In this study, the effects of the eye fluke Diplostomum pseudospathaceum (Trematoda) infection on over-winter survival of young-of-the-year (YOY) European bitterling Rhodeus amarus (Cyprinidae) were examined between September 2010 and April 2011. The fish were reared in semi-natural conditions to ensure that results were not confounded by other parasite infections. The cumulative mortality of R. amarus from November until April was significantly higher in D. pseudospathaceum-infected fish (57·3%) compared to controls (42·1%). Infection of the parental generation did not have any effect on the mortality of juveniles. The results indicate that D. pseudospathaceum infection increases over-winter mortality of YOY R. amarus. The possible mechanisms causing mortality are discussed.

• Klíčová slova
• Diplostomum pseudospathaceum, Trematoda, bitterling, metacercariae, parasite infection,
• MeSH
• Cyprinidae parazitologie   MeSH
• nemoci ryb mortalita   parazitologie   MeSH
• roční období MeSH
• Trematoda * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The seasonal dynamics of biological traits in a population of European bitterling Rhodeus amarus from a small river in central Europe (River Kyjovka, Czech Republic) were investigated from April 2007 to March 2008. The reproductive season lasted from early April to mid-June, with a peak in late April when > 50% of females possessed ripe eggs in their ovaries. The sex ratio was female-biased, with a higher bias following the peak in reproduction, suggesting higher mortality of males than females over the reproductive period. The population was effectively annual, with a major decrease in adult fish abundance at the end of the reproductive period. Highest relative lipid content and condition factor were observed in February, both decreasing with an increase in investment into gonads. Seasonal dynamics in somatic condition, relative lipid content and gonad mass, and their comparison with other R. amarus populations, suggest that the study population allocated a disproportionally high level of resources to reproduction.

• MeSH
• Cyprinidae fyziologie   MeSH
• lipidy analýza   MeSH
• ovarium fyziologie   MeSH
• poměr pohlaví MeSH
• populační dynamika MeSH
• řeky MeSH
• roční období * MeSH
• rozmnožování MeSH
• velikost těla MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• lipidy MeSH

A 15 year data set revealed that the abundance of 0+ year Rhodeus amarus in a regulated river was negatively associated with mean river discharge, while mean standard length was positively related to the cumulative number of degree-days > or =10 degrees C. Results are discussed in the context of the recent invasion success of R. amarus.

• MeSH
• biologické modely MeSH
• Cyprinidae růst a vývoj   fyziologie   MeSH
• pohyb vody * MeSH
• regresní analýza MeSH
• řeky MeSH
• teplota MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

Coevolutionary relationships between parasites and hosts can elevate the rate of evolutionary changes owing to reciprocal adaptations between coevolving partners. Such relationships can result in the evolution of host specificity. Recent methodological advances have permitted the recognition of cryptic lineages, with important consequences for our understanding of biological diversity. We used the European bitterling (Rhodeus amarus), a freshwater fish that parasitizes unionid mussels, to investigate host specialization across regions of recent and ancient sympatry between coevolving partners. We combined genetic data (12 microsatellite and 2 mitochondrial markers) from five populations with experimental data for possible mechanisms of host species recognition (imprinting and conditioning). We found no strong evidence for the existence of cryptic lineages in R. amarus, though a small proportion of variation among individuals in an area of recent bitterling-mussel association was statistically significant in explaining host specificity. No other measures supported the existence of host-specific lineages. Behavioural data revealed a weak effect of conditioning that biased behavioural preferences towards specific host species. Host imprinting had no effect on oviposition behaviour. Overall, we established that populations of R. amarus show limited potential for specialization, manifested as weak effects of host conditioning and genetic within-population structure. Rhodeus amarus is the only species of mussel-parasitizing fish in Europe, which contrasts with the species-rich communities of bitterling in eastern Asia where several host-specific bitterling occur. We discuss costs and constraints on the evolution of host-specific lineages in our study system and more generally.

