Cobalt Blue Zebra

Metriaclima callainos

Cichlids - African
Reviewed by Guidarium Editorial DeskUpdated May 3, 2026

A striking and highly active Mbuna cichlid endemic to the rocky shores of Lake Malawi. Known for its brilliant, solid cobalt blue coloration (though white morphs exist). Like most Mbuna, they are highly territorial, rock-grazing herbivores. They require an alkaline environment, a sandy substrate for digging, and extensive rockwork to establish territories. To manage aggression, they are best kept either in heavily populated, mixed all-male Mbuna tanks or in species harems (1 male to 3+ females).

Cobalt Blue Zebra At a Glance

Adult Size11 cm
Body ShapeFusiform
Growth RateModerate
TemperamentAggressive
Water TypeFreshwater Only
Flow PreferenceModerate
Waste OutputHigh
StockingFlexible

Cobalt Blue Zebra Tank Requirements

Minimum Volume200 L
Minimum Length120 cm
FlowModerate
Water TypeFreshwater Only
Must-Haves in the Tank
Sand (Sifters)
Stocking calculator

Will Cobalt Blue Zebra fit in your tank?

Care guides tell you what Cobalt Blue Zebra needs, the next question is whether your tank can safely provide it. Test Cobalt Blue Zebra against your tank size, maintenance needs, and the fish you already keep before you buy.

Cobalt Blue Zebra
Test in my tank

Cobalt Blue Zebra Water Parameters

Temperature2428°C
pH7.88.6
Hardness1025 dGH

Cobalt Blue Zebra Temperament & Compatibility

Aggression LevelAggressive
8/10
Where They Swim
Surface
Mid-level
Bottom
Stocking Guidelines
Keep at Least1 (solo is fine)
Max per TankNo limit
Can Live Alone?No — needs a group
Behavior Traits
Generally AggressiveAggressive to same species/look-alikesTerritorial (Defends specific area)Hyperactive / Fast SwimmerDigger (Disturbs Substrate)Plant Destroyer

Cobalt Blue Zebra Varieties

Each variety inherits the species defaults above. Only differences are highlighted.

Male (Cobalt Blue)

Brilliant solid cobalt blue with pronounced egg spots. Highly territorial, especially toward other males of the same or similar-looking species. Should be kept as the single male of its species in a community, or with a harem of females.

Differs in 2 traits from base species

Also known as: Dominant Male, Blue Mbuna

TemperamentAggressive
StockingSolo only

Female

Usually slightly smaller than males. While often similarly colored (blue or pale blue), they exhibit less dominant behavior. Essential for diffusing male aggression in breeding groups. Best kept in ratios of 3+ females per male.

Differs in 2 traits from base species

Also known as: Female Mbuna, Girl

Adult Size9.5 cm
TemperamentSemi-Aggressive

Pearl Zebra (White Morph)

A naturally occurring morph exhibiting a striking pearlescent white body instead of the typical cobalt blue. Their care, size, and aggressive temperament are identical to the standard blue variety.

Differs in 1 trait from base species

Also known as: Pearl Zebra, White Morph, Snow White

TemperamentAggressive

Cobalt Blue Zebra Care Guide Summary

The Cobalt Blue Zebra, scientifically known as Metriaclima callainos, belongs to the Cichlids - African family group. Adults reach a maximum size of approximately 11 cm and have a fusiform body shape with a moderate growth rate. Classified as aggressive, this species primarily occupies the mid-level and bottom zones of the aquarium and produces a high level of biological waste.

To thrive, the Cobalt Blue Zebra requires a freshwater only aquarium with a minimum volume of 200 litres and a tank length of at least 120 cm. Water temperature should be maintained between 24°C and 28°C, with a pH range of 7.88.6 and a general hardness of 1025 dGH. A moderate water flow is preferred.

Due to its specialist needs, the Cobalt Blue Zebra is best suited for fishkeepers who can provide a carefully planned setup. This species is available in 3 varieties: Male (Cobalt Blue), Female, and Pearl Zebra (White Morph). Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.

Cobalt Blue Zebra Habitat Setup

When setting up an aquarium for the Cobalt Blue Zebra, a moderate water flow best suits their natural preferences. Because this species occupies the mid-level and bottom zones, the aquarium layout should prioritise open swimming space in the centre of the tank for free movement and sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include a sand substrate to accommodate their sifting behaviour. Keepers should note that expect substrate disturbance, so lightweight décor should be secured and live planted layouts may be difficult to maintain, as this species tends to uproot or consume vegetation.

Cobalt Blue Zebra Compatibility Notes

Classified as aggressive, the Cobalt Blue Zebra is best kept in a small group for natural social behaviour. When choosing tankmates, conspecific aggression can be intense, especially in smaller tanks, territorial behaviour may cause issues if hiding spots or floor space are limited, and their energetic swimming style may stress more sedentary or timid species. Selecting tankmates that favour different water layers from the mid-level and bottom zones can help reduce competition and territorial overlap.

