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Ignacio Doadrio - One of the best experts on this subject based on the ideXlab platform.
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consideraciones taxonomicas sobre Barbus moulouyensis pellegrin 1924 actinopterygii cyprinidae con la descripcion de una especie nueva de lucioBarbus heckel 1843 de marruecos
Graellsia, 2016Co-Authors: Ignacio Doadrio, Miriam Casallopez, Silvia PereaAbstract:The taxonomy of Barbus Cuvier and Cloquet, 1816 has been reviewed in the last years and as consequence some species traditionally included in genus Barbus sensu lato have been assigned to different genera. In North Africa the species of the former genus Barbus have been included in the genera LucioBarbus Heckel, 1843, CarasoBarbus Karaman, 1971 and Enteromius Cope, 1867. We studied populations of the former genus Barbus of the Moulouya river basin in Morocco through molecular, morphometric, and osteological data. Our data clearly showed that populations from Moulouya river basin described originally as Barbus moulouyensis Pellegrin, 1924 belong to the genus CarasoBarbus and not to LucioBarbus . Moreover, populations of the genus LucioBarbus exist in the Moulouya river basin and could not be assigned to any previously described species. Consequently, we describe a new LucioBarbus species from the Moulouya river basin.
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phylogenetic relationships of the algae scraping cyprinid genus capoeta teleostei cyprinidae
Molecular Phylogenetics and Evolution, 2012Co-Authors: B A Levin, Silvia Perea, Jorg Freyhof, Zdeněk Lajbner, Asghar Abdoli, Muhammet Gaffaroglu, Mufit Ozulug, Haikaz R Rubenyan, Vladimir B Salnikov, Ignacio DoadrioAbstract:We reconstructed the matrilineal phylogeny of Asian algae-eating fishes of the genus Capoeta based on complete mitochondrial gene for cytochrome b sequences obtained from 20 species sampled from the majority of the range and 44 species of closely related barbs of the genera Barbus s. str. and LucioBarbus. The results of this study show that Capoeta forms a strongly supported monophyletic subclade nested within the LucioBarbus clade, suggesting that specialized scraping morphology appeared once in the evolutionary history of the genus. We detected three main groups of Capoeta: the Mesopotamian group, which includes three species from the Tigris–Euphrates system and adjacent water bodies, the Anatolian–Iranian group, which has the most diversified structure and encompasses many species distributed throughout Anatolian and Iranian inland waters, and the Aralo-Caspian group, which consists of species distributed in basins of the Caspian and Aral Seas, including many dead-end rivers in Central Asia and Northern Iran. The most probable origination pathway of the genus Capoeta is hypothesized to occur as a result of allopolyploidization. The origin of Capoeta was found around the Langhian–Serravallian boundary according to our molecular clock. The diversification within the genus occurred along Middle Miocene–Late Pliocene periods.
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haplotype diversity and phylogenetic relationships among the iberian barbels Barbus cyprinidae reveal two evolutionary lineages
Journal of Heredity, 2002Co-Authors: Ignacio Doadrio, Jose A Carmona, Annie MachordomAbstract:The phylogenetic relationships and haplotype diversity of all Iberian barbels were examined by analyzing the complete mitochondrial cytochrome b gene sequence (1141 bp) of 72 specimens from 59 Iberian localities. Phylogenetic findings demonstrated a clear distinction between two mitochondrial lineages and confirmed the existence of two previously considered subgenera: Barbus and LucioBarbus. The first subgenus, Barbus, is represented on the Iberian Peninsula by Barbus haasi and Barbus meridionalis. The second subgenus, LucioBarbus, includes the remaining endemic Iberian species: Barbus comizo, Barbus bocagei, Barbus microcephalus, Barbus sclateri, Barbus guiraonis, and Barbus graellsii. Mean haplotype divergence between these subgenera was 10.40%, providing evidence of a clear subdivision within the Iberian barbels. Our results conflict with those reported in a recent study, based on 307 cytochrome b base pairs, that failed to identify any division within the genus Barbus in the Iberian Peninsula. The inclusion of nine further species belonging to this genus (used as outgroups) allowed us to establish a closer relationship of the Iberian species of the subgenus Barbus with other European taxa than with the Iberian LucioBarbus, which was found to cluster with North African, Caucasian, and Greek species. At the population level, no biogeographic structure was shown by specimens of each species (only 5.98% of the variation was attributable to differences among populations of each species). Given the discrete amount of divergence found among the LucioBarbus species, the formation of current hydrographic basins during the Plio-Pleistocene seems to have played a major role in their isolation and evolution.
