The "Cobalt Blue Zebra" is one of the dozens of other Pseudotropheus Zebras, which have recently been reclassified and given their own genus: Metriaclima. There are three strains of M. callainos: "Cobalt Blue," "Pearl Zebra," and OB. This male pictured below is of the "Cobalt Blue" morph. Males have a soft fluorescent blue ground color, without any vertical bars, and have ~5 eggs spots on their anal fin. Females are a little lighter shade of blue, almost grayish-blue. This species is often confused with Metriaclima benetos and males of the species Metriaclima estherae "Red Zebra" because of their identical coloring and similar body shape. The "Pearl Zebra" is characterized by both males and females having a pearl white color, while the OB morph has black blotches on a pink-blue body.

Adult males reach lengths of 10-12 cm (4-5 in.); females are a little smaller than males. They are principally vegetarians, needing lots of vegetable matter in their diet. This mbuna does best in a tank 55-gallons or larger. In the wild, they are found in rocky habitats at depths between 1 and 25 meters near the northwest coast of Lake Malawi, from Kande Island to Ngara and have also been found along the northeast coast between Ikombe and the Ruhuhu River.