Sunbleak Leucaspius Delineatus Research Articles

A rapid assessment of non-native fish distributions in two English river basins using environmental DNA

Environmental DNA (eDNA) surveys are increasingly used to inform management decisions for non-native species, for example, by detecting the presence and plotting distributions of species that may be in too low abundance for easy detection by conventional means. A recently-developed nested PCR protocol was used to assess the distributions of three non-native fish species in two river basins of southern England (River Test, Hampshire; River Ouse, Sussex). These river basins were known to contain three non-native fishes, either in the recent past or currently: two invasive small-bodied fish species (topmouth gudgeon Pseudorasbora parva, sunbleak Leucaspius delineatus), as well as a currently non-invasive species predicted to become invasive under future climate conditions, pumpkinseed Lepomis gibbosus. Water samples were collected at locations from headwater streams to estuary. Pumpkinseed and sunbleak were both detected downstream of an angling venue in the Sussex Ouse catchment known to contain those species, with an upstream expansion of sunbleak suggested by the detection of eDNA at a few upstream locations. Neither sunbleak nor topmouth gudgeon was detected in water samples from the River Test catchment, suggesting that neither species has persistent populations in that river catchment.

Taste Preferences of Cyprinid Fishes (Cyprinidae). A Comparative Study

Palatability of various substances (amino acids, carboxylic acids, some organic acids, and basic taste substances) is presented for eight species of cyprinids (Cyprinidae): bream Abramis brama, European bitterling Rhodeus sericeus amarus, sunbleak Leucaspius delineatus, crucian carp Carassius carassius, common bleak Alburnus alburnus, dace Leuciscus leuciscus, chub L. cephalus, and tiger barb Puntigrus tetrazona. The taste sensitivity to certain substances has been estimated for these species. A comparative analysis has been performed considering the published data on other species of the family; as a result, a high specificity of the taste spectra of cyprinids is obtained. No obvious relationship of taste preferences with the fish lifestyle, their diet, and phylogenetic similarity has been revealed. All cyprinids keep food objects in their oral cavity the longer, the most is the food object palatability. The number of orosensory testing events performed with a food object differs in fish of different lifestyles and belonging to different trophic categories, but does not correlate with the taste properties of the food object. During orosensory testing, the first retention of the grasped object in the oral cavity is longer than subsequent ones. Retentions are many times longer if the object is finally swallowed than when the fish refuse to consume. The great similarity of behavior in cyprinids during orosensory testing of food indicates the conservatism of the feeding behavior compared to taste reception.

The first detection of DNA of Caryophyllaeus laticeps (Pallas, 1781) in sunbleak Leucaspius delineatus (Heckel, 1843)

Abstract. DNA of Caryophyllaeus laticeps (Pallas, 1781) (Cestoda: Caryophyllidea) was first found in the intestine of common sunbleak Leucaspius delineatus (Heckel, 1843) from the Irkutsk Reservoir. The aim of the study was to carry out a comparative analysis and reconstruction of the phylogenetic position of the parasite. Determination of the cox1 gene fragment and comparative analysis of the obtained and available in genetic databases nucleotide sequences showed high nucleotide diversity of C. laticeps both in the studied samples (0 6.4%) and in the reference sequences from the GenBank database (0 6.8%). The sequences of C. laticeps in the phylogenetic tree formed three clades containing local samples of sunbleak parasites in all of them. The most represented genotype (75%) is clustered with parasite sequences of the bream Abramis brama (Linnaeus, 1758) from Switzerland, Slovakia, and the European part of Russia. Another significant genotype (19%) is in the joint cluster with the C. laticeps sequences of the common carp Cyprinus carpio Linnaeus, 1758 (Italy). The need for additional studies on the biology and ecology of C. laticeps and revision of caryophyllid cestodes in fish in the Angara River and Lake Baikal were under consideration.