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evolutionary history and speciation modes in the cyprinid genus Barbus
Proceedings of The Royal Society B: Biological Sciences, 2001Co-Authors: Annie Machordom, Ignacio DoadrioAbstract:Phylogenetic relationships and evolutionary patterns in the genus Barbus were examined through the analysis of the complete sequences of three mitochondrial genes: ATPases 8 and 6, which overlap slightly, and cytochrome b. This complex genus includes diploid as well as tetraploid and hexaploid species that are distributed throughout the Palaearctic, Ethiopian and Asiatic biogeographical regions. Given that genome duplication is an important evolutionary mechanism in eukaryotes, in the present report we attempt to describe its role in the evolution of the genus Barbus, as well as drawing systematic and phylogenetic conclusions. The phylogenetic results indicated the splitting of the current Barbus genus into five main mitochondrial lineages corresponding to (i) the genus Barbus sensu stricto (tetraploid, which is subdivided into the subgenera Barbus and LucioBarbus), (ii) the hexaploid species, (iii) the Ethiopian tetraploid species, (iv) the African diploid species, and (v) the Asian diploid species. The branching of 'foreign' genera as sister groups of some of these monophyletic assemblages (such as Aulopyge is to Barbus sensu stricto or Varicorhinus is to the hexaploid barbels) demonstrates the polyphyly of the group. Moreover, the relationships between the proposed lineages also show that genome duplication may be considered as a homoplasic character since it must have occurred over at least three independent periods and/or in three independent areas. In relation to the possible saltational evolutionary model for the polyploid species examined here, it was found that, although feasible at the nuclear level, the mitochondrial markers looked at do not appear to have undergone this type of evolution. Rather, they seem to have experienced more or less constant change through time.
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new evidence of hexaploidy in large african Barbus with some considerations on the origin of hexaploidy
Journal of Fish Biology, 1995Co-Authors: Jeanfrancois Guegan, Petr Rab, Annie Machordom, Ignacio DoadrioAbstract:Three species of‘ large’ African Barbus from the Republic of Guinea (West Africa), were characterized by the chromosome numbers (2N) of 148 (B. bynni occidentalis and B. wurtzi) and 150 (B. petitjeani Daget, 1962). All these species have a karyotype which corresponds to the evolutionary hexaploid level. The karyotype of B. petitjeani is composed of chromosomes clearly grouped into morphologically homomorphic sextets which may document the origin of hexaploidy via an autopolyploidic event. Present findings extend the known distribution of evolutionary hexaploidy in‘ large‘ African Barbus to West Africa and show evidence of the pan-African distribution of this phenomenon.
Massimo Lorenzoni - One of the best experts on this subject based on the ideXlab platform.
