Geographic variations in life-history characteristics of white-spotted charr (Salvelinus leucomaenis)

1999 ◽  
Vol 77 (6) ◽  
pp. 871-878 ◽  
Author(s):  
Shoichiro Yamamoto ◽  
Kentaro Morita ◽  
Akira Goto
Keyword(s):  
Population Structure ◽  
Breeding Population ◽  
Relative Difference ◽  
Population Variation ◽  
Geographic Variations ◽  
River Population ◽  
Salvelinus Leucomaenis ◽  
Breeding Populations ◽  
Mature Parr ◽  
Three Rivers

Breeding-population structure, age and size at maturity, age and size at smolting, and riverine growth rate were investigated for three populations of white-spotted charr (Salvelinus leucomaenis) in the Nairo, Haraki, and Takahara rivers in Japan. The breeding populations in the Nairo and Haraki rivers on Hokkaido Island exhibited size polymorphism, comprising smaller mature parr and larger migrants. On the other hand, the population in the Takahara River on central Honshu Island showed a monomorphic structure, being composed of mature parr only. Maturation at the parr stage was positively associated with body size. The patterns of length-specific maturation ratios in the three rivers were similar, although females matured at a larger size than males. Smolt sizes differed between the polymorphic populations in the Nairo and Haraki rivers, but size relationships between the sexes were similar in the two populations. The incidence of smolts of a given length within populations was much higher in the northern Nairo River population than in the more southerly Haraki River population. These observations indicate that among-population variation in the structure of white-spotted charr populations might be related to differences in the relative proportions of mature parr and smolts in the population. We suggest that the relative difference in size thresholds between smolting and maturation determines the relative incidence of mature parr and smolts, both within and among populations and between the sexes, which in turn regulates the breeding-population structure.

scholarly journals A survey of recent introduction events, spread and mitigation efforts of mynas (Acridotheres sp.) in Spain and Portugal

2015 ◽  
Vol 38 (1) ◽  
pp. 121-127
Author(s):  
S. Saavedra ◽  
◽  
A. Maraver ◽  
J. D. Anadón ◽  
J. L. Tella ◽  
...  
Keyword(s):  
Field Survey ◽  
Invasive Alien Species ◽  
Breeding Population ◽  
Island Populations ◽  
Common Myna ◽  
Breeding Populations ◽  
Preventive Actions ◽  
Acridotheres Tristis ◽  
The Common ◽  
Exponential Population Growth

The common myna Acridotheres tristis is listed among the world’s 100 worst invasive alien species. We combined previous records with a field survey to update the extent and fate of myna introductions in Spain and Portugal. Results suggest that there have been at least 22 independent accidental introductions of three myna species throughout the Iberian peninsula and three archipelagos since the early 1990s. While bank mynas (A. ginginianus) did not become established elsewhere, common mynas reached breeding populations on four islands. Eradication efforts allowed the extirpation of these breeding island populations, but common mynas continue to breed in the Tagus Estuary (continental Portugal). In this region, there is also a breeding population of crested mynas (A. cristatellus), which was undergone an exponential population growth in the last decade. To avoid further accidental introductions, eradication campaigns should be combined with preventive actions aiming to stop the trade of these species in Europe.

scholarly journals Chinese Fir Breeding in the High-Throughput Sequencing Era: Insights from SNPs

Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 681 ◽  
Author(s):  
Huiquan Zheng ◽  
Dehuo Hu ◽  
Ruping Wei ◽  
Shu Yan ◽  
Runhui Wang
Keyword(s):  
Population Structure ◽  
Genetic Structure ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
Breeding Population ◽  
Population Diversity ◽  
Chinese Fir ◽  
High Density ◽  
Population Structure Analysis ◽  
Snp Panel