Critical thermal maxima of three small-bodied fish species (Cypriniformes) of different origin and protection status

Environmental changes related to global warming are both a threat to cold-water fishes and simultaneously create favourable conditions for the spread of eurythermic or warm-water species. In both cases, it is necessary to develop conservation strategies supported by precise ecological data, including thermal requirements. In this study, we determined the upper thermal tolerance thresholds and the critical maxima for three small, non-commercial Eurasian freshwater fish species; i.e. lake minnow Eupallasella (=Rhynchocypris) percnurus, sunbleak Leucaspius delineatus and topmouth gudgeon Pseudorasbora parva using the Critical Thermal Method at different acclimation temperatures, i.e. 18, 23, 28, and 33°C (highest treatment for topmouth gudgeon only). We hypothesized that lake minnow would have the lowest thermal tolerance and the topmouth gudgeon the highest. The response to temperature rise and the upper thermal limits were species-specific and correlated with the acclimation temperature, but not with fish length. Sunbleak showed the lowest thermal tolerance, though at 28°C both E. percnurus and L. delineatus reached a similar critical thermal limit. Topmouth gudgeon showed distinctly higher upper thresholds of thermal tolerance and at the highest acclimation temperature the critical upper limit for the species was close to 42°C. The results obtained for L. delineatus were surprising as we predicted that this leuciscid fish would be more tolerant of high temperatures than E. percnurus. We discuss the results in relation to the threat of extinction and the risk of species spreading beyond their natural range in the context of a warming environment.

Ichthyofauna of the Bilotserkivskyi lower reservoir on the Ros river

The composition of ichthyofauna of Ukraine is changing due to natural processes and the influence of anthropogenic factors in the internal water bodies. Systematic analysis of changes allows controlling these processes and maintaining the diversity of species at a constant level. The purpose of the study was to investigate changes in the composition of the ichthyofauna of the Bilotserkivskyi lower reservoir (Ros River) after the discharge of industrial waste of the Bilotserkivvoda enterprise in 2017 and 2020, which led to the mass death of fish and crayfish. The studies were conducted by catching fish with species identification and a survey of fishermen from November 2016 to October 2020. Additionally, the species composition of fish in this section of the Ros River was considered before the reservoir was created. According to the results of the conducted studies, 24 fish species were identified in 2016, 21 in 2017, and 19 in 2020. Analysing the number of ichthyofauna since the 1960s, it can be concluded that every 10 years the species composition of the ichthyofauna of the Bilotserkivskyi lower reservoir lost about 2-3 species of fish, which is conditioned by the influence of riverbed overlap, industrial activities, uncontrolled and unidentified discharges into the reservoir, etc. After a detailed analysis of the number of ichthyofauna, it was established that by 2016, the following species had disappeared: common dace Leuciscus leuciscus, Dnieper chub P. borysthenicus, ide I. idus, sunbleak Leucaspius delineatus, vimba bream Vimba vimba, crucian carp Carassius carassius, weatherfish Misgurnus fossilis, spined loach Cobitis taenia; in 2017 – species such as gudgeon Gobio gobio, round goby Neogobius melanostomus, tubenose goby Proterorhinus marmoratus; in 2020 – char, ruffe. Quantitative and qualitative restoration of ichthyofauna is possible at the expense of fish from the Protoka River (Rotok). To continue fishing use, it is necessary to settle fish in the reservoir. The practical significance of this study is to determine the species composition of the ichthyofauna for further use of the reservoir for environmental and fishery purposes

Comparative analysis and reconstruction of phylogenetic position of sunbleak Leucaspius delineatus (Heckel, 1843) from the Irkutsk Reservoir

Abstract. This work was aimed to a comparative analysis and reconstruction of the phylogenetic position of sunbleak Leucaspius delineatus (Heckel, 1843) from the Irkutsk Reservoir. Determination of a species specific fragment of the Cox1 gene allowed to reveal a unique common haplotype present in all specimens analyzed. Comparative analysis and phylogenetic reconstruction based on nucleotide sequences available in genetic databases showed that the studied species is represented by three phylogenetic lineages. Intraspecific differences of nucleotide sequences of fragments of the Cox1 gene amounted to 5.5%, and within phylogenetic lineages - < 3%. The studied fishes were related to the genetic lineage widely distributed in Europe and northwestern Russia. It is shown that all specimens with 100% genetic similarity belong to the same genotype, which is due to recent introduction of sunbleak into Pre-Baikal and to the founder effect .