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Genetic and phenotypic displacement of an endemic Barbus complex by invasive European barbel Barbus Barbus in central Italy
Biological Invasions, 2020Co-Authors: Serena Zaccara, J R Britton, Antonella Carosi, Silvia Quadroni, Vanessa Santis, Isabella Vanetti, Giuseppe Crosa, Massimo LorenzoniAbstract:Invasions of alien fishes can result in considerable consequences for native biodiversity, including local extinctions of native species through genetic introgression. In Italy, the alien European barbel Barbus Barbus was first detected in 1994. It has since undergone range expansion, raising conservation concerns on their impacts on endemic Barbus species, including Barbus plebejus and Barbus tyberinus . Here, the genetic and phenotypic consequences of B. Barbus invasion in the Tyrrhenian and Adriatic basins of central Italy were assessed by comparing ‘invaded’ with ‘uninvaded’ river sections that remain free of B. Barbus due to barriers preventing their upstream dispersal. In both basins, uninvaded sites were confirmed as B. Barbus free, but the endemic populations had low genetic variability. In the invaded sections, haplotype and nucleotide diversity was relatively high, with introgression skewed towards B. Barbus genes, with the barbel populations comprising of only 4% and 23% of pure B. tyberinus and B. plebejus respectively. Relatively high morphological differentiation was apparent between pure B. tyberinus and hybrid forms, whilst differences were less apparent between pure B. plebejus and their hybrid forms. Thus, the endemic Barbus species only persist in areas that remain free of invasive B. Barbus , with this only due to river structures that impede their upstream movements. As these structures also limit the effective population size of the endemic species, conservation plans must reconcile B. Barbus dispersal prevention with the need to increase the population connectivity of the endemics.
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morphologic and genetic variability in the Barbus fishes teleostei cyprinidae of central italy
Zoologica Scripta, 2019Co-Authors: Serena Zaccara, Antonella Carosi, Robert Britton, Silvia Quadroni, Isabella Vanetti, Giuseppe Crosa, Gianandrea La Porta, Massimo LorenzoniAbstract:© 2019 Royal Swedish Academy of Sciences Italian freshwaters are highly biodiverse, with species present including the native fishes Barbus plebejus and Barbus tyberinus that are threatened by habitat alteration, fish stocking and invasive fishes, especially European barbel Barbus Barbus. In central Italy, native fluvio-lacustrine barbels are mainly allopatric and so provide an excellent natural system to evaluate the permeability of the Apennine Mountains. Here, the morphologic and genetic distinctiveness was determined for 611 Barbus fishes collected along the Padany–Venetian (Adriatic basins; PV) and Tuscany–Latium (Tyrrhenian basins; TL) districts. Analyses of morphological traits and mitochondrial DNA sequence data explored the natural and anthropogenic factors that have shaped their distribution ranges. Over 100 alien B. Barbus were recorded in the Tiber basin (TL district) and Metauro basin (PV district). Comparisons of genetic and morphometric data revealed that morphometric data could identify alien B. Barbus from native Barbus, but could not differentiate between B. tyberinus and B. plebejus. Genetic analyses revealed ~50 D-loop mtDNA haplotypes and identified a distinct Barbus lineage present only in the Vomano River at the southern boundary of PV district. Demographic expansion and molecular variance analyses revealed a lack of geographic structuring across the sampling regions. While the contemporary B. plebejus distribution has been driven primarily by anthropogenic fish translocations, the dispersal of B. tyberinus has been via natural dispersion, including their crossing of the Apennine Mountains via temporary river connectivity. The results also revealed that the Barbus fishes of the mid-Adriatic region of Europe have a complex pattern of local endemism. To conserve these patterns of genetic uniqueness, especially in the mid-Adriatic basins, Barbus fishes should be managed by treating them as unique evolutionary units and ceasing translocations of all Barbus fishes between river basins.
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ecological effects of the european barbel Barbus Barbus l 1758 cyprinidae invasion on native barbel populations in the tiber river basin italy
The European Zoological Journal, 2017Co-Authors: Antonella Carosi, L Ghetti, G La Porta, Massimo LorenzoniAbstract:AbstractThe purpose of this study was to investigate the effects of the European barbel Barbus Barbus (L., 1758) invasion in the Tiber River basin (Italy) on the native Tiber barbel Barbus tyberinus Bonaparte, 1839, verifying whether the co-occurrence played a negative impact on growth rate and relative weight. Fish census data were collected during three periods (2000–2005, 2006–2010, 2011–2015) at 158 sampling sites. Since its first record in 1998, European barbel rapidly spread in the study area: it was present in more than 20% of the monitoring sites, where it is leading to the gradual replacement of Tiber barbel by widening its distribution in the Tiber River and in the downstream reaches of the main tributaries. By contrast, Tiber barbel has suffered from this competition, as demonstrated by the fact that the mean value of the relative weight was significantly higher where European barbel was absent. The results obtained suggested that this non-native species could be a serious threat to the conserv...
