Mastacembelus brichardi

(Poll 1958) Roberts and Stewart 1976

Mastacembelus brichardi
Masacembelus brichardi (Poll 1958). From Poll (1973)


Caecomastacembelus brichardi  Poll 1958


Lower Congo River: freshwater


Holotype: MRAC 118574. Paratypes: MRAC 118992-94.


All four species of Mastacembelus included in this list are troglomorphic Lower Congo River residents (Alter et al. 2015, Day et al. 2017). Phylogenetic studies by these authors have shown conclusively that the sister species of M. brichardi is the epigean and non-troglomorphic M. brachyrhinus Boulenger 1899 and that this pair are the furthest from the root of the Family and the latest to evolve. M. crassus and M. aviceps are each other’s sister species and the sister of this pair is the epigean and non-troglomorphic M. simbi Vreven and Stiassny 2009. Clearly the evolution of troglomorphy in the Lower Congo has occurred twice independently and is a clear case of convergent evolution. See Vreven (2005) for further phylogenetic information on the Family Mastacembelidae. M. latens was not available for these studies but is almost certainly a third instance of the evolution of troglomorphy.


Diversification dynamics of the African Mastacembelus radiation inferred using BAMM. Top: Phylorate plot shows speciation rate along each branch (‘linear’ plot); warmer colours indicate faster rates; scale bar represents speciation rate per Ma. Bottom: Evolutionary rate variation through time (RTT plot); shading denotes confidence on rate reconstructions at any point in time. [Figure 2 from Day et al 2017, used with permission].

Biological Notes

The lower Congo River, and especially the northern and southern rapids below Pool Malebo, are home to many endemic species (Roberts and Stewart 1976, Bailey 1986, Thieme et al. 2005, Mamonekene 2005, Alter et al. 2015, Alter et al. 2017, Stiassny 2016). In particular there are at least eleven species, in five Families, which exhibit the troglomorphic features of reduced eyes and pigment:


Channallabes apus (Günther 1873) Teugels 1986

Dolichallabes microphthalmus Poll 1942

Gymnallabes nops Roberts and Stewart 1976

Platyallabes tihoni (Poll 1944) Poll 1977


Notoglanidium pallidum Roberts and Stewart 1976


Mastacembelus aviceps Roberts and Stewart 1976

Mastacembelus brichardi (Poll 1958) Vreven 2005

Mastacembelus crassus Roberts and Stewart 1976

Mastacembelus latens Roberts and Stewart 1976


Lamprologus lethops Roberts and Stewart 1976


Stomatorhinus microps Boulenger 1898

These features probably evolved because these species live at depth within the rapids and spend their whole lives in permanent darkness, analagous to life in caves. The ocular and craniofacial anatomy of several of these species have been studied (Schobert et al. 2010, 2011, 2013) but almost nothing else is known about these animals.

Conservation Status


Moelants, T. 2010. Mastacembelus brichardi . The IUCN Red List of Threatened Species 2010: e.T182377A7872783. Downloaded on 17 March 2020.

Museum Holdings

AMNH7047 (Day et al. 2017)

Internet Resources

Main page for the Congo Project

Elizabeth Alter's work on Congo fishes

New York Times article with good photographs

Convergent evolution in the Congo rapids

A fish with the bends

Melanie Stiassny video presentation on the Congo River fishes

Video 1

Video 2


Key References

Poll, M. Journal Article 1958 Description d'un poisson aveugle nouveau du Congo belge, appartenant à la famille des Mastacembelidae
Poll, M. Journal Article 1959 Résultats scientifiques des missions zoologiques au Stanley Pool subsidiées par le Cemubac (Université Libre de Bruxelles) et la Musée Royal du Congo (1957-1958)
Poll, M. Journal Article 1973 Les yeux des poissons aveugles africains et de Caecomastacembelus brichardi Poll en particulier
Roberts, T.R. and Stewart, D.J. Journal Article 1976 An ecological and systematic survey of fishes in the rapids of the lower Zaire or Congo river
Travers, R.A. Journal Article 1984 A review of the Mastacembeloidei, a suborder of synbranchiform teleost fishes. Part II: Phylogenetic analysis
Travers, R.A. Journal Article 1984 A review of the Mastacembeloidei, a suborder of synbranchiform teleost fishes. Part I: Anatomical descriptions
Britz, R. Journal Article 1996 Ontogeny of ethmoidal region and hyopalatine arch in Macrognathus pancalus (Percomorpha,Mastacembeloidei), with critical remarks on mastacembeloid inter- and intrarelationships
Decu, V., Juberthie, C. and Tercafs, R. Book Section 2001 Republique Democratique Du Congo (ex-Zaire)
Vreven, E.J. Journal Article 2005 Mastacembelidae (Teleostei; Synbranchiformes) subfamily division and African generic division: an evaluation
Kish, P.E., Bohnsack, B.L., Gallina, D., Kasprick, D.S. and Kahana, A. Journal Article 2011 The eye as an organizer of craniofacial development
Schobert, C.S., Stiassny, M.L.J., Jeffery, W.D. and Dubielzig, R.R. Journal Article 2011 Comparative ocular anatomy In troglomorphic fish: Sensory compensation for reduced vision
Stiassny, M.L.J. and Alter, S.E. Journal Article 2015 Phylogenetics of Teleogramma, a riverine clade of African cichlid fishes, with a description of the deep-water molluskivore —Teleogramma obama — from the lower reaches of the middle Congo River.
Alter, S.E., Brown, B. and Stiassny, M.L.J. Journal Article 2015 Molecular phylogenetics reveals convergent evolution in lower Congo River spiny eels
Alter, S.E., Munshi-South, J. and Stiassny, M.L.J. Journal Article 2017 Genomewide SNP data reveal cryptic phylogeographic structure and microallopatric divergence in a rapids adapted clade of cichlids from the Congo River
Day, J.J., Fages, A., Brown, K.J., Vreven, E.J., Stiassny, M.L.J., Bills, R., Friel, J.P. and Ruber, L. Journal Article 2017 Multiple independent colonizations into the Congo Basin during the continental radiation of African Mastacembelus spiny eels
Stiassny, M.L.J., Monsembula Iyaba, R.J.C., Liyandja, T., Mbimbi Mayi Munene, J.J., Yoko, M., and Alter, E. Conference Paper 2018 The evolution of extreme phenotypic convergence across fish lineages in the hyper-diverse Lower Congo River
Stiassny, M.L.J. Journal Article 2019 Fishes in the lower Congo River An extreme case of species divergence and convergent evolution
Elbein, A. Web Page 2020 Earth’s deepest river conceals an evolutionary mystery
The head of Mastacembelus brichardi. From Poll (1973).
Photograph by Melanie Stiassny, used with permission