Gymnallabes nops
Roberts and Stewart 1976
| ORDER | SUB-ORDER | FAMILY |
|---|---|---|
| Siluriformes | Siluroidei | Clariidae |
Synonyms
None.
Country
Lower Congo River: freshwaterTypes
Only a Holotype has been assigned: MCZ 50298.
Distribution
Lower Congo River, near Tadi, Democratic Republic of Congo (5°14'S, 13°56'E).
Systematics
There are two species in the genus: Gymnallabes typus Günther 1867 and Gymnallabes nops Roberts and Stewart 1976.
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:
Clariidae
Channallabes apus (Günther 1873) Teugels 1986
Dolichallabes microphthalmus Poll 1942
Gymnallabes nops Roberts and Stewart 1976
Platyallabes tihoni (Poll 1944) Poll 1977
Claroteidae
Notoglanidium pallidum Roberts and Stewart 1976
Mastacembelidae
Mastacembelus aviceps Roberts and Stewart 1976
Mastacembelus brichardi (Poll 1958) Vreven 2005
Mastacembelus crassus Roberts and Stewart 1976
Mastacembelus latens Roberts and Stewart 1976
Cichlidae
Lamprologus lethops Roberts and Stewart 1976
Mormyridae
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. Gymnallabes nops . The IUCN Red List of Threatened Species 2010: e.T182090A7793310. https://dx.doi.org/10.2305/IUCN.UK.2010-3.RLTS.T182090A7793310.en. Downloaded on 17 March 2020.
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
Melanie Stiassny video presentation on the Congo River fishes
Gymnallabes typus Genbank mitochondrial cytochrome b (1) (Hardman 2005)
Gymnallabes typus Genbank mitochondrial cytochrome b (2) (Agnese and Teugels 2005)
Gymnallabes typus Genbank 18S RNA (Jansen et al. 2006)
Key References
- Roberts, T.R. and Stewart, D.J. (1976)
- Poll, M. (1977)
- Cabuy, E., Adriaens, D., Verraes, W. and Teugels, G.G. (1999)
- Huysentruyt, F., Adriaens, D., Teugels, G.G., Devaere, S., Herrel, A., Verraes, W. and Aerts, P. (2004)
- Devaere, S., Adriaens, D., Teugels, G.G., De Clerck, N.M. and Postnov, A.A. (2005)
- Jansen, G., Devaere, S., Weekers, P.H.H. and Adriaens, D. (2006)
- Stiassny, M.L.J., Monsembula Iyaba, R.J.C., Liyandja, T., Mbimbi Mayi Munene, J.J., Yoko, M., and Alter, E. (2018)
- Stiassny, M.L.J. (2019)
- Elbein, A. (2020)
| 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 |
| Poll, M. | Journal Article | 1977 | Les genres nouveaux Platyallabes et Platyclarias comparés au genre Gymnallabes Gthr. Synopsis nouveau des genres de Clariidae |
| Cabuy, E., Adriaens, D., Verraes, W. and Teugels, G.G. | Journal Article | 1999 | Comparative study on the cranial morphology of Gymnallabes typus (Siluriformes: Clariidae) and their less anguilliform relatives, Clariallabes melas and Clarias gariepinus |
| 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., Adriaens, D., Teugels, G.G., De Clerck, N.M. and Postnov, A.A. | Journal Article | 2005 | Skeletal morphology of the holotype of Gymnallabes nops Roberts & Stewart, 1976, using micro CT-scanning |
| 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 |
| 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 |
