Marine and Freshwater Research Marine and Freshwater Research Society
Advances in the aquatic sciences

Adaptive radiation of Lake Tana’s (Ethiopia) Labeobarbus species flock (Pisces, Cyprinidae)

Martin de Graaf A C , Eshete Dejen B , Jan W. M. Osse A and Ferdinand A. Sibbing A D

A Experimental Zoology Group, Department of Animal Sciences, Wageningen University, Marijkeweg 40, 6709 PG Wageningen, The Netherlands.

B Amhara Region Agricultural Research Institute, PO Box 794, Bahar Dar, Ethiopia.

C Present address: Western Australia Marine and Fisheries Research Laboratories, PO Box 20, North Beach, WA 6920, Australia.

D Corresponding author. Email:

Marine and Freshwater Research 59(5) 391-407
Submitted: 29 June 2007  Accepted: 3 March 2008   Published: 6 June 2008


Studying species flocks (e.g. Darwin’s finches, Caribbean anoline lizards, East African cichlid fishes) has proven to be highly successful in understanding the forces driving speciation. The only known, intact species flock of cyprinid fishes, the 15 Labeobarbus species in Lake Tana (Ethiopia), includes eight piscivorous species. Piscivory is a rare specialisation among the highly successful (>2000 species) but mostly benthivorous Cyprinidae. The extent and mechanisms of diversification of this remarkable Labeobarbus species flock, particularly among the unexpected piscivorous species, are still largely unknown. In the present study we demonstrate that all 15 Labeobarbus species are segregated to a great extent along spatial, trophic and/or temporal dimensions. The spatial distribution, diet (prey species but not prey size), time of active feeding and predation techniques differed significantly among the eight piscivores. Lake Tana’s cyprinids displayed their retained potential for ecological diversification and speciation, including the uncommon specialisation of piscivory. The latter is probably a result of the absence of common African specialist piscivores in Lake Tana. We suggest that the evolution of Lake Tana’s Labeobarbus species flock at this stage is predominantly structured by ecological selection models. The labeobarbs most likely underwent sequential stages of radiation and speciation: habitat divergence followed by trophic divergence.

Additional keywords: diagnostic bones prey fish, ecological segregation, phylogenetic constraints, piscivory, sympatric evolution.


Banister K. E.1973A revision of the large Barbus (Pisces: Cyprinidae) of East and Central Africa: Studies on African Cyprinidae, part 2.Bulletin of the British Museum of Natural History (Zoology)26167180

Barel C. D. N.1982Towards a constructional morphology of cichlid fishes (Teleostei, Perciformes).Netherlands Journal of Zoology334357424

Boulenger G. A. (1911). ‘Freshwater Fishes of Africa.’ Vol II. (British Museum [Natural History]: London.)

Bouton N.Seehausen O.van Alphen J. J. M.1997Resource partitioning among rock-dwelling haplochromines (Pisces: Cichlidae) from Lake Victoria.Ecology of Freshwater Fish6225240doi:10.1111/J.1600-0633.1997.TB00165.X

Cooper D. W.1968The significance level in multiple tests made simultaneously.Heredity23614617doi:10.1038/HDY.1968.79

Danley P. D.Kocher T. D.2001Speciation in rapidly diverging systems: lessons from Lake Malawi.Molecular Ecology1010751086doi:10.1046/J.1365-294X.2001.01283.XPubmed Abstract

de Graaf M. (2003). Lake Tana’s piscivorous Barbus (Cyprinidae, Ethiopia): Ecology, Evolution, Exploitation. Ph.D. Thesis, Wageningen University, Wageningen.

de Graaf M.Dejen E.Sibbing F. A.Osse J. W. M.2000Barbus tanapelagius, a new species from Lake Tana (Ethiopia): its morphology and ecology.Environmental Biology of Fishes5919doi:10.1023/A:1007608208630

de Graaf M.Machiels M.Wudneh T.Sibbing F. A.2003Length at maturity and gillnet selectivity of Lake Tana’s Barbus species (Ethiopia): implications for management and conservation.Aquatic Ecosystem Health & Management63325336doi:10.1080/14634980301485

