Barbus Species Research Articles

Karyotypes of three «small»Barbusspecies (Cyprinidae) from Republic of Guinea (Western Africa) with a review on karyology of African smallBarbus

SUMMARYKaryotypes of three barbels belonging to the group of «small» African species of Barbus sensu lato, B. bigornei, B. ablabes and B. macrops from the Republic of Guinea (Western Africa), were investigated. Diploid chromosome (2n) and chromosome arm (NF) numbers were for B. bigornei 2n = 48 and NF = 96, for B. ablabes 2n= 50 and NF = 98, and for B. macrops 2n = 50 and NF = 92, respectively. The first pair of metacentric chromosomes in all karyotypes was remarkably larger, and it can be considered as a «marker» element for these 3 species. The karyotype characteristics of Barbus species under study demonstrate that they belong to the diploid group of African barbels and they are, in fact, not related to the genus Barbus sensu stricto which is of a distinct evolutionary polyploid origin. Karyology of this poorly studied African cyprinid group is reviewed and discussed.

Isozyme and allozyme differences in four shortfin barb ( Barbus brevipinnis Jubb, 1966) populations with reference to an undescribed species from the Transvaal, South Africa

Starch gel-electrophoresis was used to survey genetic variation among samples from four different populations of Barbus brevipinnis. Thirteen of 30 loci were found to be polymorphic. It is suggested, based on the extent of the genetic differences between populations, that the populations collected from the Waterberg should be regarded as an undescribed species of Barbus.

Ecomorphology as a tool in fisheries: identification and ecotyping of Lake Tana barbs (Barbus intermedius complex), Ethiopia

Fisheries development of Lake Tana, Ethiopia, urgently requires the identification of its unknown units of fish stock. A diversity of large barbs (up to 80 cm SL), lumped into one species Barbus intermedius and contributing over 35% of the annual catch, consists of at least thirteen distinct morphotypes (Nagelkerke et al., 1994), possibly species. Their abilities and limitations in food selection and feeding can be predicted from structural specializations following functional morphological methods. Using ecomorphology, a spectrum of ecotypes ranging from detritivores to piscivores is predicted. Such hypotheses may be tested by analysing these fishes' intestinal contents. From knowledge of available food organisms and the trophic segregation thus found among barbs and sympatric species, a preliminary food web has been constructed. This food web, together with quantitative studies on population dynamics and energy flow, provides a biological framework for rational fisheries management aiming at sustainable production and protection of biodiversity.

Dry-season spawning in a cyprinid fish of southern India

A population of the S. Indian cyprinid fishBarbus melanampyx was sampled monthly through 24 months. Seasonal cycles of the gonado-somatic index (GSI), ovarian stages, male breeding tubercles, spawning behaviour and population structure were assessed. These fish breed strictly seasonally during the main dry period: December/January through April. Comparison with other Barbus species of the same general region led to the conclusion that the patterns of reproductive investment ofB. melanampyx are similar to those of perennial species, and different from those of wet-season spawners. The reasons for this rather unexpected result were found in the more constant conditions prevailing during a dry season as compared to the monsoon. It was argued thatB. melanampyx and the species spawning perennially are in effect ‘small-brood’ spawners, rather than partial spawners.

Morphological Divergence During Growth in the Large Barbs (Barbus Spp.) of Lake Tana, Ethiopia

Recently the large Lake Tana barbs (genus Barbus) were categorized into at least 13 distinct morphotypes based on large differences in general morphology, distribution and feeding habits. They are probably different populations and may even constitute a unique cyprinid species flock. This study demonstrates that 11 of the 14 morphotypes (as an additional morphotype 'Shorthead' is identified in this paper) can already be distinguished by their general external features at fork lengths of less than 12 cm. These distinctions were verified by statistical analysis of morphometric data. The distinction of the morphotypes in small specimens supports the hypothesis that several distinct Barbus species exist in Lake Tana. Knowledge of the population structure and species composition is very important for the reconstruction of the evolutionary history and mechanisms of this unique fish community. Moreover, in order to protect the biodiversity of the lake, it is important that the fisheries in the lake only increase on a sustainable basis and a detailed knowledge of the fish community structure is vital to achieve this goal.

Karyological study of some cyprinid species from Ethiopia. The ploidy differences between large and small Barbus of Africa

Chromosome sets of nine species of Barbus and a species of Varicorhinus from Ethiopia were investigated. All large Barbus (B. bynni, B. intermedius, B. ethiopicus) and V. beso are shown to have 2N =150, whereas all small Barbus (B. anema, B. kerstenii, B. paludinosus, and three unidentified (probably undescribed) species have 2N = 50. Based on the karyological data and on the published morphological data, an independent origin of small and large Barbus of Africa is suggested. The authors believe that large Barbus of Africa constitute a monophyletic group and that this group has no sister‐group relationships with any of the small Barbus of Africa.