Первые находки верховки Leucaspius delineatus (Cyprinidae) в бассейне оз. Байкал

Since the early 1960s, the sunbleak Leucaspius delineatus (Heckel, 1843), along with carp acclimatized from European Russia, regularly entered the siberian carp ponds, first in the Ob’ basin, and then in the Yenisei and Angara basins. In the last decade, we have discovered the sunbleak in two water bodies of the Baikal basin: in May 2013 - in the water intake and discharge canals of the Gusinoozersk regional power plant situated on the large lake Gusinoe in the Selenga River basin (Republic of Buryatia), and in November 2016, the sunbleak was registered in the diet of pike inhabiting the reservoirs of the Talaya-Pokhabikha lake-bog complex in the immediate vicinity of the Baikal coastline at the southern end of the lake in Irkutsk Region. The age series in the samples of the sunbleak in the water intake canal of the power plant was represented by five age groups from 1+ (SL 34.2 mm and 0.59 g of weight) to 5+ (SL 73.9 mm and 6.73 g, respectively) with a predominance of individuals aged 1+ and 2+. In the discharge canal only group 1+ (SL 35.5 mm and 0.69 g) was noted. The sex ratio in catches at the age of 1+ was 1:1.2 with a predominance of males; by the age of 3+, the proportion of males increased significantly (1:8.6). Sexual maturity of the sunbleak from Lake Gusinoe occurs at the age of 3+. Spawning is portioned, the first portion is layed down not earlier than the second half of July. The total fecundity of the seven studied females at the age of 3–5 + varies from 632 to 1539 eggs, averaging 1312 eggs. The sunbleaks from Lake Gusinoe are predominantly benthophagous. In the first half of May 2013, near the water intake canal, the main food components were the nymphs of the Corixidae water bugs and larvae of Phryganea caddis flies, planktonic crustaceans and imago of aerial insects were also consumed. In July 2014, in the discharge channel, the main food item was the chironomid larvae. In the lake Sludyanskoye, three specimens were identified from the stomachs of the pike living there. All fish were partially digested, and therefore it was not possible to analyse it.

Trophic consequences of an invasive, small-bodied non-native fish, sunbleak Leucaspius delineatus, for native pond fishes

Assessments of the trophic consequences of invasive fishes are important for quantifying their ecological impacts on native species more generally. A small-bodied cyprinid fish native to continental Europe and introduced in the 1970s to the U.K, the sunbleak Leuciscus delineatus, has been shown previously to establish closer social associations with native species of similar size than do native species amongst themselves. To assess the potential detrimental trophic consequences of native species associations with L. delineatus, a field-based experiment was undertaken in summer 2015 in six outdoor, artificial ponds containing three native cyprinid species (rudd Scardinius erthrophthalamus, gudgeon Gobio gobio, tench Tinca tinca). Three ponds were controls (no L. delineatus) and three were treatments (L. delineatus present). The results of stable isotope analysis (SIA) of fish tissue samples provided strong evidence that the isotopic niches of both native benthic fishes were reduced in the presence of L. delineatus, although there were no significant effects on the trophic position, body size or condition of two of the three native fish species. Introduced L. delineatus maintained a core isotopic niche that was distinct from the two native benthic fishes, with no overlap detected between native and non-native fishes when including 40% and 95% of the data. These results indicate that the response of the native fishes to the introduction of L. delineatus was niche constriction via trophic specialisation, with this response sufficient to maintain their growth rates and condition. This result is similar to studies on a range of small-bodied invasive fishes, suggesting the trophic impacts of these invaders are relatively consistent across species and systems.

Range expansion of rotan Perccottus glenii, sunbleak Leucaspius delineatus, and bleak Alburnus alburnus in the Ob River basin

The ranges of three alien fish species (rotan Perccottus glenii, sunbleak Leucaspius delineatus, and bleak Alburnus alburnus) in the Ob River basin, West Siberia, have expanded. Our data prove the expansion of rotan and sunbleak ranges to the north. In particular, for the first time, populations of rotan are reported from the lower section of the Ob. We also present new data about range expansion of the studied fish species southward. All three species have probably reached the southern limits of their possible distribution in the Upper Ob system, entering the potamon/rhithron transition zone, because the species under study prefer lowland waters. The spatio-temporal dynamics of their expansion reveals the role of the Ob River as the main invasion corridor, enhancing their distribution mostly in meridional direction. In the system of the Upper Ob, rotan and sunbleak were found by us in isolated ponds and lakes, as well as in floodplain systems. This is in agreement with the concept of two invasion vectors: the translocation of fish by humans between water bodies and self-distribution along the river courses.

Laboratory and field validation of a simple method for detecting four species of non-native freshwater fish using eDNA.

This paper presents the first phase in the development and validation of a simple and reliable environmental (e)DNA method using conventional PCR to detect four species of non-native freshwater fish: pumpkinseed Lepomis gibbosus, sunbleak Leucaspius delineatus, fathead minnow Pimephales promelas and topmouth gudgeon Pseudorasbora parva. The efficacy of the approach was demonstrated in indoor tank (44 l) trials in which all four species were detected within 24 h. Validation was through two field trials, in which L. gibbosus was detected 6-12 h after its introduction into outdoor experimental ponds and P. parva was successfully detected in disused fish rearing ponds where the species was known to exist. Thus, the filtration of small (30 ml) volumes of pond water was sufficient to capture fish eDNA and the approach emphasised the importance of taking multiple water samples of sufficient spatial coverage for detecting species of random or patchy distribution.

Distribution of alien fish species in lakes within the temperate climatic zone of Western Siberia

The composition of the fish community is studied in different lakes of the temperate climatic zone in Western Siberia. The patterns of the region’s occupation by different species in the aspect of geographical zoning are revealed. Only 7 of 19 species live within the limits of the whole region—pike Esox lucius, roach Rutilus rutilus, ide Leuciscus idus, lake minnow Phoxinus percnurus, tench Tinca tinca, crucian carp Carassius carassius, and perch Perca fluviatilis. The most stable species composition of fish is in the forest-swamp zone, where the population is formed by representatives of the aboriginal fauna. In lakes of the forest-steppe and steppe zones, six alien species, namely, sunbleak Leucaspius delineatus, bleak Alburnus alburnus, bream Abramis brama, Chinese goldfish Carassius auratus gibelio, wild carp Cyprinus carpio, and zander Sander lucioperca, have naturalized as a result of introduction. The establishment of Amur sleeper Perccottus glenii and Nikolskyi loach Misgurnus nikolskyi in water bodies of the forest-steppe zone occurs by self-spreading. At present, the share of alien species within the forest-steppe and steppe zones is 47 and 43% of fish species richness, respectively. The spatial distribution of alien species is directed from east to west within the forest-steppe zone. This is evidenced by the composition of self-spreading species whose natural range is the territory of the Far East.

Sphaerothecum destruens pathology in cyprinids

Sphaerothecum destruens is a significant intracellular parasite of fish which has caused disease and mortalities in cultured north American Chinook salmon Oncorhynchus tshawytscha and Atlantic salmon Salmo salar. Several hosts for S. destruens have been identified within the Salmonidae family, and the histopathology of the infection can differ between hosts. Recently, S. destruens has been associated with the most invasive cyprinid species in Europe, topmouth gudgeon Pseudorasbora parva. Accurate disease identification based on thorough descriptions of clinical signs and histopathology in this new range of hosts is thus paramount to support further epizootiological studies. In this study, the associated histopathology of S. destruens infection is described along with its pathogenesis in the endangered cyprinid sunbleak Leucaspius delineatus. Histological examination of 100 L. delineatus in a wild population in the south of England revealed the presence of S. destruens infections, with a prevalence of 5% with S. destruens, suggesting an over-dispersed distribution within the L. delineatus sample. Clinical signs of the infection were absent, but histological examination revealed the presence of both disseminated and nodular lesions in several organs.