Who Cobalt Blue Zebra Is Actually For

Cobalt Blue Zebra is best for a fishkeeper who expects a species with attitude and plans the tank around that behavior and can provide someone who understands its individual space requirements. It makes the most sense for a hobbyist who will actually build around its needs, especially sand.

The most common mistake is treating Cobalt Blue Zebra like any other community fish and skipping the soft sand it needs to forage safely. Another frequent problem is forcing it into an over-busy community when it would do better with more room or more deliberate tankmate choices.

Cobalt Blue Zebra Recommended Tank Sizes

Standard aquarium sizes that meet the minimum volume and length requirements for Cobalt Blue Zebra.

Show 5 more tank sizes

Frequently Asked Questions About Cobalt Blue Zebra

How big does Cobalt Blue Zebra get?

Cobalt Blue Zebra (Metriaclima callainos) typically reaches a maximum adult size of approximately 11 cm. They have a fusiform body shape and a moderate growth rate.

What tank size does Cobalt Blue Zebra need?

A minimum aquarium volume of 200 litres and a tank length of at least 120 cm are recommended for Cobalt Blue Zebra. This ensures enough swimming space and helps maintain stable water conditions.

What water parameters does Cobalt Blue Zebra need?

Cobalt Blue Zebra thrives in freshwater only conditions with a temperature range of 24–28°C, a pH between 7.8 and 8.6, and a general hardness of 10–25 dGH. A moderate water flow is preferred.

Is Cobalt Blue Zebra peaceful or aggressive?

Cobalt Blue Zebra is classified as aggressive with an aggression score of 8 out of 10. Careful tankmate selection is essential to avoid conflict.

Can Cobalt Blue Zebra live alone?

No, Cobalt Blue Zebra should be kept in groups of at least 1 to reduce stress and encourage natural behaviour.

Does Cobalt Blue Zebra have any special tank requirements?

Yes. Cobalt Blue Zebra benefits from sand (sifters) in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 3, 2026
Last updated
May 3, 2026
Issues or corrections?
Contact the editorial team

Fish Similar to Cobalt Blue Zebra

Red Top Cobalt Cichlid

Metriaclima greshakei

Cichlids - African
13 cm Aggressive

An attractive and robust Mbuna cichlid native to the rocky shores of Lake Malawi. They are highly sexually dimorphic. Like most Mbuna, they require hard, alkaline water, intricate rockwork to establish territories, and a specialized herbivore-leaning diet to prevent digestive issues (Malawi bloat).

Socolofi Cichlid (Pseudotropheus Socolofi)

Chindongo socolofi

Cichlids - African
12 cm Aggressive

A stunning and highly active Mbuna cichlid endemic to Lake Malawi. Unusually for Mbuna, both males and females share the same striking powder blue coloration. Like most Mbuna, they are highly aggressive, territorial, and require a rock-filled aquarium with hard, alkaline water. They graze on algae (aufwuchs) in the wild and are prone to fatal 'Malawi bloat' if fed diets high in animal protein.

Electric Blue Johannii

Pseudotropheus johannii

Cichlids - African
10 cm Aggressive

An iconic Mbuna cichlid from Lake Malawi renowned for extreme sexual dimorphism. Males transform into a striking electric blue with dark navy horizontal stripes, while females and juveniles remain a vibrant yellow-orange. Like most Mbuna, they are highly aggressive, territorial, and require hard, alkaline water with extensive rockwork to form caves. They are avid diggers and will destroy most live plants.

Maingano Mbuna

Pseudotropheus cyaneorhabdos

Cichlids - African
10 cm Aggressive

A strikingly beautiful, highly active Mbuna from Lake Malawi. They feature dark blue bodies with vibrant light blue horizontal stripes. Unlike the closely related Johannii (where females are yellow/orange), both male and female Mainganos share this stunning blue coloration. They are fiercely territorial rock-dwellers that require hard, alkaline water, sandy substrates for digging, and a strict herbivorous/omnivorous diet to prevent Malawi bloat.

Red Zebra Cichlid (Cherry Red)

Metriaclima estherae

Cichlids - African
11 cm Aggressive

A highly popular and vibrant Mbuna cichlid from Lake Malawi. The 'Cherry Red' or Orange morph is a favorite for African Cichlid setups. They are rock-dwelling (Mbuna), highly territorial, and require a diet rich in vegetable matter (algae/spirulina) to avoid Malawi Bloat. Best kept in a harem ratio of 1 male to 3+ females.

Red Empress

Protomelas taeniolatus

Cichlids - African
15 cm Semi-Aggressive

A stunning and relatively peaceful Lake Malawi Haplochromine cichlid. Males develop breathtaking red and blue coloration, while females remain a camouflaged silvery-brown. Though considered a 'gentle Hap' compared to Mbuna, they are still large, active African Cichlids that require hard, alkaline water, plenty of swimming space, and rockwork.