Karyological study of some cyprinid species from Ethiopia. The ploidy differences between large and small Barbus of Africa

Chromosome sets of nine species of Barbus and a species of Varicorhinus from Ethiopia were investigated. All large Barbus (B. bynni, B. intermedius, B. ethiopicus) and V. beso are shown to have 2N =150, whereas all small Barbus (B. anema, B. kerstenii, B. paludinosus, and three unidentified (probably undescribed) species have 2N = 50. Based on the karyological data and on the published morphological data, an independent origin of small and large Barbus of Africa is suggested. The authors believe that large Barbus of Africa constitute a monophyletic group and that this group has no sister-group relationships with any of the small Barbus of Africa.

Comparative performances of non-visual food search in the hypogean cyprinidPhreatichthys andruzziiand in the epigean relativeBarbus filamentosus

The anophthalmic hypogean cyprinid Phreatichthys andruzzii Vinciguerra shows a more efficient food searching behaviour than blinded specimens of the epigean species Barbus filamentosus Cuvier and Valenciennes. This difference seems to be related to a tendency to swim near the bottom of the aquarium and the behavioural stereotypes in food localization and intake. Both in P. andruzzii and in the blinded B. filamentosus food search is guided by chemical stimulation. Other data indicate that mechanical stimulation could play an important role in the feeding behaviour of the hypogean form. The behavioural analogies in food localization between P. andruzzii and the cave forms of the characid Astyanax fasciatus Cuvier are briefly discussed.

In situ pollution induced cytochrome P450 activity of freshwater fish: barbel ( Barbus barbus), chub ( Leuciscus cephalus) and nase ( Chondrostoma nasus)

The induction of cytochrome P450IA1 was detected in freshwater fish liver using 7-ethoxyresorufin- O-deethylase activity (EROD). Investigations took place in the river Durance in the south-east of France and revealed a strong induction downstream a chemical plant. This induction differed between the three species studied. The species Barbus barbus was more sensitive to the pollution. This might be due to the benthic feeding behaviour ofthat fish. The induction increased from February to October which was probably a concentration effect caused by the drastic drought that occurred in France in 1989.

Twelve new species of dactylogyrids (Platyhelminthes, Monogenea) from West African barbels (Teleostei, Cyprinidae), with some biogeographical implications

Fifteen species of dactylogyrid monogeneans, belong to Dactylogyrus and Dogielius were observed in seven different African species of Barbus and Varicorhinus (Teleostei, Cyprinidae). The barbels examined in West Africa were: Barbus occidentalis Boulenger, 1911, known in the large Sahel-Sudan rivers and in Gabon: B. waldroni Nordman, 1935, B. petitjeani Daget, 1962, B. sacratus Daget, 1963, B. parawaldroni Leveque, Thys van den Audenaerde & Traore, 1987 and Varicorhinus wurtzi (Pellegrin, 1908) are distributed in various coastal rivers in the Gulf of Guinea. B. bynni (Forskal, 1775) the seventh species, is found in East Africa where it is known in the Nile Basin and the lakes connected with it. Three previously reported monogeneans were found: Dactylogyrus pseudanchoratus Price & Gery, 1968, was identified on all the host species studied; D. falcilocus Guegan, Lambert & Euzet, 1988, was found on V. wurtzi from Little Scarcies in Guinea; D. ruahae Paperna, 1973, was found on B. sacratus, B. parawaldroni and V. wurtzi in the rivers flowing from the Fouta Djalon mountains in Guinea to the Atlantic.

Two lineages, diploid and tetraploid, demonstrated in African speciesBarbus(Osteichthyes, Cyprinidae)

Enzymatic polymorphism was studied in nine enzyme systems of four species of large African Barbus (B. bynni occidentalis Boulenger, 1911; B. sacrutus Daget, 1963; B. petitjeani Daget 1962; and B. wurtzi Pellegrin, 1908), two species of small African Barbus (B. guineensis Pellegrin, 1913 and B. cadenati Daget, 1962), and two species of European Barbus (B. barbus Linnaeus, 1758 and B. meridionalis). Like European Barbus , the large African Barbus were found to express more than 20 enzymatic loci for these systems (21 to 23), whereas the small African Barbus only expressed 14. This result suggests that large African Barbus are tetraploid like European Barbus and that small African Barbus are diploid like the Asian species. The two groups of African Barbus do not appear to be phylogenetically closer to each other than they are to European Barbus. Consequently, tetraploidi- zation must have occurred long ago in large African Barbus , and may correspond to the same event responsible for the origin of the European species.

