Papers by Alexander Golubtsov
Comparative Cytogenetics
The Afrotropical lutefish family Citharinidae (Citharinoidei, Characiformes) comprises three gene... more The Afrotropical lutefish family Citharinidae (Citharinoidei, Characiformes) comprises three genera with eight species in total. Although Citharinidae have been studied in terms of taxonomy and systematics, no cytogenetic information was available for any representative of the family. Furthermore, only one species out of 116 in Citharinoidei (Distichodus affinis Günther, 1873) has been studied cytogenetically. Here, we report the karyotypes of Citharinus citharus (Geoffroy St. Hilaire, 1809) from West Africa and Citharinus latus Müller et Troschel, 1844 from Northeast Africa. The former has the diploid chromosome number 2n = 40 and the fundamental number FN = 80, while the latter has 2n = 44 and FN = 88. Hence, these karyotypes consist exclusively of bi-armed chromosomes. Such karyotypes were previously found in D. affinis and in many lineages of Neotropical species of another suborder of Characiformes, Characoidei. In contrast, the karyotypes dominated by uni-armed elements are typ...
Diversity
Trophic resource partitioning is one of the main ecological mechanisms of adaptive radiation. The... more Trophic resource partitioning is one of the main ecological mechanisms of adaptive radiation. The Garra is a highly specialized periphyton feeder that has widened jaws equipped with a horny cutting scraper. In a river located in the Ethiopian Highlands in East Africa, a diversification of Garra composed of six sympatric ecomorphs which were strikingly diverse in trophic morphology was revealed. A hypothesis on trophic resource partitioning was tested using data on diet composition, gut length, and stable isotopes. The obtained results confirmed the trophic diversification of Garra ecomorphs. Three feeding modes were revealed: (i) periphytonophagy, (ii) mixed periphytonophagy and zoophagy, and (iii) zoophagy. The periphyton feeders had a long gut and were enriched in δ13C values compared to the shorter gut and lowered δ13C values in the zoophagous ecomorphs. Therefore, Garra could respecialize out of its ancestral specialization. This finding does not support the generalists-to-speci...
The cyprinid tribe Labeonini (sensu Rainboth, 1991) is a large group of freshwater fishes contain... more The cyprinid tribe Labeonini (sensu Rainboth, 1991) is a large group of freshwater fishes containing around 40 genera and 400 species. They are characterized by an amazing diversity of modifications to their lips and associated structures. In this study, a total of 34 genera and 142 species of putative members of this tribe, which represent most of the generic diversity and more than one third of the species diversity of the group, were sampled and sequenced for four nuclear genes and five mitochondrial genes (totalling 9,465 bp). Phylogenetic relationships and subdivision of this tribe were investigated and the placement and status of most genera are discussed. Partitioned maximum likelihood analyses were performed based on the nuclear dataset, mitochondrial dataset, combined dataset, and the dataset for each nuclear gene. Inclusion of the genera Paracrossochilus, Barbichthys, Thynnichthys, and Linichthys in the Labeonini was either confirmed or proposed for the first time. None of the genera Labeo, Garra, Bangana, Cirrhinus, and Crossocheilus are monophyletic. Taxonomic revisions of some genera were made: the generic names Gymnostomus Heckel, 1843, Ageneiogarra Garman, 1912 and Gonorhynchus McClelland, 1839 were revalidated; Akrokolioplax Zhang and Kottelat, 2006 becomes a junior synonym of Gonorhynchus; the species Osteochilus nashii was found to be a member of the barbin genus Osteochilichthys. Five historical hypotheses on the classification of the Labeonini were tested and rejected. We proposed to subdivide the tribe, which is strongly supported as monophyletic, into four subtribes: Labeoina, Garraina, Osteochilina, and Semilabeoina. The taxa included in each subtribe were listed and those taxa that need taxonomic revision were discussed
Water, 2021
Trophic resource partitioning is one of the main drivers of adaptive radiation. The evolutionary ... more Trophic resource partitioning is one of the main drivers of adaptive radiation. The evolutionary diversification of large African barbs, the genus Labeobarbus, seems to be related to mouth polymorphism. The chisel-mouthed or scraping phenotype has repeatedly evolved within Labeobarbus. At least five ecomorphs with a scraping mouth morphology were detected in the waters of the Ethiopian Highlands and can be provisionally classified into two groups: (i) “Varicorhinus”-like, and (ii) “Smiling”-like. Previously, all Labeobarbus with a scraping-mouth morphology were considered to be periphyton feeders. Using data on morphology, diet and stable isotope ratios (C and N), we addressed the question: does a scraping-mouth morphology predict feeding on periphyton? Our study revealed that five scraper ecomorphs exhibited three main feeding modes: (i) periphyton-eating, (ii) herbivory–detritivory, and (iii) insectivory. Two cases of the parallel divergence of sympatric ecomorphs with distinct fe...