• MeSH
• biologická evoluce MeSH
• Cyprinidae genetika   parazitologie   MeSH
• databáze genetické MeSH
• genetická variace MeSH
• genetické markery MeSH
• haplotypy MeSH
• hostitelská specificita * MeSH
• interakce hostitele a parazita * MeSH
• kladení vajíček genetika   MeSH
• mikrosatelitní repetice MeSH
• mlži genetika   patogenita   MeSH
• paraziti MeSH
• sladká voda MeSH
• symbióza * MeSH
• sympatrie MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Dálný východ MeSH
• Evropa MeSH
• Názvy látek
• genetické markery MeSH

Parasite community composition of European bitterling (Rhodeus amarus), the only bitterling species occurring on the European continent, was investigated in 16 different localities from four European sea drainages during 1998-2007. A total of 41 species of metazoan parasites was identified. Nine parasite species are new records for European bitterling, namely Dactylogyrus rarissimus, D. suecicus, D. yinwenyingae, Gyrodactylus vimbi, Sphaerostomum globiporum, Petasiger sp., Paryphostomum radiatum, Ichthyocotylurus variegatus and Posthodiplostomum brevicaudatum. The specialist Gyrodactylus rhodei was the most widely distributed and one of the most prevalent species. The most frequent digenean species, represented by larval stages, was Metorchis xanthosomus. The parasite community of European bitterling was characterised by the dominance of generalists and parasites with autogenic life cycles. The rare occurrence of strictly endoparasitic species reflected the specific diet of the fish host. The character of the habitat significantly affected the parasite assemblages of bitterling. The greatest similarity was associated with lentic habitats (gravel pits and oxbows) and the lowest similarity between gravel pits and rivers. Juvenile bitterling from 8mm in length upwards were colonised by metazoan parasites, firstly by the monogenean G. rhodei. Host body size was positively correlated with parasite species richness, but the variability explained by length was low.

• MeSH
• Cyprinidae parazitologie   MeSH
• ekosystém * MeSH
• interakce hostitele a parazita * MeSH
• nemoci ryb parazitologie   MeSH
• parazitární nemoci u zvířat parazitologie   MeSH
• paraziti klasifikace   izolace a purifikace   fyziologie   MeSH
• velikost těla MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Evropa MeSH

Body condition and parasite abundance were examined in two size classes of European bitterling Rhodeus amarus during the first overwintering period in two seasons (2007-2008 and 2009-2010). Body condition of large fish did not change during winter, and increased significantly in March. From November to February, small fish showed a decreasing trend in condition. Despite a significant increase in March condition of small fish only reached the same level as before winter. Total parasite abundance increased significantly in winter in both fish size classes, reflecting a seasonal increase in monogenean infection. Large fish were parasitized significantly more than small fish during winter, but only in small fish was a negative correlation between parasite infection and condition found and a significant decrease in parasite abundance recorded after wintering, indicating mortality of heavily infected individuals with low condition during the winter. A trend for higher overwinter mortality in small fish was found under semi-experimental conditions. The decrease in condition during the winter period in small fish may reflect faster energy depletion generally expected in smaller individuals. The results indicate that parasite infection may contribute to the overwinter mortality of 0+ year R. amarus, with a stronger effect in smaller individuals.

• MeSH
• analýza přežití MeSH
• Cyprinidae MeSH
• hustota populace MeSH
• infekce červy třídy Trematoda mortalita   patologie   MeSH
• interakce hostitele a parazita MeSH
• nemoci ryb mortalita   patologie   MeSH
• roční období * MeSH
• tělesná konstituce fyziologie   MeSH
• Trematoda fyziologie   MeSH
• velikost těla fyziologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

An understanding of recent evolutionary processes is essential for the successful conservation and management of contemporary populations, especially where they concern the introduction or invasion of species outside their natural range. However, the potentially negative implications of intraspecific introductions and invasions have attracted less attention, although they also represent a potential threat to biodiversity, and are commonly facilitated through human activities. The European bitterling (Rhodeus amarus) is a small cyprinid fish that decreased greatly in its distribution during the 1970s and 1980s and was subsequently included on many European conservation lists. This decline appears to have reversed, and the extent of its distribution now exceeds its former range. We used a combination of 12 microsatellite markers and cytochrome b sequences on a large data set (693 individuals) across the current range of the European bitterling to investigate possible scenarios for its colonization of Europe. We show that the inferred history of colonization of Europe was largely congruent between mitochondrial and nuclear markers. The most divergent mtDNA lineages occur in the Aegean region but probably are not reproductively isolated as the Aegean populations also displayed mtDNA haplotypes from other lineages and nuclear data indicated their close relationship to Danubian populations. Much of Europe is currently populated by descendants of two main lineages that came to natural secondary contact in western Europe. An approximate Bayesian computation analysis indicates different dates for admixture events among western and central European populations ranging from the last deglaciation (natural) to the last few centuries (human-assisted translocations).

