did you know

The dark eyespot near the tail of the Monoculus peacock bass is thought to work as a decoy. It mimics the real eye and may draw fin-nipping attackers toward the tail end instead of the head.

Caring for the Monoculus peacock bass

Keep a single Monoculus peacock bass on its own, in at least 898 gal (3,400 L), which is really an indoor pond. Provide a large open swimming area over sand, with big pieces of wood for structure.

Give it warm, soft to neutral water at 77 to 86°F (25 to 30°C) and a pH of 6.0 to 7.5. It takes a lower pH well. Run heavy mechanical and biological filtration and current, since a fish this size produces a heavy load of waste.

Feed meaty foods such as whole fish, prawn and large sinking pellets. It is a strong, active swimmer that patrols the middle water and will eat any tank mate it can fit in its mouth. Companions have to be large, fast and chosen with great care, if you keep any at all.

Like other peacock bass, it is a biparental substrate spawner that cleans a site, lays a large clutch and guards the fry fiercely. Breeding one indoors is hard, simply because of the space a pair demands.

Good to know

Cichla monoculus belongs to the cichlid family and is a giant among aquarium fish. It was described by Agassiz in 1831, and its name means one-eyed, for the single large eyespot at the base of the tail.

In the wild

Cichla monoculus ranges through the warm lowland Amazon, hunting in lakes, lagoons and slow channels. Its natural water is often quite acidic.

Common questions

What size tank does a Monoculus peacock bass need?

A Monoculus peacock bass needs at least 898 gal (3,400 L). It spends most of its time in the middle.

What temperature and pH does a Monoculus peacock bass need?

A Monoculus peacock bass is comfortable at 77–86°F (25–30°C) with a pH of 6.0–7.5.

What does a Monoculus peacock bass eat?

A Monoculus peacock bass is a predator that eats meaty foods, such as whole fish, prawn and large sinking pellets.

How big does a Monoculus peacock bass get?

An adult Monoculus peacock bass reaches about 27.6 in (70 cm).

How does a Monoculus peacock bass breed?

Monoculus peacock bass are biparental substrate spawners that clean a site, lay a large clutch and guard the fry fiercely. Breeding them indoors is hard, simply because of the space a pair demands.

Related species