ABSTRACTThe phenomenon of a massive vertebral deformity was recorded in the radiatingLabeobarbusa... more ABSTRACTThe phenomenon of a massive vertebral deformity was recorded in the radiatingLabeobarbusassemblage from the middle reaches of the Genale River (south-eastern Ethiopia, East Africa). Within this sympatric assemblage, five trophic morphs – generalized, lipped, piscivorous and two scraping feeders – were reported between 1993 and 2019. In 2009, a new morph with prevalence of ∼10% was discovered. The new morph, termed ‘short’, had an abnormally shortened vertebral column and a significantly heightened body. This type of deformity is common in farmed Atlantic salmon and other artificially reared fish, but is rare in nature. In the GenaleLabeobarbusassemblage, the deformity was present exclusively within the generalized and lipped morphs. The short morph had between seven and 36 deformed (compressed and/or fused) vertebrae. Their body height was positively correlated with number of deformed vertebrae. In another collection in 2019, the short morph was still present at a frequency ...
Visnyk of the Lviv University. Series Geography, Dec 23, 2014
У статті обговорено результати середньомасштабного геоінформаційного картографування ландшафтів У... more У статті обговорено результати середньомасштабного геоінформаційного картографування ландшафтів України. Описано структуру ГІС "Ландшафти України", методичні прийоми, використані при формуванні геопросторової бази даних як складової створюваної ГІС. Приділено увагу змісту комплексної та компонентної інформації про ландшафти України. Розглянуто принципи систематизації та уніфікації даних для наповнення бази даних. Наведено приклади надання засобами ГІС інформації про ландшафтні комплекси рангу місцевість. Ключові слова: геоінформаційне картографування ландшафтів, структура ГІС "Ландшафти України", інформаційне забезпечення, база даних.
bioRxiv, 2021
Adaptive radiation of fishes was long thought to be possible only in lacustrine environments. Rec... more Adaptive radiation of fishes was long thought to be possible only in lacustrine environments. Recently, several studies have shown that also riverine and stream environments provide the ecological opportunity for adaptive radiation. In this study, we report on a riverine adaptive radiation of six ecomorphs of cyprinid hillstream fishes of the genus Garra in a river located in the Ethiopian Highlands in East Africa. Garra are predominantly highly specialized algae-scrapers with a wide distribution ranging from Southeastern Asia to Western Africa. However, adaptive phenotypic diversification in mouth type, sucking disc morphology, gut length and body shape have been found among these new species in a single Ethiopian river. Moreover, we found two novel phenotypes of Garra (‘thick-lipped’ and ‘predatory’) that were not described before in this species-rich genus (>160 species). Mitochondrial and genome-wide data suggest monophyletic, intra-basin evolution of Garra phenotypic diversi...
Comparative Cytogenetics
The African weakly electric elephantfish family Mormyridae comprises 22 genera and almost 230 spe... more The African weakly electric elephantfish family Mormyridae comprises 22 genera and almost 230 species. Up-to-date cytogenetic information was available for 17 species representing 14 genera. Here we report chromosome number and morphology in Hyperopisus bebe (Lacepède, 1803) and Pollimyrus isidori (Valenciennes, 1847) collected from the White Nile system in southwestern Ethiopia. Both taxa displayed the diploid chromosome number 2n = 40, but they differed in fundamental numbers: FN = 66 in H. bebe and FN = 72 in P. isidori; previously the same diploid chromosome number 2n = 40 was reported in an undescribed species of Pollimyrus Taverne, 1971 (FN = 42) from the same region. Our results demonstrate that not only pericentric inversions, but fusions also played a substantial role in the evolution of the mormyrid karyotype structure. If the hypothesis that the karyotype structure with 2n = 50–52 and prevalence of the uni-armed chromosomes close to the ancestral condition for the family ...
Comparative Cytogenetics
The elephantfish family Mormyridae is the most diverse lineage of the primitive teleostean clade ... more The elephantfish family Mormyridae is the most diverse lineage of the primitive teleostean clade Osteoglossomorpha distributed in inland waters of all continents except Antarctica and Europe. The family Mormyridae is endemic to Africa and includes 22 genera and almost 230 species. The evolutionary radiation of mormyrids most probably should be attributed to their capability of both generating and receiving weak electric signals. Up-to-date cytogenetic studies have revealed substantial karyotype differentiation among the nine investigated elephantfish species and genera (a single species studied per each genus). In the present study, karyotypes of five species representing five mormyrid genera (four unexplored ones) collected from the White Nile system in southwestern Ethiopia are described for the first time. The results show substantial variety of the diploid chromosome and fundamental numbers: 2n = 48 and FN = 54 in Brevimyrus niger (Günther, 1866), 2n = 50 and FN = 72 in Cyphomyr...
