The anadromous Rutilus kutum Kamenskii, 1901is the most important fish in north of Iran with the highest economic value. Ignoring the natural process of reproduction due artificial propagation, catching some migrating broodstocks from the sea (not from the estuaries) and mixing the produced fingerlings in culture ponds within restocking programs in the last 30 years have caused an uncertainty about homing success and population differentiation in the fish. A 13-landmark morphometric truss network system was used to investigate the hypothesis of homeward migration success and population differentiation, while the previous studies revealed low genetic variability among the fish populations. A total of 504 adult specimens were caught from four localities along the southern Caspian Sea in the reproductive period. Univariate analysis of variance showed significant differences among the four groups for 78 standardized morphometric measurements. In linear discriminant function analysis (DFA), the overall assignments of individuals into their original groups were 73.3 % and 80.3 % in males and females, respectively. The principal component analysis (PCA) and clustering analysis based on Euclidean square distances showed that the 504 examined specimens grouped into distinct areas. The results showed that each sampling site represents independent population which confirmed the success of homeward migration. The high grouping ranges suggests that almost all populations return to their birthplace river to breed, which results in high inbreeding. The results can be interesting for management and conservation programs of this valuable species in the Caspian Sea.
Analysis of the mitochondrial DNA (mtDNA) control region (CR) was used to examine the dispersal of females of a geometrid moth, Epirrita autumnata, in Fennoscandia. A 542-bp-portion of the CR of 200 individuals from four northern and four southern localities was sequenced. The mtDNA CR of E. autumnata contains a substantial amount of variation as a total of 108 mtDNA haplotypes were observed. Between the northern and the southern localities (~1100 km), there was a moderate level of genetic differentiation (FST = 0.128). The amount of variation in the mtDNA CR of E. autumnata was lower in the north than in the south. The reduction in genetic variability may result from a combination of historical bottlenecks that date back to the post-glacial recolonization of Fennoscandia and, present-day bottlenecks due to the northern E. autumnata populations experiencing repeated outbreaks followed by collapse in population size. On a small spatial scale (0.6-19 km), within the northern and southern areas, no genetic differentiation was detected suggesting ongoing gene flow due to the dispersal of E. autumnata females among the localities. This finding was contrary to our earlier expectation of poor flying ability of E. autumnata females.
Plebejus argus is a model species for studying the biology, population ecology and genetics of butterflies. It is patchily distributed throughout most of its European range and considered to be sedentary. Habitats of the butterfly have to encompass two vital larval-resources, i.e. specific food plants and ants, since caterpillars are obligatorily myrmecophilous. The genetic structure of nine P. argus populations (85 individuals) was studied at an intermediate geographical scale (Eastern Poland, diameter of about 400 km) using two kinds of molecular markers i.e. COI (mtDNA) and EF-1α (nuclear gene). Both markers were highly variable with as many as 16 haplotypes and 39 alleles, respectively. Great genetic differentiation in the COI gene was detected (overall FST = 0.411, P < 0.001) but little genetic differentiation in the EF-1α gene (FST = 0.021, P < 0.001). The number of COI haplotypes (ranging from one to seven) and their distribution varied considerably among P. argus populations. The possibility that this heterogeneity was related to Wolbachia was excluded as this endoparasitic bacterium was not detected in samples from any of the populations studied. PCA and SAMOVA analyses divided the sampled populations into two or three groups, which could indicate different colonization routes. Moreover, the differences in genetic differentiation with respect to mtDNA and nuclear markers may suggest male-biased dispersal of P. argus at a larger scale. The hypothesis that females are philopatric is consistent with direct observations of the restricted colonization abilities of the butterfly, while the relatively homogeneous genetic structure revealed by previous allozyme studies in some areas might be explained by the possible higher mobility of males. and Marcin Sielezniew, Donata Ponikwicka-Tyszko, Miroslaw Ratkiewicz, Izabela Dziekanska, Agata Kostro-Ambroziak, Robert Rutkowski.
