Cobalt Blue Zebra
Metriaclima callainos
Cichlidae
About
The cobalt blue zebra is a striking mbuna from the rocky shores of Lake Malawi, prized for the brilliant, near-solid metallic blue that both sexes carry into adulthood. Reaching around 13 cm, it is a bold, active grazer that scrapes aufwuchs from sunlit boulders but is also pugnacious and territorial, so it needs a spacious tank of hard, alkaline Rift Lake water broken up by heavy rockwork.
Care
Keep in hard, alkaline water (pH 7.8-8.5) over sand with abundant rockwork in a tank of 200 L or more. Best as a harem of one male with several females; aggressive and territorial, so choose sturdy Malawi mbuna tankmates and avoid peaceful community fish.
Diet
Herbivorous aufwuchs grazer; feed spirulina- and vegetable-based foods with blanched greens. Strictly limit protein-rich foods to prevent Malawi bloat.
Tankmate compatibility
Possible with care (153)
Avoid (118)
Computed by the AquaSage engine for a spacious reference tank — always check the full verdict for your exact setup in the calculator.
Telling males from females
What works for this species, most reliable first.
- VentingStrong · only on a mature fish, easiest when she is in breeding condition
The method breeders use when the answer has to be right. Hold the fish upside down in a wet hand or soft net and look at the two openings ahead of the anal fin. The forward one is the anus; the one behind it is what you are reading.
- Egg spotsA hint only · from about 6 months
The yellow or orange ocelli on the anal fin of Malawi cichlids, traditionally explained as a lure that draws the female into mouthing them, fertilising the eggs she is already holding.
- Adult sizeA hint only · only across animals of the same age
In many cichlids, catfish and loaches one sex simply grows larger — usually the male, though there are well-known reversals.
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Frequently asked questions
- What tank size does a Cobalt Blue Zebra need?
- A Cobalt Blue Zebra needs an aquarium of at least 200 litres (52.8 US gallons) with a footprint at least 120 cm (47.2 in) long — for this species, swimming length matters as much as raw volume.
- What water parameters does a Cobalt Blue Zebra need?
- Cobalt Blue Zebra does best at 24–28 °C (75.2–82.4 °F), pH 7.6–8.8 and a general hardness of 8–25 °dGH.
- What group size does a Cobalt Blue Zebra need?
- Cobalt Blue Zebra is a social species — keep a group of at least 4 so natural behaviour emerges and stress stays low.
- Is the Cobalt Blue Zebra suitable for beginners?
- Cobalt Blue Zebra sits in the middle of the difficulty scale — manageable for a careful beginner who has done the reading, but it has specific needs worth researching first.