Frontiers in Marine Science
Frontiers in Marine Science
Large African barbs of the genus Labeobarbus are widely distributed in African freshwaters, and e... more Large African barbs of the genus Labeobarbus are widely distributed in African freshwaters, and exhibit profound phenotypic plasticity that could be a prerequisite for adaptive radiation. Using morphological, molecular, and stable isotope analyses, we investigated whether an adaptive radiation has occurred in a riverine assemblage of the L. gananensis complex. This complex is composed of six phenotypically distinct sympatric forms inhabiting the Genale River (Ethiopian highlands, East Africa). Of the six forms, five were divergent in their mouth morphology, corresponding to 'generalized', 'lipped', 'scraping' (two forms) and 'large-mouthed' phenotypes. Stable isotope analysis revealed differences in 15N and 13C among these forms, representing different foraging strategies (omnivorous, scraping and piscivorous). Phylogenetic analysis of two mtDNA markers confirmed the monophyly of L. gananensis, suggesting an intra-riverine radiation. However, the Gena...
Journal of Zoological Systematics and Evolutionary Research
Biogeographie des « grands Barbus » d'Ethiopie1 avec reference speciale a des formes a statuts ta... more Biogeographie des « grands Barbus » d'Ethiopie1 avec reference speciale a des formes a statuts taxinomiques incertains par A. S. GOLUBTSOV2 Communication ргёветё par M. MINA (Russie) Traduction de la version anglaise en frangais par P. BERREBI (Univ. Montpellier) SUMMARY : Biogeography of the large Barbus of Ethiopia with the special reference to forms of uncertain taxonomic status. During the period 1984-1993, four large Barbus species were sampled in the main water systems of southern Ethiopia. Based on the samples from Lake Tana and from the Genale River, evidence for the existence of Barbus species flocks is considered. RESUME Durant la periode 1984-1993, quatre especes appartenant au groupe des « grands Barbus » ont ete echantillonnees dans les principaux bassins hydrographiques d'Ethiopie. En se basant sur les echantillons du lac Tana et de la riviere Genale, la possibilite d'une formation de sous-unites taxinomiques (flocks) est analysee. Les bassins hydrographiques ethiopiens coulent vers deux mers. Au sud-est, le bassin du Wabi Shebeli coule vers Гocean Indien. A l'ouest du pays, les eaux coulent vers le Nil et la Mediterranee. Ces deux principaux bassins sont separes par la partie es; de la grande vallee du Rift africain. Dans sa partie ethiopienne, cette vallee contprend de nombreux systemes hydrographiques isoles depuis le bassins de l'Omo-Turkana au sud, jusqu'a celui d'Awash au nord (fig. 1).
The catfishes of the genus Clarias Scopoli, 1777,-are an important subject of fishery and aquacul... more The catfishes of the genus Clarias Scopoli, 1777,-are an important subject of fishery and aquaculture. This lends a particular importance to the recent revision of African members of the given group (Teugels, 1982, a,b,c 1986). The revision has been performed on the basis of the evidence from specimens and small samples from various localities of the African continent. Apparently the concepts of this study should be tested and complemented by research into the variability of taxonomically important characters in larger samples from different populations. According to the survey by Boulenger (1911) in the White Nile Basin, the genus Clarias is represented by two species: C. anguillaris (Linnaeus, 1758) and C. lazera Cuvier et Valenciennes, 1840. The present communication provide comparative data on the variability of the number of gill rakers, the number of fin rays, the relative length of the head, and also the variability of the shape of vomerine toothplate in the catfishes of these species in the river system of Baro-Akobo (east tributaries of the White Nile). The evidence from this region is not used in the above-mentioned revision (Teugels, 1982c, 1986). Material and Method The material for the present communication was collected in November 1986-January 1987 in the basins of the rivers Alvero and Gilo. The numbers, geographical situation and description of the stations, as well as catching methods were given in the paper by A.S. Golubtsov et al. (see the present collected papers). A total of 106 fishes obtained from the following localities were analyzed: Station I-C. anguillaris n = 22 standard length (SL) 192-725mm; C. gariepinus n = 52 SI 130-420mm; Station III-C. anguillaris n = 6 SL 600-840mm; C. gariepinus n = 22 SL 740-730mm;
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Papers by Alexander Golubtsov