de Graaf M.Machiels M. A. M.Wudneh T.Sibbing F. A.2004Declining stocks of Lake Tana’s endemic Barbus species flock (Pisces; Cyprinidae): natural variation or human impact?Biological Conservation116277287doi:10.1016/S0006-3207(03)00198-8

de Graaf M.Nentwich E. D.Osse J. W. M.Sibbing F. A.2005Lacustrine spawning, a new reproductive strategy among ‘large’ African cyprinid fishes?Journal of Fish Biology6612141236doi:10.1111/J.0022-1112.2005.00671.X

de Graaf M.Samallo J.Megens H. J.Sibbing F. A.2007Evolutionary origin of Lake Tana’s (Ethiopia) small Barbus species: Indications of rapid ecological divergence and speciation.Animal Biology573948doi:10.1163/157075607780002069

Dejen E.Rutjes H. Graaf M.Nagelkerke L. A. J.Osse J. W. M.Sibbing F. A.2002The ‘small barbs’ Barbus humilis and B. trispilopleura of Lake Tana (Ethiopia): are they ecotypes of the same species?Environmental Biology of Fishes65373386doi:10.1023/A:1021110721565

Dejen E.Vijverberg J.Nagelkerke L. A. J.Sibbing F. A.2004Temporal and spatial distribution of microcrustacean zooplankton in relation to turbidity and other environmental factors in a large tropical lake (L. Tana, Ethiopia).Hydrobiologia5133949doi:10.1023/B:HYDR.0000018163.60503.B8

Dejen E.Vijverberg Graaf M.Sibbing F. A.2006Predicting and testing resource partitioning in a tropical fish assemblage of zooplanktivorous barbs: an ecomorphological approach.Journal of Fish Biology6913561378doi:10.1111/J.1095-8649.2006.01197.X

Eccles D. H., and Trewavas E. (1989). ‘Malawian cichlid fishes. The classification of some Haplochromine genera.’ (Lake Fish Movies: Herten: Germany.)

Echelle A. A., and Kornfield I. (1984). ‘Evolution of fish species flocks.’ (University of Maine at Orono Press: Orono, ME.)

Fowler J., Cohen L., and Jarvis P. (1998). ‘Practical Statistics for Field Biology.’ 2nd edn. (John Wiley and Sons: Chichester, UK.)

Galis F.Metz J. A. J.1998Why are there so many cichlid species?Trends in Ecology & Evolution1312doi:10.1016/S0169-5347(97)01239-1

Genner M. J.Turner G. F.Hawkins S. J.1999Foraging of rocky habitat cichlid fishes in Lake Malawi: coexistence through niche partitioning?Oecologia121283292

Getahun A. (2000). Systematic studies of the African species of the genus Garra (Pisces: Cyprinidae). Ph.D. Thesis, City University of New York, New York.

Johnson T. C.Scholz C. A.Talbot M. R.Kelts K.Ricketts R. D.Ngobi al.1996Late Pleistocene desiccation of Lake Victoria and rapid evolution of cichlid fishes.Science27310911093doi:10.1126/SCIENCE.273.5278.1091Pubmed Abstract

Johnson T. C.Kelts K.Odada E.2000The holocene history of Lake Victoria.Ambio29211doi:10.1639/0044-7447(2000)029[0002:THHOLV]2.0.CO;2

Kornfield I., and Carpenter K. E. (1984). Cyprinids of Lake Lanao, Philippines: taxonomic validity, evolutionary rates and speciation scenarios. In ‘Evolution of Fish Species Flocks’. (Eds A. A. Echelle and I. Kornfield.) pp. 69–83. (Orono Press: Orono, ME.)

Lamb H. F.Bates C. R.Coombes P. V.Marshall M. H.Umer M.Davies S. al.2007Late Pleistocene desiccation of Lake Tana, source of the Blue Nile.Quaternary Science Reviews26287299doi:10.1016/J.QUASCIREV.2006.11.020

Liem K.1973Evolutionary strategies and morphological innovations: cichlid pharyngeal jaws.Systematic Zoology22425441doi:10.2307/2412950

Liem K. F.1980Adaptive significance of intra- and interspecific differences in the feeding repetoires of cichlid fishes.American Zoologist201295314doi:10.1093/ICB/20.1.295

