Scientists have described a new genus and species of cichlid fish from central Africa.
Publishing their results in a recent issue of the journal American Museum Novitates, Melanie Stiassny and Ulrich Schliewen describe a new genus, Congochromis, for the members of the Nanochromis squamiceps group.
They also describe a new species from the upper Congo River drainage, Congochromis pugnatus, in the study.
In an earlier study, Stiassny and Schliewen divided Nanochromis into two species groups: the N. nudiceps and N. squamiceps groups.
The Nanochromis nudiceps group is retained in Nanochromis and the latter, now named Congochromis. The genus is named after the Congo River drainage and is distinguished from other cichlids in the number of laterosensory pores in the bones of the jaw and suspensorium.
Congochromis is distinguished from Nanochromis in having only the last three to five pored scales of the upper lateral line contiguous with the dorsal-fin base, fully scaled nape, and partially scaled chest and cheek, jaw teeth relatively robust, unicuspid and not closely spaced, and the presence of a small, supraneural bone.
The new species, Congochromis pugnatus, is distinguished from other members of the genus in having a strongly inclined lower jaw, expanded cheek musculature, and a unique caudal skeleton.
The first two features give the species a heavy-jawed pugnacious look, from which its name, which comes from the Latin pugno, meaning to fight, is derived.
There are three other species of Congochromis: C. squamiceps from the central Congo River drainage, C. dimidiatus from the central Congo River drainage and C. sabinae from the Congo and Ogowe river drainages.
The related parilus, transvestitus, minor, consortus and splendens remain in the genus Nanochromis. A number of other apparently undescribed species are known to exist in the wild and are kept in aquaria. It is not yet known which of the two genera these fall into.
For more information, see the paper: Stiassny, MLJ & UK Schliewen (2007) Congochromis, a new cichlid genus (Teleostei: Cichlidae) from Central Africa, with the description of a new species from the Upper Congo River, Democratic Republic of Congo. American Museum Novitates 3576, 1"14.