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Ecological effects of the European barbel Barbus Barbus (L., 1758) (Cyprinidae) invasion on native barbel populations in the Tiber River basin (Italy)
'Informa UK Limited', 2017Co-Authors: Antonella Carosi, L Ghetti, G La Porta, Massimo LorenzoniAbstract:The purpose of this study was to investigate the effects of the European barbel Barbus Barbus (L., 1758) invasion in the Tiber River basin (Italy) on the native Tiber barbel Barbus tyberinus Bonaparte, 1839, verifying whether the co-occurrence played a negative impact on growth rate and relative weight. Fish census data were collected during three periods (2000–2005, 2006–2010, 2011–2015) at 158 sampling sites. Since its first record in 1998, European barbel rapidly spread in the study area: it was present in more than 20% of the monitoring sites, where it is leading to the gradual replacement of Tiber barbel by widening its distribution in the Tiber River and in the downstream reaches of the main tributaries. By contrast, Tiber barbel has suffered from this competition, as demonstrated by the fact that the mean value of the relative weight was significantly higher where European barbel was absent. The results obtained suggested that this non-native species could be a serious threat to the conservation status of endemic Tiber barbel, and constitute the premise to underpin conservation strategies aiming to preserve native freshwater biodiversity
Patrick Berrebi - One of the best experts on this subject based on the ideXlab platform.
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Rare and asymmetrical hybridization of the endemic Barbus carpathicus with its widespread congener Barbus Barbus
Journal of Fish Biology, 2009Co-Authors: Z. Lajbner, Patrick Berrebi, V. Slechtova, V. Slechta, M. Svatora, Petr KotlíkAbstract:In endemic species that co-occur with widespread congeners, hybridization can lead to an influx of novel and beneficial genetic variation, but high rates of introgression may cause genetic swamping of the endemic species and have detrimental effects on its survival potential. This study examines hybridization between sympatric populations of the Carpathian barbel Barbus carpathicus, a recently discovered cryptic species with a restricted range, and the widespread common barbel Barbus Barbus. Based on six diagnostic allozyme loci, a microsatellite locus and mtDNA, hybrids were found to be present at multiple localities within the Vistula River drainage (Baltic Sea) as well as in the Tisza River system of the Danube River drainage (Black Sea). However, the numbers of hybrids were very low; four individuals of 230 fish sampled from the Vistula drainage. Bayesian assessment of their nuclear genotypes suggested that two hybrids in the Vistula drainage and nine in the Tisza system were F-1 generation, and one in the Vistula drainage and one in the Tisza system were backcrosses (BC) to B. Barbus, while no F-2 or BC to B. carpathicus were detected. No hybrid carried B. carpathicus mtDNA and cytonuclear linkage disequilibria showed significant positive associations between hybrid genotypes and B. Barbus mtDNA, suggesting unidirectionality in the interspecific mating with a disproportionate contribution of B. Barbus mothers. Despite geographically broad occurrence of hybrids, these data provide evidence of strong constraints on hybridization in the native breeding habitats and the lack of introgression towards B. carpathicus.
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Genetic subdivision and biogeography of the Danubian rheophilic barb Barbus petenyi inferred from phylogenetic analysis of mitochondrial DNA variation.