Social network properties within a fish assemblage invaded by non-native sunbleak Leucaspius delineatus

Network theory is commonly used to reveal social interactions and the organisation of interconnected nodes—but has not yet been applied to animal invasions. Non-native species invasions are now considered one of the foremost threats to natural ecosystems and biodiversity. This is the first attempt to assess social network properties within a freshwater fish assemblage invaded by a non-native fish species. We show that invasive sunbleak Leucaspius delineatus is socially more strongly interconnected with native species than the native species with each other. The social networks also reveal characteristics of a ‘small world’ such as low clustering coefficients C and short path lengths L. The findings may indicate potential traits of successful invaders and the implication for the spread of pathogens between individuals within a group of animals that contain a non-native invasive species. The success of establishment and subsequent invasion may be highlighted not only by the capacity of the new species to adapt to the new environment, but also in its capacity to penetrate the social circle of the native community.

Recent releases and dispersal of non-native fishes in England and Wales, with emphasis on sunbleak Leucaspius delineatus (Heckel, 1843)

The introduced range of the European cyprinid, sunbleak Leucaspius delineatus, in England was previously limited to parts of southwest England but has now expanded across Southern England. Natural dispersal mechanisms cannot explain their increased distribution and fish stocking was not a factor. Thus, the accidental movement of either their eggs or larvae via anglers’ nets was believed to be the mechanism by which these fish were accidentally moved between waters over 100 km apart. This dispersal pathway is difficult to regulate, as is the release of unwanted non-native aquarium and pond fish into open waters by the public. This latter pathway has resulted in the recent releases of species including walking catfish Clarias batrachus, Asian weatherfish Misgurnus mizolepis and white catfish Ameiurus catus.

Fish movements: the introduction pathway for topmouth gudgeon Pseudorasbora parva and other non‐native fishes in the UK

Abstract The contamination of fish consignments (for stocking or aquaculture) is a major pathway by which non‐native organisms, including fish, are introduced to new areas. One of the best examples of this is the topmouth gudgeon Pseudorasbora parva, which was accidentally imported into Romania and then throughout Europe in consignments of Asian carp species. The introduction and spread of topmouth gudgeon in the UK has been linked to imports and movements of the ornamental variety (golden orfe) of ide Leuciscus idus. To examine this hypothesis, relationships between authorized movements of both native and non‐native fish species (in particular ide) and the occurrence in England of topmouth gudgeon were tested at the 10×10 km scale. Topmouth gudgeon occurrence in the wild was significantly correlated with the trajectories of movements of ornamental fish species (ide/orfe, sunbleak Leucaspius delineatus) as well as a few non‐ornamental fish species (European catfish Silurus glanis, Atlantic salmon Salmo salar and grass carp Ctenopharyngodon idella). These results highlight the mechanism by which non‐native fish species disperse from the point of first introduction, and especially that movements of fish within the country represent an important mechanism for accidental introductions of non‐native species. © Crown copyright 2010. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.

Do Eurasian otters Lutra lutra (L.) in the Somerset Levels prey preferentially on non-native fish species?

Eurasian otters Lutra lutra (L.) are known to be opportunistic, exploiting the most abundant prey available, however, there have been few studies of otter diet in lowland areas of Britain. The Somerset Levels and Moors, a coastal flood plain and marsh area of 64 000 ha in SW England, is an otter stronghold where a number of introduced, non-native fishes (common carp Cyprinus carpio, pumpkinseed Lepomis gibbosus, sunbleak Leucaspius delineatus) have been introduced, with the latter species occurring locally in high abundances. The present study aimed to determine whether otters of the Somerset Levels are preying on, and thus represent 'biological resistance' to, these non-native fishes. In 2004-2005, otter spraints (feces) were collected seasonally in areas of the Levels also subjected to fisheries surveys, and the data were used to determine diet composition and preferences. Otter diet was dominated by European eel Anguilla anguilla and threespine stickleback Gasterosteus aculeatus, and non-native species occurred relatively rarely (carp, sunbleak) or not at all (pumpkinseed) in the otter spraints. Seasonal variations in otter diet were observed, with birds notable for summer and sticklebacks for winter. Despite their relative prominence in the Somerset Levels, non-native fish species represented minor components of the otter's diet, a pattern also observed in Spain. In particular, the popular angling species (carp) was taken infrequently, but the species of high conservation interest (eel) was a preferred and common item in otter diet.

