Dolichallabes microphthalmus

Poll 1942





Lower Congo River: freshwater


Holotype: MRAC 44655 adult male, 229 mm SL.

Paratypes: MRAC 44656-59 (196–210 mm), MRAC 62407 (188 mm SL).


Dolichallabes microphthalmus is the only species in the genus.

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. Dolichallabes microphthalmus. The IUCN Red List of Threatened Species 2010: e.T182410A7880107. Downloaded on 20 March 2020.

Museum Holdings

MRAC 57662, 196 mm SL

MRAC 18850, 90 mm SL

MRAC 101843, 149 mm SL

MRAC 176123–124 68 mm SL

MRAC 79093, 134 mm SL

MRAC 93774, 66 mm SL

MRAC 79258–260 85–126 mm SL

MRAC 78808–810 99–110 mm SL

MRAC 96672 110 mm SL

MRAC 66721, 97 mm SL.

Details from Daevere et al. (2004).

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

Genbank mitochondrial cytochrome b (Wright and Bailey 2012)

Key References

Poll, M. Journal Article 1942 Notes sue l'osteologie de Dolichallabes microphalmus Poll et remarques sur l'evolution des Clariidae
Poll, M. Journal Article 1942 Description d'un genre nouveau de Clariidae originaire du Congo belge
Adriaens, D., Devaere, S., Teugels, G.G., Dekegel, B. and Verraes, W Journal Article 2002 Intraspecific variation in limblessness in vertebrates: a unique example of microevolution
Huysentruyt, F., Adriaens, D., Teugels, G.G., Devaere, S., Herrel, A., Verraes, W. and Aerts, P. Journal Article 2004 Diet composition in relation to morphology in some African anguilliform clariid catfishes
Devaere, S, Teugels, G, Adriaens, D, Huysentruyt, F. and Verraes, W. Journal Article 2004 Redescription of Dolichallabes microphthalmus (Poll, 1942) (Siluriformes: Clariidae)
De Schepper, N; Adriaens, D; Teugels, GG; et al. Journal Article 2004 Intraspecific variation in the postcranial skeleton morphology in African clariids: a case study of extreme phenotypic plasticity
Jansen, G., Devaere, S., Weekers, P.H.H. and Adriaens, D. Journal Article 2006 Phylogenetic relationships and divergence time estimate of African anguilliform catfish (Siluriformes: Clariidae) inferred from ribosomal gene and spacer sequences
Alter, S.E., Brown, B. and Stiassny, M.L.J. Journal Article 2015 Molecular phylogenetics reveals convergent evolution in lower Congo River spiny eels
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.
Harrison, I.J., Brummett, R. and Stiassny, M.L.J. Book Section 2016 Congo River basin
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
Aardema, M.L., Stiassny, M.L.J. and Alter, S.E. Journal Article 2020 Genomic analysis of the only blind Cichlid reveals extensive inactivation in eye and pigment formation genes
Stiassny, M.L. and Alter, S.E. Book Section 2021 Life in the fast lane: diversity, ecology, and speciation of cichlids in the lower Congo River