The holotype of C. robustus was collected in 1954. © A. Lamboj

The African cichlid genus Congochromis was erected in 2007 to accommodate four species of dwarf cichlid of which three, C. dimidiatus, C. sabinae, and C. squamiceps, are former members of Nanochromis. They’re diagnosable by a combination of morphological and osteological characters, and all are endemic to the Congo River basin.

Within the family Cichlidae Congochromis is a member of the informally-recognised chromidotilapiine clade and is most closely-related to Nanochromis. Unpublished DNA analyses mentioned by Stiassny and Schliewen (2007) also placed Chromidotilapia schoutedeni (Poll and Thys van den Audenaerde, 1967) and Limbochromis robertsi (Thys van den Audenaerde and Loiselle, 1971) as sister species. These were unexpected results and further work is in progress to more fully understand the relationships between members of this clade.

The new species is descibed as C. robustus Lamboj 2012, the name referring to its relatively large size and robust body shape. The largest specimen in the type series measures 75.6 mm SL, i.e., more than 20 mm longer than any congener. It’s known only from a single locality in the Kisangani area of the Central Congo basin and was in fact described from preserved material collected by Gosse in 1954 but which had not previously been identified as a new taxon. Live colour pattern is currently unknown.

For further information please refer to the full paper, of which the abstract is open access: Lamboj, A. 2012. A new species of the genus Congochromis (Cichlidae) from the Central Congo basin. Cybium 36(2): 349-352.

Thanks to Anton Lamboj for supplying the image of the holotype.