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Locations of S. maximus sampling sites: TRB (Trabzon coast); DUZ (Duzce coast); VAR (Bulgarian Varna coast); SVT (Russian Sevastopol coast); MAR (the Marmara Sea coast).
Source publication
Genetic structuring of turbot (Scophthalmus maximus) stocks from Turkish, Bulgarian and Russian coasts in the Black and Marmara Seas was evaluated through the application of five polymorphic microsatellites and one mitochondrial DNA (COIII region) markers. The microsatellite analysis indicates two genetic separations – one is the Marmara Sea popula...
Citations
... Spatial information on fisheries resources underpins sustainable management; moreover, in the last years, genetic methods for defining stock boundaries are well developed (Ovenden et al. 2015). Molecular markers have already been applied for determination of the S. maximus population structure in the Black Sea (Atanassov et al. 2011, Nikolov et al. 2015, Turan et al. 2019, Bessonova & Nebesikhina 2019, Firidin et al. 2020, Ivanova et al. 2020. Turbot inhabiting the northern part of the Black Sea showed significant genetic differences in comparison to fishes inhabiting the south-eastern and southwestern parts of the Black Sea shelf (Firidin et al. 2020). ...
... Morphometric characters analysed (afterTuran et al. 2019). Legend: 1. Linea -Dorsal height; 2. Linea -Anal height. ...
Morphometric and meristic characters of fish are important for species differentiation, overall stock status assessment, in the analysis of the population structure and genetic variations within and between populations and as an indicator for utilization of environmental resources or habitat diversity. Comparative analysis of morphometric and meristic characters of Scophthalmus maximus L. sampled in the regions of Shabla, Shkorpilovtsi, Nesebar and Tsarevo along the Bulgarian Black Sea coast was carried out. Selected growth models as length-weight relationship (LWR) and relationships and ratios as standard length (SL)-total length (TL), head length (HL)-body depth/height (BD/BH), BD/BH-SL were studied, aiming at identification of specific or significant differences in the sampled specimens and indirect differentiation of specific environment constraints in species habitat. The studied turbot populations demonstrated considerable intra-species morphometric variations, which are further to be justified by thorough analysis of genetic diversity at a local and regional level. Environmental differences between sites in the sampling period have not been recorded and the species habitat appeared to be homogenous in terms of abiotic environment.
... There are few case studies addressing turbot stock assessments [25] along the Bulgarian Black Sea coast, and data on the species' spatiotemporal distribution and habitat suitability are limited. For a small number of populations, genetic diversity throughout the Bulgarian Black Sea coast was assessed using mitochondrial markers [26,27]. However, no studies have been conducted to analyze the temporal decline in genetic diversity and the loss of genetic variation associated with harvesting in the past due to a lack of genetical monitoring. ...
... Overall, most locations exhibited moderate to high haplotype diversity (0.363-0.783) due to a large number of unique haplotypes. The mean haplotype diversity (Hd = 0.577) of turbot along the Black Sea coast was close to that reported by [26] for the same species (Hd = 0.550), and higher than that (0.380) published by [27]; however, the nucleotide diversity was relatively low, ranging from 0.00128 to 0.00233. ...
The present study examined the genetic diversity and spatial distribution of turbot (Scophthalmus maximus), an economically important species on the Bulgarian Black Sea coast. Maximum entropy (MaxEnt) modeling software Version 3.4.4. was utilized to develop a habitat suitability model for S. maximus in the Bulgarian Black Sea region. Data collected via demersal and pelagic surveys and genetic sampling from 2017 to 2021 were utilized to link species occurrence localities with selected abiotic factors. Our findings showed that the species’ habitat preferences are strongly influenced by temperature and dissolved oxygen, and projections based on simplified climatic scenarios indicated potential distribution shifts and a substantial reduction in reproduction habitats in the northern region. The assessment of genetic diversity was based on mtDNA COIII sequencing; MtDNA revealed a low level of polymorphism in all analyzed populations. The extensive fishing pressure may have increased the likelihood of genetic and population bottlenecks and a consequent decline in genetic diversity in the Shabla, Nesebar, and Tsarevo populations. The Tajima’s D values for the latter indicated that turbot underwent a bottleneck followed by rapid population expansion. Our findings are essential for the conservation and effective management of S. maximus stocks in the region.
... Molecular markers (microsatellites and mtDNA) were applied only to closely-related turbot species in different marine regions in order to assess the genetic diversity (Bouza et al. 2002;Suzuki et al. 2004;Vandamme et al. 2014Vandamme et al. , 2020do Prado et al. 2018). Thus, using these molecular markers, limited data on the population structure of S. maximus in the Black Sea were obtained (Atanassov et al. 2011;Nikolov et al. 2015;Bessonova and Nebesikhina 2019;Turan et al. 2019b;Firidin et al. 2020;Ivanova et al. 2020). ...
... The Shabla, Nesebar and Shkorpilovtsi populations had the smallest number of alleles per Smax-02 locus in comparison with all Black Sea populations previously investigated (Table 2). For the other loci, the data obtained were similar (Turan et al. 2019b;Bessonova and Nebesikhina 2019;Firidin et al. 2020). The most polymorphic locus in the current study was Sma-USC26 in the Shabla population (Table 2). ...
... Nucleotide diversity ranged from 0.001 to 0.002. The result of mean COIII haplotype diversity between populations was 0.550, higher than the data presented in Turan et al. (2019b) for five populations in the Black and Marmara Seas (0.380). For the control region (CR), haplotypes (H1, 2 and 4) were common for the three populations analysed (Fig. 3) Unique CR haplotypes were observed in all populations, i.e. ...
Turbot ( Scophthalmus maximus L., 1758) is a valuable commercial fish species classified as endangered. The conservation and sustainability of the turbot populations require knowledge of the population’s genetic structure and constant monitoring of its biodiversity. The present study was performed to evaluate the population structure of turbot along the Bulgarian Black Sea coast using seven pairs of microsatellites, two mitochondrial DNA (COIII and CR) and 23 morphological (15 morphometric and 8 meristic) markers. A total of 72 specimens at three locations were genotyped and 59 alleles were identified. The observed number of alleles of microsatellites was more than the effective number of alleles. The overall mean values of observed (Ho) and expected heterogeneity (He) were 0.638 and 0.685. A high rate of migration between turbot populations (overall mean of Nm = 17.484), with the maximum value (19.498) between Shabla and Nesebar locations, was observed. This result corresponded to the low level of genetic differentiation amongst these populations (overall mean Fst = 0.014), but there was no correlation between genetic and geographical distance. A high level of genetic diversity in the populations was also observed. The average Garza-Williamson M index value for all populations was low (0.359), suggesting a reduction in genetic variation due to a founder effect or a genetic bottleneck. Concerning mitochondrial DNA, a total number of 17 haplotypes for COIII and 41 haplotypes for CR were identified. The mitochondrial DNA control region showed patterns with high haplotype diversity and very low nucleotide diversity, indicating a significant number of closely-related haplotypes and suggesting that this population may have undergone a recent expansion. Tajima’s D test and Fu’s FS test suggested recent population growth. Pairwise Fst values were very low. The admixture and lack of genetic structuring found pointed to the populations analysed probably belonging to the same genetic unit. Therefore, a proper understanding and a sound knowledge of the level and distribution of genetic diversity in turbot is an important prerequisite for successful sustainable development and conservation strategies to preserve their evolutionary potential.
... В настоящее время, на основании современных морфологических (Chanet, 2003) и молекулярно-генетических (Bailly, Chanet, 2010;Vandamme et al., 2014;Turan et al., 2019) исследований, можно считать (но пока ещё не окончательно), что черноморский калкан и атлантический тюрбо являются разными географическими группировками одного вида, Scophthalmus maximus, однако, вероятно, черноморский калкан является подвидом, произошедшим от одного общего предка с тюрбо в поздние геологические эпохи до последнего ледникового периода, или, возможно, из-за долгого периода географической изоляции при полном отсутствии обмена генами с популяциями тюрбо на протяжении последних 190 тысяч лет калкана можно будет считать отдельным видом (Avise, 2000). Однако до настоящего времени не было проведено ни одного эксперимента по скрещиванию черноморского калкана и атлантического тюрбо и получению от них потомков, способных к воспроизводству, что окончательно бы подтвердило их конспецифичность. ...
... Одним из видов высокорейтинговых ценных культивируемых рыб, как на европейском, так и на других рынках, считается атлантическая камбала тюрбо Psetta maxima (или Scophthalmus maximus), вид близкородственный (или, как считается в настоящее время, конспецифичный) черноморской камбале калкан (Turan et al., 2019). Только страны ЕС осваивают 15 тыс. ...
This book resumes many years of research experience of the authors and their colleagues, as well as numerous European and Chinese experimental and field studies on the developmental biology and physiology of valuable commercial fish, the Black Sea kalkan (Scophthalmus maeoticus) and the Atlantic turbot (Scophthalmus maximus), closest relatives and, according to modern genetic research, presumably, one species. The history of formation of currently powerful industrial turbot aquaculture presented in this book is based on the analysis of numerous scientific and applied research on turbot mariculture and economic features of formation of its European, in particular, Spanish and Chinese clusters. Recommended for researchers – biologists and biotechnologists, university professors, students of biological and biotechnology specialties, specialists in aquaculture, fish farming, ecology, as well as for a wider range of readers, managers, economists and operators of aquaculture enterprises.
Genetic structure and some bio-ecological characteristics of lessepsian lizardfish Saurida lessepsianus populations collected from the Iskenderun, Mersin, and Antalya Bays were revealed by mtDNA sequencing of Cyt b dataset and length-weight relationships and the parameters of von Bertalanffy growth function. The highest genetic divergence was detected between the Mersin and Antalya populations (0.0026), whereas the lowest was between the Iskenderun and Antalya populations (0.0014). The length-weight relationships for all individuals of Iskenderun, Mersin, and Antalya populations were calculated as W = 0.0042 x L 3.2207 , W = 0.0039 x L 3.1627 and W = 0.0196 x L 2.6515 , respectively. The von Bertalanffy growth parameters (L∞, k, and to) were estimated for all individuals as L∞ = 47.33 cm, k = 0.024, and to =-1.28 for Iskenderun; L∞ = 41.74 cm, k = 0.085 and to =-1.72 for Mersin and L∞ = 50.99 cm, k = 0.154 and to =-2.41 for Antalya. This study examines the genetic structure and bio-ecological characteristics of the S. lessepsianus populations on the Mediterranean coast of Türkiye together for the first time. Genetic findings and bio-ecological parameters of populations generally support each other and can provide support for future studies.
Memoriam
Dr. Mevlüt GÜRLEK’in hatırasına (1975-2022)
https://www.cappadociapublishing.com/index.php/ish/article/view/24
Non-synonymous variation (NSV) of protein coding genes represents raw material for selection to improve adaptation to the diverse environmental scenarios in wild and livestock populations. Many aquatic species face variations in temperature, salinity and biological factors throughout their distribution range that is reflected by the presence of allelic clines or local adaptation. The turbot (Scophthalmus maximus) is a flatfish of great commercial value with a flourishing aquaculture which has promoted the development of genomic resources. In this study, we developed the first atlas of NSVs in the turbot genome by resequencing 10 individuals from Northeast Atlantic Ocean. More than 50,000 NSVs where detected in the ~ 21,500 coding genes of the turbot genome, and we selected 18 NSVs to be genotyped using a single Mass ARRAY multiplex on 13 wild populations and three turbot farms. We detected signals of divergent selection on several genes related to growth, circadian rhythms, osmoregulation and oxygen binding in the different scenarios evaluated. Furthermore, we explored the impact of NSVs identified on the 3D structure and functional relationship of the correspondent proteins. In summary, our study provides a strategy to identify NSVs in species with consistently annotated and assembled genomes to ascertain their role in adaptation.
The combined analysis of biological characteristics and sperm traits of wild turbot males during spawning periods from mid-April to mid-June 2008, 2010, 2012–2014 in the local populations at the depths 50–95 m in the Northern Black Sea was carried out on the basis of the gillnet catches. Only mature males were observed during all sampling months and years. Gonadosomatic index of mature males with total body length 36–64 cm (aged 3–13-years-old) varied within 0.2–2.6. Sperm volume stripped from spermiating males ranged from 0.3 to 7.5 ml; sperm density and relative stripped production of spermatozoa fall in the range of 0.2–11 × 10⁹ ml⁻¹ and 0.4–46 × 10⁹ per male, correspondingly. Principal component analysis indicated that neither biological characteristics of males, nor the phase of the spawning season impact the percentage of motile spermatozoa and сurvilinear velocity VCL in activated sperm. However, the best sperm traits (significantly higher, p < 0.05, than that of the sperm traits of males in other years) with average percentage of motile spermatozoa 95% (73 – 99.8%), average VCL 140 µm.s⁻¹ (92–222 µm.s⁻¹) was determined for males in 2010.
Turbot (Scophthalmus maximus (L.)) is regarded as a good quality product that enjoys widespread acceptance and is therefore a popular choice for marine aquaculture in Europe. This study examines the potential and feasibility of the artificial cultivation of turbot in the Baltic Sea region. It takes into consideration both commercial farming and the implementation of artificial reproduction for stock enhancement programs. With regard to the latter, it discusses observed short-term trends towards reducing species catches in ICES 22-32 subdivisions as well as trends in hydrological process dynamics during the spawning process (especially low water salinity, which decreases the natural reproduction efficiency). The article also considers the potential of the research performed in 2018−2019 at the AtlantNIRO research facility on the development of cultivation techniques for turbot larvae. The findings demonstrate the possibility of cultivating turbot larvae under artificial conditions and are important for the development of marine aquaculture in the Kaliningrad region of Russia, since they can lead to the introduction of new fish species for farming in the future.
Peniophora proxima Bres. is corticioid fungus belonging to family
Peniophoraceae (Basidiomycota). It is easily distinguished by the numerous
encrusted cystidia, gloeocystidia and ellipsoid spores. The species is considered
a common white rot saprobe restricted only to the Buxus representatives.
One of the most popular species of the Old world is Buxus sempervirens L.
(European boxwood), native to western and southern Europe, northwest Africa,
and southwest Asia. Although the species does not belong to the native flora of
Bulgaria, for many years, the European boxwoods have been one of the most
popular and widely used landscaping plants, in the form of ornamental shrubs
or dense, evergreen hedges in shady places. P. proxima has been reported from
different parts of Europe, but it has not been previously reported for Bulgaria.
This article reports this new find from three localities in Bulgaria, while providing
information about the morphological and ecological features of the species and
commenting on the pattern of its distribution.
Keywords: first record, Bulgarian mycota, Buxus sempervirens, lignicolous
fungi.