Dry calcareous grasslands are among the most species-rich and endangered ecosystems in the Central- European landscape. They are of anthropogenic origin and mainly a result of grazing by domestic animals. Due to land-use changes in the last century, particularly in the 1960s, they were often abandoned or afforested. Therefore, in 1975 long-term experiments were started in the southwestern Germany (Baden-Württemberg) to determine the effectiveness of alternative management treatments in maintaining grasslands and their species composition. The aim of this study was to assess the effect of grazing (reference management treatment), mowing once a year, mulching twice a year, mulching every second year, burning once a year and succession (abandonment) on the population structure (in terms of density, age structure, reproduction mode) and seasonal germination niche of a dwarf shrub, Helianthemum nummularium, and a herbaceous plant, Lotus corniculatus. To study the age structure, annual ring analyses were applied. The classification of the reproduction mode, either by seed or vegetatively, was carried out by differentiating the central under-ground organ either as a root (in this case the individual has established from seed) or rhizome (the individual has developed from clonal multiplication). The seasonal germination niche was derived from the age structure. Management clearly affected population density and age structure. Highest density of individuals was found in the grazing and the lowest in the succession treatment. In the mulching every second year and succession treatments populations were senescent. Management also affected reproduction mode in H. nummularium. Regeneration by seed was especially enhanced by mowing and burning but was inhibited by mulching twice and succession. In the latter treatments H. nummularium reproduced only clonally. Helianthemum nummularium germinated mainly in autumn but burning by breaking the dormancy of seeds initiated germination in spring. A similar pattern was detected in L. corniculatus: burning increased germination rate in spring. Comparing population characters (density, age, reproduction mode) to the traditionally used grazing treatment, mowing was most similar and for L. corniculatus additionally burning. This is in contrast to the assessment of the vegetation of the management treatments where mowing and mulching twice per year maintain a similar floristic composition. Finally, the analysis of the population structure revealed important mechanisms behind population and vegetation dynamics.
The pollen beetle (Meligethes aeneus) is one of the most important insect pests of oilseed rape (Brassica napus), and extensive use of insecticides is required to protect crop yields. To meet the challenges set by agricultural demands for more sustainable production and changing climate more information about pest biology and population genetics is needed. Using genomic Amplified Fragment Length Polymorphism (AFLP) analysis, DNA polymorphism was studied in 14 field populations of pollen beetles, collected during 2004 in six European countries (Denmark, France, Finland, Germany, Sweden, and UK). Using one primer combination 410 polymorphic DNA fragments were obtained based on analysis of single beetles. AFLP profiles were analysed with similarity measures using the Nei and Li coefficient and dendrograms generated. Dendrograms constructed from distance matrices revealed clustering by population origin and assignment analysis generally supported the genotype classification. Principal component analysis of the fourteen groups resulted in wide dispersion but also connections between some groups. Statistical analysis using AMOVA showed that the levels of genetic variation within populations explained most of the variation. Migrant analysis suggested a low level of gene flow between pollen beetle populations at different geographical locations indicating little long range dispersal of pollen beetles. However, a Mantel test found no correlation between genetic and geographical distance. Apparently genetic differentiation among populations has a complex background and may involve factors such as local adaptation and founder effects.
Brazilian native meliponines are currently threatened by increased human impacts. The assessment of their genetic variation by microsatellite DNA markers can assist in the conservation of populations and help in the planning and establishment of efficient management strategies. The purpose of this study was to develop the first set of microsatellite markers for Melipona fasciculata, selected from partial genome assembly of Illumina paired-end reads. Primer pairs were designed for each detected locus at their flanking regions. Bee samples were genotyped from two different populations of Northeastern Brazil for marker characterization and validation. A total of 17 microsatellite loci displayed polymorphism. Mean HE and HO heterozygosities were 0.453 and 0.536, respectively. PIC across all loci ranged from 0.108 to 0.714. A genetic diversity analysis revealed high values for population differentiation estimates (FST = 0.194, RST = 0.230, and Dest = 0.162) within the investigated region. PCoA and Bayesian clustering showed a separation of the species into two distinct clusters. These microsatellite markers have demonstrated strong potential for population-level genetic studies. Moreover, the preliminary analysis of the genetic diversity in M. fasciculata provides provisional evidence of significant population differentiation between the two studied populations., Geice Ribeiro Da Silva, Isis Gomes De Brito Souza, Fabia De Mello Pereira, Bruno De Almeida Souza, Maria Teresa Do Rego Lopes, Paul Bentzen, Fabio Mendonça Diniz., and Obsahuje bibliografii
