Allozyme data reveal genetic diversity and isolation by distance in sympatric Glyphidrilus Horst, 1889 (Oligochaeta: Almidae) of the Lower Mekong River Basin

The genus Glyphidrilus, comprised of semi-aquatic freshwater earthworms that live in an ecotone between terrestrial and freshwater ecosystems, are widely distributed along riverbanks and rice paddy systems. Two Glyphidrilus species (Glyphidrilus vangviengensis and Glyphidrilus mekongensis) are endemic in the Lower Mekong River Basin and are sympatric from Northern Thailand to Southern Laos. However, species delimitation among the Mekong Glyphidrilus remains unclear because the key morphological traits in semi-aquatic earthworms are highly polymorphic. This study assessed the distinction between G. vangviengensis and G. mekongensis using allozyme electrophoresis. A total of 752 individuals collected from 33 localities were screened for 10 putative loci from seven enzymatic systems, revealing that G. vangviengensis and G. mekongensis are two distinct species, according to their different allelic patterns and high genetic distance. A low genetic differentiation within each species was indicated by the pairwise Nei's D and F_ST analyses, and the absence of population structure was detected by AMOVA and Bayesian structure analyses. However, a significant isolation by distance, but not vicariance, was observed, which is probably due to the river current causing translocation downstream and so gene flow between adjacent localities. The genetic diversity of the Mekong Glyphidrilus was relatively high and comparable to other earthworm taxa, and several localities showed deviation from Hardy–Weinberg equilibrium. An additional cryptic species from Ban Hat Khamphi, Loei, Thailand, was inferred.     

Morphological characteristics and ageing criteria of sand gazelle (<Emphasis Type="Italic">Gazella subgutturosa marica</Emphasis> Thomas, 1897) and their use for wildlife management

Data on some morphological characteristics of 165 male and 229 female sand gazelles (Gazella subgutturosa marica) collected during routine veterinary activity of a captive population at the King Khalid Wildlife Research Centre in central Saudi Arabia were examined for general baseline information on a little studied species. Measurements compared between the sexes and three age classes—juvenile, sub-adult and adult—included body mass, horn length (straight and curved), horn spread, neck circumference, shoulder height, forehead length, ear length and horn length (curved) to forehead and ear length ratios. All measurements were of known age individuals. The most valuable characteristics to use for age determination in the field are horn length (curved) and neck circumference for males and horn length (straight and/or curved) and shoulder height for females. The value of morphological characteristics correlated to known age animals for in situ management is discussed.     

Genetic Structure of Oryza rufipogon Griff. Natural Populations in Malaysia: Implications for Conservation and Genetic Introgression of Cultivated Rice

Thirty polymorphic Oryza sativa microsatellite loci (SSRs) were used to study population genetic structure of O. rufipogon Griff. natural populations in Malaysia. A total of 445 alleles were detected with an average of 14.8 alleles per locus in 176 individuals of O. rufipogon sampled from the states of Penang, Kedah, Kelantan and Terengganu where the natural populations are still found. The Kelantan population in the northeast of Peninsular Malaysia had the highest level of genetic diversity as measured by the mean number of alleles per locus, A_a?=?7.67, average number of effective alleles, A_e?=?5.50, percentage of polymorphic loci, P?=?100%, observed heterozygosity, H_o?=?0.631 and expected heterozygosity, H_e?=?0.798. In contrast, the Terengganu population in the east showed the lowest level of genetic diversity measured by the same criteria (A_a?=?4.23, A_e?=?2.10, P?=?100%, H_o?=?0.549 and H_e?=?0.449). Model–based clustering analysis using the STRUCTURE 2.2 program placed all the individuals into 12 clusters that corresponded to the geographic sampling locations. Neighbour-joining tree was constructed based on Nei’s genetic distance to further assess the genetic structure of the O. rufipogon individuals, showed good agreement (93.8%) with the model-based cluster analysis. However, the neighbour-joining tree identified sub-populations that STRUCTURE could not identify. The classification of individuals from the same populations under the same cluster supported the population differentiation. These two analyses seemed to indicate expansion of populations from the northeast of Peninsular Malaysia (Tumpat, Pasir Mas and Kota Bahru, Kelantan) not only to the immediate south of the region i.e. Terengganu but also into the northwest (i.e. Penang and Kedah) with the former being more recent. Oryza rufipogon accession IRGC105491 and O. sativa ssp. indica cultivar MR219, which were included in this study for comparisons with the local wild rice accessions, indicated that introgression of cultivated rice could change genetic composition and affect the population genetic structure of wild rice. This possibility should be carefully considered in plans to conserve this wild rice.     

High gene flow and complex treeline dynamics of <Emphasis Type="Italic">Larix</Emphasis> Mill. stands on the Taymyr Peninsula (north-central Siberia) revealed by nuclear microsatellites

Arctic treelines are facing a strong temperature increase as a result of recent global warming, causing possible changes in forest extent, which will alter vegetation-climate feedbacks. However, the mode and strength of the response is rather unclear, as potential changes are happening in areas that are very remote and difficult to access, and empirical data are still largely lacking. Here, we assessed the current population structure and genetic differentiation of Larix Mill. tree stands within the northernmost latitudinal treeline reaching ~?72° N in the southern lowlands of the Taymyr Peninsula (~?100° E). We sampled 743 individuals belonging to different height classes (seedlings, saplings, trees) at 11 locations along a gradient from ‘single tree’ tundra over ‘forest line’ to ‘dense forest’ stands and conducted investigations applying eight highly polymorphic nuclear microsatellites. Results suggest a high diversity within sub-populations (H_E?=?0.826–0.893), coupled, however, with heterozygote deficits in all sub-populations, but pronounced in ‘forest line’ stands. Overall, genetic differentiation of sub-populations is low (F_ST?=?0.005), indicating a region-wide high gene flow, although ‘forest line’ stands harbour few rare and private alleles, likely indicating greater local reproduction. ