Reconstruction of the evolutionary history of the brown trout complex Salmo cf. trutta of the Western Balkans: differentiation and diversity

Filogenija i sistematika u drugoj polovini 20. veka sve više se zasnivaju na molekularnim metodama kojima se nastoje rešiti kompleksni odnosi između rodova i vrsta u okviru porodice Salmonidae. U ovom radu, kao molekularno-genetički markeri korišćeni su kontrolni region mitohondrijalne DNK (CR mtDNK), mikrosateliti i jedarni LDH-C* gen, važan dijagnostički marker koji se dobro pokazao u rešavanju problema postglacijalne kolonizacije populacija S. trutta. Krajem 20. veka definisane su jasne filogeografske linije pastrmki – atlantska (AT), dunavska (DA), mediteranska (ME), jadranska (AD) i marmoratus linija (MA). Zapadni deo Balkana čini jadransko-mediteranska oblast sa najvećim fenotipskim diverzitetom među pastrmskim populacijama, dok veliki deo unutrašnje teritorije pripada crnomorskom slivu. U ovoj disertaciji analizirane su potočne pastrmke iz reka crnomorskog sliva u Bosni i Hercegovini, i reka jadranskog sliva u Crnoj Gori, sa ciljem utvrđivanja genetičke strukture i raznovrsnosti populacija kompleksa S. cf. trutta na području zapadnog Balkana, uzimajući u obzir potencijalne hibridizacione procese. U rekama crnomorskog sliva detektovana su dva haplotipa DA (Da2, Da22), i jedan AT linije (At1). U jadranskom slivu ustanovljeno je šest haplotipova iz tri linije: AD (ADcs11, Ad+Prz), DA (Da1, Da2) i AT (A17, At1). U gotovo svim rezidentnim populacijama primećeno je ukrštanje između autohtonih i introdukovanih jedinki. Invazivni efekti stranih haplotipova potočne pastrmke (At1, A17, Da2) u analiziranim rekama otkriveni su u proceni rizika od strane autora navedenih u ovoj disertaciji. Nužno je ustanoviti politiku upravljanja pastrmskim ribolovom i mere konzervacije kako bi se redukovao rizik koji neadekvatno poribljavanje predstavlja po autohtoni fond potočne pastrmke.Phylogeny and systematics in the second half of the 20th century are mostly based on molecular methods that seek to resolve complex relationships between genera and species within the Salmonidae family. In this research, the following molecular molecular genetic markers were used: mitochondrial DNA (CR mtDNA) control region, microsatellites and nuclear LDH-C * gene, an important diagnostic marker that has proven particularly well for addressing postglacial colonization of S. trutta populations. At the end of the 20th century clear phylogeographic lineages of brown trout were defined – Atlantic (AT), Danubian (DA), Mediterranean (ME), Adriatic (AD), and marmoratus (MA). Western part of Balkan is made up of the Adriatic-Mediterranean area, which represents the area of greatest phenotypic diversity among trout populations, while a large part of the its inland territory belongs to the Black Sea basin. In this dissertation, brown trout from the rivers of the Black Sea basin in Bosnia and Herzegovina, and the rivers of the Adriatic basin in Montenegro were analyzed, with the aim of determining the genetic structure and diversity of populations of the complex of brown trout S. cf. trutta in the Western Balkans, taking into account potential hybridization processes. In rivers of the Black Sea basin, three haplotypes were detected, two of which belong to the DA lineage (Da2 and Da22), and one haplotype belongs to the AT lineage (At1). Six haplotypes from three lineages were detected in the Adriatic basin: AD (ADcs11, Ad + Prz), DA (Da1, Da2) and AT (A17, At1). In almost all resident populations, crossing between autochthonous and introduced individuals was observed. The invasive effects of foreign haplotypes of brown trout (At1, A17, Da2) in analyzed trout rivers were discovered in a risk assessment by the authors cited in this dissertation. There is a great need to establish a trout fisheries management policy and conservation measures to reduce the possible risk that inadequate stocking may pose to an indigenous trout stock

SOCIJALNE, EKONOMSKE, RIBARSTVENE I KONZERVACIJSKE ODLIKE MUŠIČARENJA U SRBIJI

Modern fly fishing, mainly for brown trout and grayling, has been done on a local scale and in low extensity in Serbia for over 50 years. Data obtained from 117 fly fishermen filling out an online questionnaire, with 30 questions processed using multivariate analysis, revealed that most fishermen who had started fly fishing since 2000 were under 40. Only few who were under 20 started to fish initially with the fly fishing equipment. They turned up committed to and skilled in fly fishing. Most of them live in large municipalities with much better economic opportunities. Their level of education is above average in Serbia. Economic power, place of residence and level of education outline their fishing capabilities, frequency of fishing outings, distance they travel to fly fish, as well as their attitudes towards fishery policy, conservation of native brown trout and grayling stocks, management of streams and communication with other fly fishermen.Suvremeno mušičarenje, prije svega potočne pastrve i lipljena, postoji više od 50 godina u Srbiji na lokalnom nivou i slabog je intenziteta. Podaci od 117 mušičara dobiveni anketiranjem upitnikom sastavljenim od 30 pitanja putem Interneta, analizirani multivarijatno, pokazali su da je većina onih koji su počeli mušičariti od 2000. godine starosti ispod 40 godina. Samo mali broj onih mlađih od 20 godina mušičari su od početka bavljenja ribolovom. Svi anketirani pojedinci vrlo su posvećeni mušičarenju i posjeduju potrebne mušičarske vještine. Veliki dio njih živi u velikim gradovima gdje postoje bolje ekonomske mogućnosti. Njihov obrazovni nivo je iznad prosječnog u Srbiji. Ekonomska moć, mjesto stanovanja i obrazovni nivo određuju njihove mogućnosti za ribolov, učestalost odlaska na ribolov, daljinu na koju putuju radi ribolova, kao i njihove stavove prema ribarstvenoj politici, očuvanju autohtonih fondova potočne pastrve i lipljena, ribarstvenom upravljanju pastrvskim i lipljenskim vodama i komunikaciji s drugim mušičarim

Effect of the introgression of Atlantic brown trout, Salmo trutta, into Adriatic trout, Salmo farioides in a stream at the drainage area of the Adriatic Sea basin of Montenegro

Background. The diversity of wild trout stocks in Montenegro is compromised by insufficiently controlled stocking. Adriatic and Mediterranean areas show a high degree of endemism of the salmonid species, with numerous native Salmo taxa described. The invasive effect of brown trout, Salmo trutta Linnaeus, 1758, of the Atlantic haplogroup on the endemic Adriatic trout, Salmo farioides Karaman, 1938, in the drainage area of the Adriatic Sea basin is lower compared to the effect inflicted by S. trutta has on Salmo labrax Pallas, 1814 of the Danubian haplogroup. The presently reported study was intended to describe the genetic structure of the population of Adriatic trout, Salmo farioides, from the Mrtvica River, a right tributary of the Morača River, Montenegro, in order to get an insight into the spread of non-native strains and their introgression into the native Adriatic trout gene pool. Materials and methods. Trout specimens sampled from the lower section of the Mrtvica River from 2004 to 2007, and from its upper section in the spring of 2014, were analysed for their mtDNA haplotypes. Nuclear DNA markers (microsatellites, LDH-C1* gene) were also included in genetic analyses since mtDNA is inherited only maternally. After statistical analyses, relations between individuals from the upper and lower Mrtvica River were reconstructed. Results. Using both LDH-C1* and seven microsatellite loci with several alleles exclusive to S. trutta, an introgression was detected only in the upper reaches of the Mrtvica River, where only stream-dwelling trout form occurs. In the lower reaches no introgression was detected at all, as revealed by the absence of both the Atlantic mitochondrial haplotype and microsatellite alleles exclusive to S. trutta. Conclusion. The allelic frequency at seven microsatellite loci of Salmo spp. from the two river sections revealed very different population structure, as a consequence of a low rate of gene flow between them. In addition to the physical barrier that prevents Salmo sp. from the lower Mrtvica River to migrate to the upper river section, it seems that the opportunity to mate with the large pool of conspecifics, including lake-dwelling S. farioides (i.e., Salmo cf. dentex), prevents Salmo trutta from surviving at the lower stretch and spread to the rest of the Morača River and Lake Skadar systems

Reconstruction of the evolutionary history of the brown trout complex Salmo cf. trutta of the Western Balkans: differentiation and diversity

Filogenija i sistematika u drugoj polovini 20. veka sve više se zasnivaju na molekularnim metodama kojima se nastoje rešiti kompleksni odnosi između rodova i vrsta u okviru porodice Salmonidae. U ovom radu, kao molekularno-genetički markeri korišćeni su kontrolni region mitohondrijalne DNK (CR mtDNK), mikrosateliti i jedarni LDH-C* gen, važan dijagnostički marker koji se dobro pokazao u rešavanju problema postglacijalne kolonizacije populacija S. trutta. Krajem 20. veka definisane su jasne filogeografske linije pastrmki – atlantska (AT), dunavska (DA), mediteranska (ME), jadranska (AD) i marmoratus linija (MA). Zapadni deo Balkana čini jadransko-mediteranska oblast sa najvećim fenotipskim diverzitetom među pastrmskim populacijama, dok veliki deo unutrašnje teritorije pripada crnomorskom slivu. U ovoj disertaciji analizirane su potočne pastrmke iz reka crnomorskog sliva u Bosni i Hercegovini, i reka jadranskog sliva u Crnoj Gori, sa ciljem utvrđivanja genetičke strukture i raznovrsnosti populacija kompleksa S. cf. trutta na području zapadnog Balkana, uzimajući u obzir potencijalne hibridizacione procese. U rekama crnomorskog sliva detektovana su dva haplotipa DA (Da2, Da22), i jedan AT linije (At1). U jadranskom slivu ustanovljeno je šest haplotipova iz tri linije: AD (ADcs11, Ad+Prz), DA (Da1, Da2) i AT (A17, At1). U gotovo svim rezidentnim populacijama primećeno je ukrštanje između autohtonih i introdukovanih jedinki. Invazivni efekti stranih haplotipova potočne pastrmke (At1, A17, Da2) u analiziranim rekama otkriveni su u proceni rizika od strane autora navedenih u ovoj disertaciji. Nužno je ustanoviti politiku upravljanja pastrmskim ribolovom i mere konzervacije kako bi se redukovao rizik koji neadekvatno poribljavanje predstavlja po autohtoni fond potočne pastrmke.Phylogeny and systematics in the second half of the 20th century are mostly based on molecular methods that seek to resolve complex relationships between genera and species within the Salmonidae family. In this research, the following molecular molecular genetic markers were used: mitochondrial DNA (CR mtDNA) control region, microsatellites and nuclear LDH-C * gene, an important diagnostic marker that has proven particularly well for addressing postglacial colonization of S. trutta populations. At the end of the 20th century clear phylogeographic lineages of brown trout were defined – Atlantic (AT), Danubian (DA), Mediterranean (ME), Adriatic (AD), and marmoratus (MA). Western part of Balkan is made up of the Adriatic-Mediterranean area, which represents the area of greatest phenotypic diversity among trout populations, while a large part of the its inland territory belongs to the Black Sea basin. In this dissertation, brown trout from the rivers of the Black Sea basin in Bosnia and Herzegovina, and the rivers of the Adriatic basin in Montenegro were analyzed, with the aim of determining the genetic structure and diversity of populations of the complex of brown trout S. cf. trutta in the Western Balkans, taking into account potential hybridization processes. In rivers of the Black Sea basin, three haplotypes were detected, two of which belong to the DA lineage (Da2 and Da22), and one haplotype belongs to the AT lineage (At1). Six haplotypes from three lineages were detected in the Adriatic basin: AD (ADcs11, Ad + Prz), DA (Da1, Da2) and AT (A17, At1). In almost all resident populations, crossing between autochthonous and introduced individuals was observed. The invasive effects of foreign haplotypes of brown trout (At1, A17, Da2) in analyzed trout rivers were discovered in a risk assessment by the authors cited in this dissertation. There is a great need to establish a trout fisheries management policy and conservation measures to reduce the possible risk that inadequate stocking may pose to an indigenous trout stock

Invasiveness assessment of the Chinese mitten crab Eriocheir sinensis (H. Milne Edwards, 1853) in the Serbian section of the river Danube

The Chinese mitten crab Eriocheir sinensis is listed in The Global Invasive Species Database and the IUCN Register as one of “100 of the world’s worst invasive alien species”. It has been reported in Serbia since 1995 in the Danube River, suggesting a predominantly human-aided dispersal. The risk of invasiveness posed by the Chinese mitten crab to aquatic ecosystems in Serbia, assessed using the FI-ISK (Freshwater Invertebrate Invasiveness Scoring Kit, v1.19), revealed a final score of 37. This shows a high potential of invasiveness, mainly due to its versatile ecological and biological features in a climate similar to that in the donor area. FI-ISK assessment revealed the alleged environmental impact of Chinese mitten crab in Serbia to be of much greater impact on aquaculture than previously assumed

Determination of resident brown trout Salmo trutta features by their habitat characteristics in streams of Serbia

Streams’ order, their width and depth, as well as the water temperature, conductivity, dissolved oxygen contents and pH reaction were recorded for 18 streams of the Danube River basin in Serbia that home brown trout Salmo trutta. For each of them, the number of fish species was recorded, and for brown trout in them the number of cohorts, age-structure, productivity (biomass, annual production and average weight) and growth (von Betalanffy’s growth parameters L∞, t0, K and ø’) were calculated. They were examined in relation to stream’s habitat features. Stepwise multiple regression revealed strong interdependence between habitat variables. Size, i.e., width and depth of streams increased and their oxygen content dropped with increase in their order and rise of the water temperature, and water conductivity was strongly interrelated with order and depth of streams. Increase in streams’ order and their water’s temperature were accompanied with the increase of species number in them, number of brown trout cohorts raised with the water conductivity and dropped with the increase of the alkaline pH value of streams, whereas growth of brown trout was determined by width of streams and their water’s conductivity. However, when analyzed one at a time, very few of habitat and population traits, e.g., stream depth and L∞, varied clearly in streams of either various orders, or conductivity classes, respectively. The notable, but not yet significant variability of almost all other characters implicates their strong and complex acting in concert to determining number of fish species in syntopy, brown trout population, productivity and growth features

Status and Perspectives of the Ichthyofauna of the Labudovo okno Ramsar Site: An Analysis of 14 Years of Data

Over the last 14 years, ichthyological and ecological parameters have been monitored in the Labudovo okno Ramsar site. This area is important for its biodiversity as it is home to many rare and endangered plants and animal species. A total of 3861 fish specimens were sampled and measured at six sampling sites four times during the sampling period. An analysis of biodiversity indexes, relative biomass (kg/ha), and relative annual production (kg/ha) was carried out to assess the effectiveness of existing conservation measures. The results obtained show a trend decline in biodiversity, relative biomass, and relative annual production. This indicates a biodiversity conservation problem that should be addressed through other mechanisms in addition to the principles of the Ramsar Convention

A treatise about reliability in dating events of evolutionary history of brown trout Salmo cf. trutta (Actinopterygii) at Western Balkans: Impassable barriers, isolation of populations and assistance of geological timeframe

A pool of data already existing about D-loop, i.e., the Control Region (CR) haplotypes of the mitochondrial DNA (mtDNA) of brown trout, Salmo trutta Linnaeus, 1758, tentative Adriatic trout Salmo farioides Karaman, 1938, and tentative Macedonian trout, Salmo macedonicus (Karaman, 1924), and their reconstructed phylogeography makes a good starting point for resolving their evolutionary history. That includes the dating of particular events in it. The events have hitherto been dated using the method of a molecular clock. Various calibrations were applied for the mutation rate, owing to the incongruence between the time of divergence that various authors notified and general knowledge about events in geological history and the periods in which they occurred in the Mediterranean region. Since geological history events were mandatory for setting the scene for the evolutionary history of brown trout, the incongruence between them has questioned the molecular clock calibration’s validity. From results about both the phylogeography and phylogenetic relations between native haplotypes (both partial and whole CR sequences) and the population genetics that characterized particular populations, we calculated the time of divergence between haplotypes in the regions of the western part of the Balkans: Iron Gate broader area in eastern Serbia, continental Montenegro and south-eastern Serbia. The distinct status of adjacent populations was verified by frequencies of microsatellites’ alleles and the STRUCTURE analysis that examined the significance of differences between them. In particular, we examined the populations that were clearly separated either by physical barriers, such as a waterfall in eastern Serbia (e.g., the upper and lower River Rečka supplemented by nearby rivers Vratna and Zamna), or by underground drops in Montenegro (e.g., upper and lower River Zeta, and rivers Nožica and lower River Mrtvica as isolated counterparts). We used the so far most common substitution rate of 1% in a million years’ (MY) period. The divergence times we obtained were compared to the events known for the region from available geological history data. There was a fairly good congruence between the dating obtained by the molecular clock method and that by geological history where the advanced, i.e., modern haplotypes, were concerned. In contrast, the congruence was worse for dating of divergence when more ancient haplotypes were in question, being much better if the mutational rate would be decreased to lower rates. That supported results both from the Rate Correlation Test about the independence of evolutionary rates in different lineages of brown trout, and from the Molecular Clock Test, which revealed that the evolutionary rate throughout the phylogenetic tree is not equal. That implies a difference in the speed of evolution in them, which was likely slower and faster, in the ancient, pre-Pleistocene haplotypes and the advanced, Pleistocene ones, respectively. The setting of the variable, or non-linear (i.e., logarithmic) speed of evolving seems helpful, since the early cladogenesis with the dominance of mutations was most likely combined afterwards with the acting of other evolutionary mechanisms, especially of genetic drift in populations that passed through the bottleneck episodes of the abrupt decrease in population size during the unfavourable periods of their evolutionary history

Changing climate may mitigate the invasiveness risk of non-native salmonids in the Danube and Adriatic basins of the Balkan Peninsula (south-eastern Europe)

Salmonids are an extensively hatchery-reared group of fishes that have been introduced worldwide mainly for their high commercial and recreational value. The Balkan Peninsula (south-eastern Europe) is characterised by an outstanding salmonid diversity that has become threatened by the introduction of non-native salmonids whose potential risk of invasiveness in the region remains unknown and especially so under predicted climate change conditions. In this study, 13 extant and four horizon non-native salmonid species were screened for their risk of invasiveness in the Danube and Adriatic basins of four Balkan countries. Overall, six (35%) of the screened species were ranked as carrying a high risk of invasiveness under current climate conditions, whereas under predicted conditions of global warming, this number decreased to three (17%). Under current climate conditions, the very high risk (‘top invasive’) species were rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta (sensu stricto), whereas under predicted climate change, this was true only of O. mykiss. A high risk was also attributed to horizon vendace Coregonus albula and lake charr Salvelinus namaycush, and to extant Atlantic salmon Salmo salar and brook trout Salvelinus fontinalis, whose risk of invasiveness, except for S. fontinalis, decreased to medium. For the other eleven medium-risk species, the risk score decreased under predicted climate change, but still remained medium. The outcomes of this study reveal that global warming will influence salmonids and that only species with wider temperature tolerance, such as O. mykiss will likely prevail. It is anticipated that the present results may contribute to the implementation of appropriate management plans to prevent the introduction and translocation of non-native salmonids across the Balkan Peninsula. Additionally, adequate measures should be developed for aquaculture facilities to prevent escapees of non-native salmonids with a high risk of invasiveness, especially into recipient areas of high conservation value