Cytotaxonomic Studies in Iberian Cyprinids. III. Karyology of Portuguese Populations ofBarbusCuvier, 1817, with Some Reconsiderations on The Karyological Evolution of Cyprinidae

SUMMARYThe five species of Barbus living in Portuguese freshwaters were cytogenetically analysed using the air-dried method. They all have 2n = 100 complements and gross similarities, suggesting an interesting taxonomic affinity and the occurrence of delicate and punctual chromosome rearrangements on the respective differentiation process. Besides, they share some pecularities with the congeneric taxa until now examined, particularly with the Centro-European species, B. barbus. Based on several aspects, namely on the primitive and speciose character of the genus, a new model for the karyological evolution of the Cyprinidae is proposed. This one considers the existence of two types of polyploidy: one primarily derived from a Cypriniformes ancestor, and the other secondarily achieved from «diploidizied» species (2n = 50). The later, certainly less represented, must be considered due to the inequivocal presence of impair ploidy levels on natural populations and seems to be indirectly obtained by the acquisition of unisexual modes of reproduction. As for the genus now analysed, its inclusion on the group of primary polyploids is proposed.

An evaluation of the success of invasive fish species of the Great Fish River

Summary There is a worldwide concern over the impact assessment and management of altered ecosystems. Increasingly, attention is being focussed on the role of invasive species in environmental degradation. A practical example of the use of theoretical concepts is presented with particular reference to the invasive species Barbus aeneus, Clarias gariepinus, Austroglanis sclateri and Labeo capensis of the Great Fish River, South Africa. The intrinsic species characteristics of age, growth and reproduction are presented. The status of the invasion by exotic species and the susceptibility of the environment are described. Zusammenfassung Eine Bewertung des Erfolges in den Great Fish River eingewanderter Fischarten Ein weltweites Interesse gilt dem Einfluß, der Bewertung und dem Management veränderter Ökosysteme. Zunehmend richtet sich die Aufmerksamkeit auf neu eingewanderte Arten und ihre Rolle bei der Umweltzerstörung. Ein praktisches Beispiel der Nutzung eines theoretischen Konzeptes mit besonderem Schwerpunkt auf die in den Great Fish River, Südafrika, eingewanderten Arten Barbus aeneus, Clarias gariepinus, Gephyroglanis sclateri und Labeo capensis wird vorgestellt. Alter, Wachstum und Fortpflanzung der Arten wurden untersucht. Der Umfang der Einwanderung exotischer Arten und die Sensibilität der Umwelt werden beschrieben. Résumé Evaluation du succès d'espèces envahissantes de poissons dans la Great Fish River Dans le monde entier on s'intéresse sà l'influence, sà la détermination et sà l'exploitation d'écosystèmes altérés. De plus en plus l'attention est tirée sur le rôle des espèces envahissantes dans la dégradation de l'environnement. Un exemple pratique de l'application de concepts théoriques est présenté tout particu-lièrement en ce qui concerne les espèces envahissantes Barbus aeneus, Clarias gariepinus, Gephyroglanis sclateri et Labeo capensis dans la Great Fish River, Afrique du Sud. Les caractéristiques intrinsèques des espèces (âge, croissance, reproduction) sont préséntees. Le degré d'invasion par des espèces exotiques et la sensibilité de l'environnement sont décrits.

Similar Behaviour and Colour Patterns in 3 Not Closely Related Barbus Species. Is Evolutionary Convergence a Likely Explanation?

AbstractThe main theoretical issue of this paper is the interpretation of the close similarity of the total behaviour and colour patterns of 3 not closely related Barbus species. The case for evolutionary convergence is easy if the total pattern of each species is interpreted as a collection of evolutionary adaptations to the species' natural habitat. The thorough similarity of the 3 species must then be ascribed to key similarities between their natural habitats. However, it is argued that another interpretation is possible, in which the diverse traits cohere causally and have been acted upon as one whole by natural selection. In the extreme case of this alternative interpretation, the case for convergence may still be won, but it is a Pyrrhic victory: convergence has lost much of its usual meaning. Apart from the above discussion, the reproductive behaviour and spawning colours of the 3 species are described and compared in some detail. Possible functional reasons for a relatively small difference as to the degree of sexual colour dimorphism are discussed in relation to eye sizes and visual discrimination.

Reproductive biology of six Barbus species indigenous to Sri Lanka

Six Barbus species were sampled monthly in two river systems of SW-Sri Lanka, over a 15 month period. Sex ratio, size at maturity, maximum and modal sizes, distribution of egg sizes in mature ovaries and individual fecundities were measured. Seasonal changes in size distributions, sex ratio, frequency of female gonadal stages and the gonado-somatic index (GSI) were analysed on the basis of the monthly samples. Seasonal cycles in reproductive activity were assessed, using mainly the two last-mentioned parameters and the appearance of young in the populations. It was found that three of the species (B. bimaculatus, B. cumingi, B. vittatus) tend to concentrate their reproductive activities in certain months of the year, roughly coinciding with the seasonal peaks of precipitation. The other three (B. nigrofasciatus, B. dorsalis, B. titteya) spread their reproductive efforts more evenly through the year. Sexual dimorphism with females bigger, relatively early maturation of males, high maximum GSI values, a distinct ‘final mode’ of large mature ova in the egg-diameter distribution, and a comparatively steep increase of fecundity with body weight or gonad weight were found to be more or less consistently associated with seasonal reproduction.