Knowledge on population diversity and structure is of fundamental importance for conifer breeding programs. In this study, we concentrated on the development and application of high-density single nucleotide polymorphism (SNP) markers through a high-throughput sequencing technique termed as specific-locus amplified fragment sequencing (SLAF-seq) for the economically important conifer tree species, Chinese fir (Cunninghamia lanceolata). Based on the SLAF-seq, we successfully established a high-density SNP panel consisting of 108,753 genomic SNPs from Chinese fir. This SNP panel facilitated us in gaining insight into the genetic base of the Chinese fir advance breeding population with 221 genotypes for its genetic variation, relationship and diversity, and population structure status. Overall, the present population appears to have considerable genetic variability. Most (94.15%) of the variability was attributed to the genetic differentiation of genotypes, very limited (5.85%) variation occurred on the population (sub-origin set) level. Correspondingly, low FST (0.0285–0.0990) values were seen for the sub-origin sets. When viewing the genetic structure of the population regardless of its sub-origin set feature, the present SNP data opened a new population picture where the advanced Chinese fir breeding population could be divided into four genetic sets, as evidenced by phylogenetic tree and population structure analysis results, albeit some difference in membership of the corresponding set (cluster vs. group). It also suggested that all the genetic sets were admixed clades revealing a complex relationship of the genotypes of this population. With a step wise pruning procedure, we captured a core collection (core 0.650) harboring 143 genotypes that maintains all the allele, diversity, and specific genetic structure of the whole population. This generalist core is valuable for the Chinese fir advanced breeding program and further genetic/genomic studies.

The Loggerhead Turtle, Caretta-Caretta, in Queensland - Population Breeding Structure

1988 ◽  
Vol 15 (2) ◽  
pp. 197 ◽  
Author(s):  
E Gyuris ◽  
CJ Limpus
Keyword(s):  
Genetic Variation ◽  
Life History ◽  
Loggerhead Turtle ◽  
Caretta Caretta ◽  
Breeding Population ◽  
Barrier Reef ◽  
Breeding Structure ◽  
Marine Park ◽  
Breeding Populations ◽  
Population Breeding

Population models proposed as a result of independent tagging programs of nesting Caretta caretta in Queensland are in disagreement about the size of discrete breeding units. An electrophoretic survey was conducted to assess the relevance of genetic variation as revealed by electrophoresis to the investigation of Caretta caretta population breeding structure. Low level electrophoretic variability (H*L(obs) = 0.016) was found. The geographical distribution of alleles, when compared with tag-recapture data and other aspects of life history, indicated that discrete breeding populations of C. caretta in Queensland are larger than previously thought. C. caretta nesting on the mainland beaches and on the cays of the Capricornia Section of the Great Barrier Reef Marine Park form a panmictic population. The data indicate that those nesting on the Swain Reefs cays do not interbreed with the mainland-Capricornia breeding population.

Haemoparasites of the pied flycatcher: inter-population variation in the prevalence and community composition

Parasitology ◽  
2017 ◽  
Vol 145 (7) ◽  
pp. 912-919 ◽  
Author(s):  
Anna Dubiec ◽  
Edyta Podmokła ◽  
Iga Harnist ◽  
Tomasz D. Mazgajski
Keyword(s):  
Community Composition ◽  
Population Variation ◽  
Pied Flycatcher ◽  
Blood Parasites ◽  
Avian Host ◽  
Long Distance ◽  
Breeding Populations ◽  
Host Sex ◽  
Study Population ◽  
Host Life

AbstractThe prevalence and community composition of haemoparasites can substantially differ among avian host populations, which may lead to different selection pressures. Therefore, information about these parameters is crucial for understanding, e.g. the inter-population variation in host life history traits. Here, we molecularly screened a population of a long-distance migrant, the pied flycatcher Ficedula hypoleuca, from central Poland for the presence of three genera of blood parasites: Haemoproteus, Plasmodium and Trypanosoma. The infection rate in this population was the highest for haemosporidians (86·8%) and one of the highest for trypanosomes (39·7%) among the thus far screened breeding populations of this species. The haemosporidian community was composed of six Haemoproteus/Plasmodium lineages, and the trypanosome community – 4 species and a parasite assigned to genus level. Trypanosomes were dominated by T. culicavium, a recently described species, corroborating the prediction that insectivorous songbirds are vertebrate hosts of this parasite. Host sex and age did not explain variation in infection incidence except for the higher trypanosome infection rates in males. A comparison of the study population with three other breeding populations previously screened molecularly for haemosporidians showed some geographic differences. This study confirms the importance of examining local parasite communities across a host distribution range.