Molecular Phylogenetics and Evolution, 2002Co-Authors: Petr Kotlík, Patrick BerrebiAbstract:Abstract The barb Barbus petenyi is a cyprinid widely distributed throughout the mountain regions in the Danube River basin. Phylogenetic analysis of the DNA sequence variation at the mitochondrial cytochrome b gene over much of this range yielded three deep-branching (5.9–9.4% average divergence), well-supported haplotype clades with mutually exclusive geographic distributions and divergence times estimated to be in the Tertiary. The clades did not form an altogether monophyletic group as the most divergent one coalesced more recently with haplotypes of phylogenetically close species than with the other B. petenyi haplotypes. This pattern was supported by bootstrap and log-likelihood Shimodaira–Hasegawa tests. The other two were sister clades, but their distinctiveness was supported by previous allozyme data. Hence, from a taxonomic point of view, the current recognition of B. petenyi is erroneous, as it does not represent a single evolutionary lineage, and we suggest that three species be recognized instead. Substantial phylogeographic differences were evident among the three putative species, the two more southerly ones displaying significant structure, which suggested that they each survived in several glacial refugia throughout the Pleistocene. The phylogeographic pattern of multiple populations of rheophilic barbs with a history of long-term persistence and separation within the Danube River basin is novel within fishes and provides a hypothesis against which phylogeographic patterns among other similarly distributed rheophilic species may be compared.
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biogeography and pattern of gene flow among Barbus species teleostei cyprinidae inhabiting the italian peninsula and neighbouring adriatic drainages as revealed by allozyme and mitochondrial sequence data
Biological Journal of The Linnean Society, 2002Co-Authors: Costas S. Tsigenopoulos, Petr Kotlík, Patrick BerrebiAbstract:Genetic relationships among 24 Italian and Adriatic populations of barbs (genus Barbus) were assessed using electrophoretic analysis of allozymes and mitochondrial DNA sequences of the cytochrome b gene. Results obtained with both markers were concordant, but they were not congruent with the current morphology-based systematics and taxonomy. Populations assigned to the same nominal taxa (B. caninus, B. petenyi and B. rebeli), were very divergent in both allozymes and mtDNA, indicating that these populations deserve recognition as different units for conservation and management. On the other hand, the two fluvio-lacustrine taxa considered as distinct species (i.e. B. plebejus and B. tyberinus) are genetically very close to each other, showing no clear differences at either allozymes or mtDNA. The population of B. caninus from Pellice River carried allozyme alleles and mtDNA specific for B. plebejus, indicating a genetic introgression towards the former species. © 2002 The Linnean Society of London, Biological Journal of the Linnean Society, 2002, 75, 83–99.
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Molecular phylogeny of north mediterranean freshwater barbs (genus Barbus: cyprinidae) inferred from cytochrome b sequences: biogeographic and systematic implications.
Molecular Phylogenetics and Evolution, 2000Co-Authors: Costas S. Tsigenopoulos, Patrick BerrebiAbstract:We investigated phylogenetic relationships among north Mediterranean species of the genus Barbus using sequences of the cytochrome b gene. Our results indicate that the species belong to two major clades that are consistent with those previously defined from morphological features. The first clade includes species ranging from France to the Black Sea. In this clade, there is a well-supported monophyletic group of large-sized fluvio-lacustrine barbs; however, the monophyly of the small-sized rheophilic species is not clear. The second clade comprises species found in Spain, Greece, and Asia Minor and probably represents the oldest group present in the north Mediterranean rivers. In general, there is good concordance between geography and phylogenetic relationships. These results are compared to those from previous morphological- and allozyme-based studies and demonstrate widespread discordance and polyphyly in the traditional taxonomy of the genus Barbus. This study is one of the first reporting the phylogenetic and biogeographic relationships of a genus that is widely distributed in European rivers and contains species that are a major component of the European ichthyofauna.
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speciation of the genus Barbus in the north mediterranean basin recent advances from biochemical genetics
Biological Conservation, 1995Co-Authors: Patrick BerrebiAbstract:Abstract On the basis of population genetic studies, this article proposes a systematic and evolutionary redefinition of some of the Barbus species occurring in the north Mediterranean basin. The comparative value of enzymatic and nucleic acid markers is discussed. The various evolutionary branches of the genus Barbus reflect the main migrations of the freshwater fish fauna. The phylogeny thus allows the origin of the species to be reconstituted. Species occurring in the north of the Mediterranean basin are positioned along an intercontinental gradient frequently having different levels of ploidy: these include diploid species, tetraploid species belong to the subgenus Barbus and the hexaploid species of the subgenus LabeoBarbus . An integrated study of genetics, karyology, palaeontology, morphology and parasitology is suggested as the means of assessing the value of various evolutionary hypotheses proposed in the literature.
