Steatocranus Explained

Steatocranus is a genus of small rheophilic cichlids mostly native to the Congo River Basin in DR Congo/Congo Brazzaville, although one species, S. irvinei, is restricted to the Volta River in Ghana and Burkino Faso, and it belongs in a separate genus.^[1] There are also at least 10 undescribed species in the Congo River basin awaiting scientific description.^{[2] [3]}

The fish in this genus all have relatively reduced swim bladder function. The name Steatocranus refers to the fatty deposit on the forehead of most species.

Two species, S. casuarius (also known as the lionhead or buffalohead cichlid) and S. tinanti are relatively common in the aquarium trade.

As for other cichlids brood care is highly developed and both sexes are involved in raising the young. All Steatocranus species are secretive cave spawners and form monogamous pairs for breeding. The female is more actively involved in fry raising, while the male is primarily concerned with territorial defence.

Species

There are currently ten recognized species in this genus,^[4] but S. irvinei belongs elsewhere;^[1] in 2019 it was proposed to move it to its own genus, Paragobiocichla.^[5]

• Steatocranus bleheri M. K. Meyer, 1993
• Steatocranus casuarius Poll, 1939 (Lionhead cichlid)
• Steatocranus gibbiceps Boulenger, 1899
• Steatocranus glaber T. R. Roberts & D. J. Stewart, 1976
• Steatocranus irvinei (Trewavas, 1943)
• Steatocranus masalamasoso Zamba et al., 2022
• Steatocranus mpozoensis T. R. Roberts & D. J. Stewart, 1976
• Steatocranus rouxi (Pellegrin, 1928)
• Steatocranus tinanti (Poll, 1939)
• Steatocranus ubanguiensis T. R. Roberts & D. J. Stewart, 1976

Notes and References

1. Dunz, A.R., and Schliewen, U.K. (2013). Molecular phylogeny and revised classification of the haplotilapiine cichlid fishes formerly referred to as “Tilapia”. Molecular Phylogenetics and Evolution, online 29 March 2013.
2. Schwarzer, J. . B. Misof . S.N. Ifuta . U.K. Schliewen . 2011 . Time and Origin of Cichlid Colonization of the Lower Congo Rapids . PLOS ONE . 6 . 7 . e22380 . 10.1371/journal.pone.0022380 . 21799840 . 3140524 . 2011PLoSO...622380S . free .
3. Schwarzer, J. . B. Misof . U.K. Schliewen . 2011 . Speciation within genomic networks: a case study based on Steatocranus cichlids of the lower Congo rapids . Journal of Evolutionary Biology . 25 . 1 . 138–148 . 10.1111/j.1420-9101.2011.02409.x . 22070232 . 205433610 . free .
4. Zamba, A.I.. J.D. Weiss. V. Mamonekene. U.K. Schliewen. E.J.W.M.N. Vreven. 2022. Steatocranus masalamasoso, a new species of lionhead cichlid from the Léfini River basin, Congo basin, Africa (Teleostei: Cichlidae). Ichthyological Exploration of Freshwaters. in press. 10.23788/IEF-1130.
5. Weiss, J.D. . F.D.B. Schedel . A.I. Zamba . E.J.W.M.N. Vreven . U.K. Schliewen . 2019 . Paragobiocichla, a new genus name for Gobiochromis irvinei Trewavas, 1943 (Teleostei, Cichlidae) . Spixiana . 42 . 1 . 133–139 .