Climate change scenarios predict losses of cold-adapted species from insular locations, such as middle high mountains at temperate latitudes, where alpine habitats extend for a few hundred meters above the timberline. However, there are very few studies following the fates of such species in the currently warming climate. We compared transect monitoring data on an alpine butterfly, Erebia epiphron (Nymphalidae: Satyrinae) from summit elevations of two such alpine islands (above 1300 m) in the Jeseník Mts and Krkonoše Mts, Czech Republic. We asked if population density, relative total population abundance and phenology recorded in the late 1990s (past) differs that recorded early in 2010s (present) and if the patterns are consistent in the two areas, which are separated by 150 km. We found that butterfly numbers recorded per transect walk decreased between the past and the present, but relative population abundances remained unchanged. This contradictory observation is due to an extension in the adult flight period, which currently begins ca 10 days earlier and lasts for longer, resulting in the same total abundances with less prominent peaks in abundance. We interpret this development as desynchronization of annual cohort development, which might be caused by milder winters with less predictable snow cover and more variable timing of larval diapause termination. Although both the Jeseník and Krkonoše populations of E. epiphron are abundant enough to withstand such desynchronization, decreased synchronicity of annual cohort development may be detrimental for innumerable small populations of relic species in mountains across the globe., Martin Konvička, Jiří Beneš, Oldřich Čížek, Tomáš Kuras, Irena Klečková., and Obsahuje bibliografii
We studied the demography and spatial structure of the muskrat population at the Nizhnekamsk Reservoir in central Russia. 45Ca radioactive prenatal labelling of muskrats was performed over a period of eight years. A total of 3,876 infividual muskrats were captured from a 12 km2 experimental plot and analysed on the basis of age, sex and presence of radioactivity. During the first year of life, the highest mortality was among muskrats from the latest litter, whilst during the second year of life it was amongst individuals from the earlier litters. Spring and autumn muskrat migration were studied and we observed a cyclical type of spatial structuring within the population. The proportion of individuals migrating in autumn varied from 18-57%, but significant differences in the migratory activities of different age groups were not observed. We found several tendencies throughout the eight years: a decrease in the proportion of the first litter (not overwintering), an increase in the proportion of third litters, and a decrease in the proportion of yearlings born in the first litter - we assume these represent responses to flooding.
Life-history parameters of Barbus peloponnesius and Barbus cyclolepis were studied in two streams in Macedonia, Greece. In B. peloponnesius age ranged from 0+ to 4+ in males and 0+ to 9+ in females, while in B. cyclolepis from 0+ to 5+ in males and 0+ to 9+ in females. In both species, after the first year of life, females exhibited longer mean lengths at age and greater maximum length than the males, while between species B. cyclolepis showed greater mean lengths at age and greater maximum length than B. peloponnesius. Total mortality rates were higher in the males of each species than in females. Significant difference in the sex ratio was found only for B. cyclolepis and this species population was male dominated. Gonad maturation began at the age of 1+ in males and 3+ in females of both species. Both species exhibited a protracted multi-spawning season, which started at the end of March-beginning of April and lasted until mid July. Despite differences in growth and body size, the two species are characterized by similar life-history styles: (1) similar age structure, (2) early maturation and same age at maturity, (3) males have a shorter life span, higher rate of mortality, decreased growth and smaller body size and mature earlier than the females and (4) elongated multi-spawning season, which shows a high investment in reproduction. The life-history style of the two stocks seems to be in concordance with the environmental conditions of their habitats, which are typical of the fluctuating Mediterranean streams.
The short-finned eel Anguilla bicolor is known to be subdivided in two distinct subspecies (i.e. A. bicolor bicolor and A. bicolor pacifica), each subspecies being geographically distributed in allopatry. The present survey intends to describe genetic differentiation, population structure, molecular variance and phylogeny of both subspecies of A. bicolor in Indonesian waters. The genotypes of seven microsatellite locus and sequences of the entire cytochrome b were analyzed on 180 specimens collected in 10 representative locations, where one of the two subspecies spend their freshwater life. The results showed high heterozygosity (0.767 < He < 0.891). Significant deviation from Hardy-Weinberg equilibrium were essentially detected on AjTR04 and Aro63 loci. No diagnostic microsatellite loci was observed between the subspecies which shared most of their alleles. Genetic Reynolds distances computed for each population ranged
between 0.029 and 0.073 among A. bicolor pacifica populations, between 0.045 and 0.149 among A. bicolor bicolor populations and between 0.042 and 0.114 among populations of different subspecies. Both the mitochondrial and the microsatellite markers confirm the subdivision into two subspecies while microsatellite loci suggest a moderate differentiation between subspecies.