Isonymy and population structure of Irish isolates during the 1890s

1982 ◽  
Vol 14 (2) ◽  
pp. 241-247 ◽  
Author(s):  
John H. Relethford
Keyword(s):  
Population Structure ◽  
Genetic Variation ◽  
Isolation By Distance ◽  
Breeding Population ◽  
Isolated Populations ◽  
Estimated Parameters ◽  
Distance Model ◽  
Local Breeding ◽  
And Migration ◽  
Close Fit

SummaryThe estimation of genetic similarity from correspondence of surnames (isonymy) allows investigation of historical population structure. This study uses surname data from seven isolates located along the west coast of Ireland during the 1890s to assess geographic and historic influences on population structure. Observed genetic variation among populations shows a close fit with the expected isolation by distance model, with estimated parameters of isolation and migration being similar to those obtained in other studies of isolated populations. Local genetic variation appears to be due primarily to the size of the local breeding population, with deviations being explained in terms of recent emigration.

Population structure of the Sahiwal breed in Pakistan

1995 ◽  
Vol 60 (2) ◽  
pp. 163-168 ◽  
Author(s):  
A. Dahlin ◽  
U. N. Khan ◽  
A. H. Zafar ◽  
M. Saleem ◽  
M. A. Chaudhry ◽  
...  
Keyword(s):  
Population Structure ◽  
Population Size ◽  
Effective Population Size ◽  
Breeding Population ◽  
Effective Population ◽  
Data Set ◽  
Inbreeding Coefficients ◽  
Sahiwal Cows ◽  
The Mean ◽  
Average Population Size

AbstractThe present study was undertaken to assist conservation and improvement schemes in the Sahiwal breed of cattle in Pakistan. A data set, consisting of records of 244 pure Sahiwal breeding bulls and 5247 cows, the latter representing about 80% of all recorded Sahiwal cows in Pakistan born during a period covering about 20 years, was analysed with regard to inbreeding, additive relationships, effective population size and generation intervals. Average inbreeding coefficients of 1224 cows and 49 bulls, for which at least the grandparents and great-grandsires were known, were 0·043 and 0·046, respectively. About two-thirds of the inbreeding was due to matings between animals with parents or grandparents in common. The mean additive relationship among the cows was 0·062, with within-herd averages ranging from 0·087 to 0·358. The average population size in a subdata set of recorded Sahiwal cattle from 1980 to 1984 was 1612, whereas the most likely estimate of the effective population size was about 30 animals for the same active breeding population. The study indicated the immediate need for an active conservation programme whereby the Sahiwal subpopulations of India and Kenya also should be involved.

Excess allozyme homozygosity and breeding population structure in the Mussel Mytilus californianus

1975 ◽  
Vol 32 (3) ◽  
pp. 303-311 ◽  
Author(s):  
M. L. Tracey ◽  
N. F. Bellet ◽  
C. D. Gravem
Keyword(s):  
Population Structure ◽  
Breeding Population ◽  
Mytilus Californianus

Contrasting population genetic structure of two widespread aquatic insects in the Chilean high-slope rivers

2011 ◽  
Vol 62 (1) ◽  
pp. 1 ◽  
Author(s):  
M. C. Sabando ◽  
I. Vila ◽  
R. Peñaloza ◽  
D. Véliz
Keyword(s):  
Population Structure ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Aquatic Insects ◽  
Population Genetic ◽  
Nuclear Markers ◽  
Widespread Species ◽  
Central Chile ◽  
Physical Barriers ◽  
Three Rivers

Dispersal and many other factors affect population genetic structure. In central Chile, rivers are characterised by strong currents and transverse mountain chains, which impose physical barriers to the populations that inhabit them. The objective of the present study was to study the population genetic structure of two widespread species of aquatic insects, the caddisfly Smicridea annulicornis and the mayfly Andesiops torrens, in three isolated rivers, Choapa, Maipo and Maule. The analysis of population structure, using both mtDNA (cytochrome C oxidase subunit 1, COI) and nuclear markers (amplified fragment length polymorphism, AFLP), considered samples from within and among rivers. In S. annulicornis, we found differentiation within and among rivers, indicating a low dispersal among the study area. Populations of A. torrens shared haplotypes in all three rivers and no differences were found among rivers, indicating that this species probably has more dispersal potential than does S. annulicornis; however, significant differences were observed within rivers. Our results indicate that the transverse mountain chains are not a barrier for A. torrens, which can disperse among rivers. Within rivers, the population structure suggests that these species are probably adapted to avoid drift because of the torrential character of these Chilean rivers.

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