Silvia Perea - One of the best experts on this subject based on the ideXlab platform.
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consideraciones taxonomicas sobre Barbus moulouyensis pellegrin 1924 actinopterygii cyprinidae con la descripcion de una especie nueva de lucioBarbus heckel 1843 de marruecos
Graellsia, 2016Co-Authors: Ignacio Doadrio, Miriam Casallopez, Silvia PereaAbstract:The taxonomy of Barbus Cuvier and Cloquet, 1816 has been reviewed in the last years and as consequence some species traditionally included in genus Barbus sensu lato have been assigned to different genera. In North Africa the species of the former genus Barbus have been included in the genera LucioBarbus Heckel, 1843, CarasoBarbus Karaman, 1971 and Enteromius Cope, 1867. We studied populations of the former genus Barbus of the Moulouya river basin in Morocco through molecular, morphometric, and osteological data. Our data clearly showed that populations from Moulouya river basin described originally as Barbus moulouyensis Pellegrin, 1924 belong to the genus CarasoBarbus and not to LucioBarbus . Moreover, populations of the genus LucioBarbus exist in the Moulouya river basin and could not be assigned to any previously described species. Consequently, we describe a new LucioBarbus species from the Moulouya river basin.
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phylogenetic relationships of the algae scraping cyprinid genus capoeta teleostei cyprinidae
Molecular Phylogenetics and Evolution, 2012Co-Authors: B A Levin, Silvia Perea, Jorg Freyhof, Zdeněk Lajbner, Asghar Abdoli, Muhammet Gaffaroglu, Mufit Ozulug, Haikaz R Rubenyan, Vladimir B Salnikov, Ignacio DoadrioAbstract:We reconstructed the matrilineal phylogeny of Asian algae-eating fishes of the genus Capoeta based on complete mitochondrial gene for cytochrome b sequences obtained from 20 species sampled from the majority of the range and 44 species of closely related barbs of the genera Barbus s. str. and LucioBarbus. The results of this study show that Capoeta forms a strongly supported monophyletic subclade nested within the LucioBarbus clade, suggesting that specialized scraping morphology appeared once in the evolutionary history of the genus. We detected three main groups of Capoeta: the Mesopotamian group, which includes three species from the Tigris–Euphrates system and adjacent water bodies, the Anatolian–Iranian group, which has the most diversified structure and encompasses many species distributed throughout Anatolian and Iranian inland waters, and the Aralo-Caspian group, which consists of species distributed in basins of the Caspian and Aral Seas, including many dead-end rivers in Central Asia and Northern Iran. The most probable origination pathway of the genus Capoeta is hypothesized to occur as a result of allopolyploidization. The origin of Capoeta was found around the Langhian–Serravallian boundary according to our molecular clock. The diversification within the genus occurred along Middle Miocene–Late Pliocene periods.
Ferdinand A. Sibbing - One of the best experts on this subject based on the ideXlab platform.
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declining stocks of lake tana s endemic Barbus species flock pisces cyprinidae natural variation or human impact
Biological Conservation, 2004Co-Authors: Martin De Graaf, Marcel A M Machiels, T Wudneh, Ferdinand A. SibbingAbstract:The only remaining species flock of endemic, large cyprinid fishes is found in Lake Tana, Ethiopia. A monthly experimental trawl program was conducted in 1991-1993 and 1999-2001, sampling 12 stations distributed over three habitats differing in depth and distance to shore. The aim was to compare the total abundance, spatial distribution and proportion of juveniles of the most common Barbus species in the Bahar Dar Gulf between both periods. We found a sharp reduction (75%) in total abundance, both in number and biomass of the Barbus species and even more (90%) in the number of juveniles between the two periods. However, the spatial distribution of the different Barbus species over the three habitats had not changed. High natural variability in fish stocks might be expected in environmentally unstable lakes. Although strongly pulsed (seasonal), Lake Tana is a relatively stable system. No major differences were found in abiotic parameters in 1990s that could have caused the dramatic changes in abundance. The most likely explanation is the negative impact of the motorised, commercial gillnet fishery targeting the spawning aggregations of these barbs. The drastic decline in juveniles points especially towards serious recruitment over-fishing. The results stress the need for the immediate development of a sound management plan focussing on fishing effort restrictions during the Bat-bus breeding season. (C) 2003 Elsevier Ltd. All rights reserved.