The role of pheromones in freshwater fishes

The study of fish pheromones is particularly relevant because of the conserved nature of chemoreception in vertebrates. However, most fish pheromone systems remain unstudied. All the major known pheromones of freshwater fish and their associated behaviours were reviewed. Importantly, those studies that have demonstrated the connection between behaviour and pheromones in freshwater fishes have resulted in a wide range of applications in management. For example, pheromones released by the sea lamprey Petromyzon marinus have a practical function in pheromone traps, showing how chemical communication can be used in the management of invasive species. Future research on fish pheromones should include olfactory systems in a wider range of species testing the possibility that a few distinct models could be applied to the all fishes. Progress in research on fish pheromones should include a closer collaboration with other research fields such as evolutionary biology to allow a better understanding of fish pheromones systems divergence and mate selection where correlation between phenotypic dominance and pheromone production is still largely ignored. Finally, the example of pheromone interaction between an invasive species topmouth gudgeon Pseudorasbora parva and a native endangered species sunbleak Leucaspius delineatus is provided to illustrate the concept of pheromone pollution that assists its establishment in a novel ecosystem.

The non‐indigenous freshwater fishes of Flanders (Belgium): review, status and trends over the last decade

Fourteen non‐indigenous fish species have been successfully introduced to the wild within the territory of Flanders; nine are considered naturalized. Most of the introductions occurred prior to 1950, with six species introduced since then. This paper reviews the available, hitherto scattered, information (including ‘grey literature’) on these 14 non‐indigenous fish species introductions, and evaluates a decade of data from fisheries surveys to assess the recent development of these non‐indigenous populations. Gibel carp Carassius gibelio and topmouth gudgeon Pseudorasbora parva are the most widespread of the non‐indigenous species in Flemish waters, and both continue to expand their ranges. A reduction in range has been observed in brown bullhead Ameiurus nebulosus only. A case is presented for not including European catfish Silurus glanis, sunbleak Leucaspius delineatus and European bullhead Cottus gobio on the list of non‐indigenous freshwater fishes in Flanders. Also discussed are non‐indigenous fish species that are likely to colonize Flanders inland waters in the near future.

Can sunbleak Leucaspius delineatus or topmouth gudgeon Pseudorasbora parva disperse through saline waters?

In order to determine the potential for the invasive fishes sunbleak Leucaspius delineatus and topmouth gudgeon Pseudorasbora parva to disperse through saline waters their behaviour and physiology were investigated during exposure to salinities of 10·0 and 12·5. Increased salinity caused an increase in whole body cortisol in both species, but sunbleak and topmouth gudgeon showed very different metabolic and behavioural responses to the salinity stress. Sunbleak displayed increased swimming activity in brackish water, which may be important for dispersal through saline waters in the wild, although there were increased metabolic costs associated with this behaviour. Conversely, topmouth gudgeon showed a reduction in both swimming activity and metabolic rate in brackish waters. A pronounced depression in food intake (70–80%) was shown by both species during the salinity exposures. Both sunbleak and topmouth gudgeon, however, showed a full recovery of food intake within 24 h following return to fresh water. Despite the fact that exposure to saline waters is stressful, and affects both physiology and behaviour, rapid recovery of appetite after return to fresh water suggests that short‐term use of brackish waters is a feasible dispersal route for sunbleak and topmouth gudgeon in the wild.

Is topmouth gudgeon Pseudorasbora parva responsible for the decline in sunbleak Leucaspius delineatus populations?

In England, a severe decline of introduced sunbleak Leucaspius delineatus populations has been attributed to the introduction of the invasive topmouth gudgeon Pseudorasbora parva. In France, however, after 4 years of P. parva colonization in a large natural lake, no demonstrated impacts on the native L. delineatus populations have been observed. This suggests that the original impacts observed in England, such as spawning inhibition and high mortality, were the result of an emerging pathogen, the rosette‐like agent, hosted by L. delineatus rather than P. parva.