• MeSH
• Bayesova věta MeSH
• Cyprinidae genetika   MeSH
• fylogeografie MeSH
• genetická variace * MeSH
• genotyp MeSH
• mikrosatelitní repetice MeSH
• mitochondriální DNA genetika   MeSH
• modely genetické MeSH
• molekulární evoluce * MeSH
• populační genetika * MeSH
• sekvenční analýza DNA MeSH
• zeměpis MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Evropa MeSH
• Názvy látek
• mitochondriální DNA MeSH

The spatial distribution of breeding resources can have pronounced demographic and evolutionary consequences. We used 20 experimental groups of the bitterling (Rhodeus amarus), an annual fish with a promiscuous, resource-based mating system, and extended breeding season to investigate how the spatial distribution (clumped or regular) of bitterling oviposition sites (live freshwater mussels) affected offspring production, variation in reproductive success, and directional selection on phenotypic traits over their entire reproductive lifetime. We did not detect any effect of resource distribution on offspring production or variation in reproductive success among individual fish, although variation between replicates was higher with a clumped distribution. This finding is discussed with regard to the incidence of alternative mating behaviors (sneaking) within the limitations imposed by our experimental design. Breeding resource distribution had a significant effect on selection on male phenotypic traits. Stronger directional selection on traits associated with intrasexual competition for fertilizations, gonad mass (an indicator of sperm competition), and the extent of red, carotenoid-based pigment in the iris (an index of dominance status), was detected with a clumped resource distribution. With a regular resource distribution, a stronger positive selection on male body size was detected. We discuss the implications of our results for natural populations.

• MeSH
• kladení vajíček MeSH
• rozmnožování MeSH
• ryby fyziologie   MeSH
• sexuální chování zvířat MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

We present the phylogenetic relationships of the freshwater fish genus Rhodeus from 45 localities in Europe and three localities in the Amur basin using the mitochondrial cytochrome b sequence. The study aims to (1) test the colonisation history between Europe and East Asia and (2) to reconstruct the evolutionary history of Rhodeus in Europe. Our analyses revealed five monophyletic clades which correspond to four species: R. sericeus in the Amur basin, R. meridionalis in the River Vardar, R. colchicus in western Caucasus and two sister lineages in most of Europe which together represent R. amarus. The reconstructed colonisation scenario assumes a continuous distribution of Rhodeus from Europe through Siberia until East Asia during Pliocene, depletion of the Siberian population in late Pliocene, isolation of the population in River Vardar during early Pleistocene, refuges during late Pleistocene glaciations in the Danubian basin, in the lowlands of western Black Sea and in western Caucasus Mountains and a post-glacial expansion from the Danubian refuge towards western Europe and from the Black Sea refuge across Eastern Europe.

• MeSH
• Cyprinidae klasifikace   genetika   MeSH
• fylogeneze * MeSH
• mitochondriální DNA analýza   MeSH
• řeky * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Geografické názvy
• Evropa MeSH
• Sibiř MeSH
• Názvy látek
• mitochondriální DNA MeSH

The aim of this study was to evaluate the influence of preservation method on the results of parasite community studies. Two host species, European perch Perca fluviatilis and European bitterling Rhodeus amarus, were examined for parasites after having been subjected to 4 different storage treatments: freezing, preservation in 4% formaldehyde or 70% ethanol and transportation of live (fresh) fish as a control. Preservation prior to dissection resulted in a loss of information, leading to incomplete quantitative data (all preservation treatments), qualitative data (ethanol and formaldehyde preservation) and a lowered ability to determine parasites to species level based on morphology compared to dissecting fresh fish. Of the more abundant taxa, only crustaceans and acanthocephalans provided relatively even results between treatments. We conclude that preservation media, such as ethanol or formaldehyde, significantly affects the ability to obtain precise parasite community data; hence, we recommend the use of freshly sacrificed fish for parasite community studies whenever possible. Alternatively, freezing may prove acceptable for evaluating parasite community taxonomic composition.

• Klíčová slova
• Parasite community, Parasitological examination, Perca fluviatilis, Preservation methods, Rhodeus amarus ·∙ Methodology,
• MeSH
• Cyprinidae parazitologie   MeSH
• ethanol MeSH
• formaldehyd MeSH
• nemoci ryb parazitologie   MeSH
• odběr biologického vzorku metody   veterinární   MeSH
• paraziti klasifikace   izolace a purifikace   MeSH
• Perciformes parazitologie   MeSH
• uchovávání tkání metody   MeSH
• zmrazování MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ethanol MeSH
• formaldehyd MeSH