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Toothless predators: feeding performance and techniques among the piscivores within Lake Tana's endemic Barbus species flock (Pisces:Cyprinidae)
Journal of Fish Biology, 2003Co-Authors: M. De Graaf, Ferdinand A. Sibbing, Jan W. M. OsseAbstract:With more than 2000 fish species the Cyprinidae is the largest family of vertebrates. Lake Tana, a large lake (3050 km2) situated in the NW- highlands of Ethiopia, harbours, as far as we know the only remaining intact species flock of large (max. 100 cm FL) cyprinid fishes (15 Barbus spp.). One of the most intriguing aspects of this endemic Barbus species flock is the large number of piscivores (8). Cyprinid fishes seem not well designed for piscivory, they lack teeth in the oral jaw, have a small slit-shaped pharyngeal cavity and all lack a stomach with low pH for digesting large prey. Many barbs are benthivorous species, like the ancestral barb in Lake Tana's isolated system. Why then is piscivory, which is rare among cyprinids, so common in Lake Tana Barbus? The aim of present study was to compare the performance and techniques of these piscivorous Barbus with known piscivores from other fish families. We studied prey handling times over prey size, prey capture using high-speed movies, and assessed the effect of prey size on performance and prey selection in the field. Performances were explained by functional morphology of their feeding system. Overall, Lake Tana's piscivorous Barbus perform relatively ‘poor’, compared to piscivores from other fish families. For example, Lake Tana's piscivores are only able to handle prey fish smaller than 16% of their own body length. However, Lake Tana lacks potential piscivorous competitors, rendering the piscivorous Barbus by far the ‘best’ and apparently highly successful. They have adapted to all available macro-habitats (littoral, offshore pelagic and offshore benthic), using different techniques (ambush, pursuit and cruising), a unique scenario for barbs.
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The barbs (Barbus spp.) of Lake Tana: a forgotten species flock?
Environmental Biology of Fishes, 1994Co-Authors: Leopold A. J. Nagelkerke, Jos G. M. Boogaart, Ferdinand A. Sibbing, Eddy H R R Lammens, Jan W. M. OsseAbstract:In October–December 1990, the large barbs ( Barbus ) that contribute more than 35% of the catch in lake Tana (northern Ethiopia) were studied. Previous authors (Rüppell 1837, Boulenger 1902,1911, Bini 1940) described from 6 to 23 (sub)species for the lake. Banister (1973) lumped all of these into one subspecies: Barbus intermedius intermedius Rüppell,1837. We found that the Lake Tana Barbus could be readily categorized in at least 13 discrete morphotypes, some of which were already distinguished by local fishermen. None of the known descriptions are adequate to distinguish the barbs unambiguously, which is important for monitoring and management of developing fisheries. Intermediates between morphotypes were rare (< 10%). By applying canonical discriminant analysis on a set of 17 morphometric characters (including some directly associated with feeding) our initial morphotype-distinction was confirmed. Also, differences between the morphotypes in distribution, related to depth and substratum were found, as well as differences in intestinal contents, a key to the food-niche. The high number of piscivorous morphotypes (8 out of 13) was striking as piscivory is relatively rare among cyprinids. Piscivory was found to be highly correlated with morphological (feeding related) characters. The presence of discrete morphotypes, that also differ in food-niche and distribution, strongly suggests that several distinct populations exist, that may be (partly or completely) reproductively segregated. Knowledge about these populations, that may represent separate units of fish stock, is of crucial importance for the management of sustainable fisheries and protection of the biodiversity in Lake Tana. It is possible that several species or even a unique cyprinid species flock are present, that urgently need protection.