Losos J. B.Jackman T. R.Larson Queiroz K.Rodríguez-Schettino L.1998Contingency and determinism in replicated adaptive radiations of island lizards.Science27921152118doi:10.1126/SCIENCE.279.5359.2115Pubmed Abstract

Mina M. V.Mironovsky A. N.Dgebuadze Yu. Yu.1996Lake Tana large barbs: phenetics, growth and diversification.Journal of Fish Biology48383404doi:10.1111/J.1095-8649.1996.TB01435.X

Mittelbach G. G.Persson L.1998The ontogeny of piscivory and its ecological consequences.Canadian Journal of Fisheries and Aquatic Sciences5514541465doi:10.1139/CJFAS-55-6-1454

Nagelkerke L. A. J.Sibbing F. A.1996Reproductive segregation among the large barbs (Barbus intermedius complex) of Lake Tana, Ethiopia. An example of intralacustrine speciation?Journal of Fish Biology4912441266

Nagelkerke L. A. J.Sibbing F. A.1998The ‘Barbus’ intermedius species flock of Lake Tana (Ethiopia): I – The ecological and evolutionary significance of morphological diversity.The Italian Journal of Zoology65Suppl.37

Nagelkerke L. A. J.Sibbing F. A.2000The large barbs (Barbus spp., Cyprinidae, Teleostei) of Lake Tana (Ethiopia), with a description of a new species, Barbus osseensis.Netherlands Journal of Zoology50179214

Nagelkerke L. A. J.Sibbing F. A.Boogaart J. G. M.Lammens E. H. R. R.Osse J. W. M.1994The barbs (Barbus spp.) of Lake Tana: a forgotten species flock?Environmental Biology of Fishes39122doi:10.1007/BF00004751

Nagelkerke L. A. J.Mina M. V.Wudneh T.Sibbing F. A.Osse J. W. M.1995In Lake Tana, a unique fish fauna needs protection.Bioscience45772775doi:10.2307/1312629

Nagl S.Tichy H.Mayer W. E.Takezaki N.Takahata N.Klien J.2000The origin and age of haplochromine fishes in Lake Victoria, East Africa.Proceedings of the Royal Society of London. Series B. Biological Sciences26710491061doi:10.1098/RSPB.2000.1109

Nelson J. S. (1994) ‘Fishes of the World.’ (Wiley: New York.)

Palstra A. Graaf M.Sibbing F. A.2004Riverine spawning and reproductive segregation in a lacustrine species flock, facilitated by homing?Animal Biology544393415doi:10.1163/1570756042729519

Piet G. J.Pet J. S.Gurunge W. A. H. P.Vijverberg J.van Densen W. L. T.1999Resource partitioning along three niche dimensions in a size-structured tropical fish assemblage.Canadian Journal of Fisheries and Aquatic Sciences5612411254doi:10.1139/CJFAS-56-7-1241

Ribbink A. J.Marsh B. A.Marsh A. C.Sharp B. J.1983A preliminary survey of the cichlid fishes of rocky habitats in Lake Malawi.South African Journal of Zoology18149310

Ross S. T.1986Resource partitioning in fish assemblages: a review of field studies.Copeia1986352388

Rüber L.Verheyen E.Meyer A.1999Replicated evolution of trophic specializations in an endemic cichlid fish lineage from Lake Tanganyika.Proceedings of the National Academy of Sciences of the United States of America961023010235doi:10.1073/PNAS.96.18.10230Pubmed Abstract

Schliewen U.Tautz D.Pääbo S. P.1994Sympatric speciation suggested by monophyly of crater lake cichlids.Nature368629632doi:10.1038/368629A0Pubmed Abstract

Schliewen U.Rassman K.Markmann M.Markert J.Kochers T.Tautz D.2001Genetic and ecological divergence of a monophyletic cichlid species pair under fully sympatric conditions in Lake Ejagham, Cameroon.Molecular Ecology1014711488doi:10.1046/J.1365-294X.2001.01276.XPubmed Abstract

Schluter D. (2002). ‘The Ecology of Adaptive Radiation.’ (Oxford University Press: Oxford, UK.)

Schluter D.McPhail J. D.1993Character displacement and replicate adaptive radiation.Trends in Ecology & Evolution8197200doi:10.1016/0169-5347(93)90098-A

Seehausen O. (1996). ‘Lake Victoria Rock Cichlids.’ (Verduijn Cichlids: Germany.)