Age and growth of a colonizing minnow, Barbus anoplus, in a man-made lake in South Africa

Aspects of the life history of Barbus anoplus were studied in Lake le Roux, a turbid man-made lake on the Orange River, South Africa. This minnow underwent a population explosion and successfully colonized the shoreline of the newly-formed lake during the early phases of reservoir filling. Male and female B. anoplus reach sexual maturity in one year at about 40 mm fork length. They have a multiple spawning habit with the first spawning in November–January and the second in February–March. The growth of the two resulting cohorts is discussed. It is proposed that the offspring from the second spawning not only acts as a ‘back-up’ but is capable of prolonging the life of that year-class into an additional reproductive season. Most of the minnows die after their second summer, but more offspring from the second spawning, especially females, live into a third summer. Females attain a larger maximum size (73 mm FL) and age (3–4 years) than males (60 mm FL, 2–3 years). B. anoplus is small and short-lived with a high seasonal reproductive potential, which is in contrast to the larger Barbus species in the Orange River system. These life-history traits enable the species to colonize and successfully inhabit unstable environments and probably account for its widespread distribution.

FISH POPULATIONS IN THE MIDDLE AND LOWER ORANGE RIVER, WITH SPECIAL REFERENCE TO THE EFFECTS OF STREAM REGULATION

SUMMARY The results of two surveys, in March 1982 and September 1983, on the distribution and status of freshwater fish in the highly regulated section of the Orange River, from the P.K. Le Roux Dam wall to the mouth of the Orange River in the Republic of South Africa are presented. Collections are reported for the first time from the restricted diamondiferous areas in the extreme lower section of the Orange River. The known range of twelve freshwater fish species in the system has been extended as far down as 1,5 km from the mouth. Special attention is given to the Red Data Book species, Barbus hospes which occurs and breeds throughout the lower Orange River. It is suggested that stream regulation has probably been beneficial for this small, riverine Barbus species in contrast to B. paludinosus and B. trimaculatus which prefer quieter well vegetated habitats.

Lactate dehydrogenase tissue specificity and characterization in the teleost genus Barbus

1. 1. The tissue specific patterns of lactate dehydrogenase (LDH) for four species of Barbus are reported. 2. 2. While all tissues (eye, brain, heart, intestine, liver, ovary, skeletal muscle and stomach) show isozymes of A and B subunit composition, only liver extracts possess isozymes resulting from C subunit synthesis. 3. 3. The relative susceptibility of Barbus LDH isozymes to inactivation by urea is similar to the hierarchy of susceptibility observed for these isozymes in other teleosts. 4. 4. In vitro hybridization of liver isozymes suggests that the restriction on LDH subunit assembly in Barbus is the result of spatial and/or temporal isolation of subunit synthesis.

Habitat, Associations and Competition of Eight Barbus (= Puntius) Species (Pisces, Cyrinidae) Indigenous To Sri Lanka

A detailed description of the typical habitats of 8 Barbus species of Sri Lanka is given. The distribution of their typical habitats over the various waters leads to the grouping of species in associations. Quantitative analysis of catching data corroborates these groupings. Food competition and competition for spawning grounds is discussed following the species associations.

THE FEEDING HABITS OF MINNOWS OF THE GENUSBARBUS(PISCES, CYPRINIDAE) IN AFRICA, WITH SPECIAL REFERENCE TOBARBUS AIVOPLUSWEBER

SUMMARY A twelve month study of the feeding biology of the chubbyhead barb, Barbus anoplus, Weber, 1897, from Lake Le Roux on the Orange River is described. B. anoplus taken from the open-water habitat fed mainly on copepods and cladocerans whereas those living in a small stream fed mainly on aquatic insect larvae and had a more varied diet. Seasonal shifts in the diet for both juvenile and adult minnows were observed. The smaller length groups changed from benthic feeding in spring to mainly mid-water feeding in summer. The larger fish prey on corixids in sumer but switch to mainly chiro-nomid larvae and zooplankton in winter. The minnows fed actively during the day with peak feeding in mid-morning and at dusk. It is suggested that the euryphagous feeding behaviour of B. anoplus is partially responsible for the widespread distribution of this species in southern Africa and for the successful colonization of the new shoreline habitat of Lake Le Roux. A review of the feeding biology of small Barbus species...