Seehausen O.van Alpen J. J. M.Witte F.1997Chichlid fish diversity threatened by eutrophication that curbs sexual selection.Science277533318081811doi:10.1126/SCIENCE.277.5333.1808

Sevenster J. G.Bouton N.1997The statistical significance of diets and other resource utilization patterns.Netherlands Journal of Zoology483267272doi:10.1163/156854298X00110

Sibbing F. A. (1991a). Food capture and oral processing. In ‘Cyprinid Fishes: Systematics, Biology and Exploitation’. (Eds J. J. Winfield and J. S.Nelson.) pp. 377–412. (Chapman and Hall: London.)

Sibbing F. A. (1991b). Food processing by mastication in cyprinid fish. In ‘Feeding and the Texture of Food’. (SEB Seminar series 44.) (Eds J. F. V. Vincent and P. J. Lillford.) pp. 57–92. (Cambridge University Press: Cambridge.)

Sibbing F. A.Nagelkerke L. A. J.2000Resource partitioning by Lake Tana barbs predicted from fish morphometrics and prey characteristics.Reviews in Fish Biology and Fisheries10393437doi:10.1023/A:1012270422092

Sibbing F. A.Osse J. W. M.Terlouw A.1986Food handling in carp (Cyprinus carpio L.): its movement patterns, mechanisms and limitations.Journal of Zoology210161203

Sibbing F. A.Nagelkerke L. A. J.Stet R. J. M.Osse J. W. M.1998Speciation of endemic Lake Tana barbs (Cyprinidae, Ethiopia) driven by trophic resource partitioning; a molecular and ecomorphological approach.Aquatic Ecology32217227

Snoeks J.2000How well known is the ichthyodiversity of the large East African lakes?Advances in Ecological Research311738

Snorrason S. S.Skúlason S.Sandlund O. T.Malmquist H. J.Jónsson B. J.Jonasson P. M.1989Shape polymorphism in arctic charr, Salvinus alpinus, in Thingvallavatn, Iceland.Physiology and Ecology Japan1393404

Streelman J. D.Danley P. D.2003The stages of vertebrate evolutionary radiation.Trends in Ecology & Evolution183126131

Sturmbauer C.1998Explosive speciation in cichlid fishes of the African Great Lakes, a dynamic model of adaptive radiation.Journal of Fish Biology53Suppl. A1836

van Oijen M. J. P.1982Ecological differentiation among the piscivorous haplochromine cichlids of Lake Victoria (East Africa).Netherlands Journal of Zoology323336363

Verheyen E.Salzburger W.Snoeks J.Meyer A.2003The origin of the superflock of cichlid fishes from Lake Victoria, East Africa.Science300325329doi:10.1126/SCIENCE.1080699Pubmed Abstract

Winemiller K. O.Kelso-Winemiller L. C.1994Comparative ecology of the African pike, Hepsetus odoe, and tigerfish, Hydrocynus forskahlii, in the Zambezi River floodplain.Journal of Fish Biology45211225doi:10.1111/J.1095-8649.1994.TB01301.X

Witte F.1980Initial results of the ecological survey of the haplochromine species from the Mwanza Gulf of Lake Victoria (Tanzania): breeding patterns, trophic and species distribution with recommendations for commercial trawl-fishery.Netherlands Journal of Zoology31175202doi:10.1163/002829680X00230

Witte F.van Oijen M. J. P.1990Taxonomy, ecology and fishery of Lake Victoria haplochromine trophic groups.Zoölogische Verhandelingen (Leiden)262147

Witte F., and van Oijen M. J. P. (1995). Biology of haplochromine trophic groups. In ‘Fish Stocks and Fisheries of Lake Victoria’. (Eds F. Witte and W. L. T. van Densen.) pp. 321–335. (Samara House: Cardigan, UK.)

Zworykin D. D.Budaev S. V.Darkov A. A.Dzerzhinskii K. F.Lyovin B. A.Mina M. V.2006Assessment of the role of chemoreception in the mate choice in barbs of the Barbus intermedius complex from Lake Tana, Ethiopia.Journal of Ichthyology468661667

Export Citation Cited By (25)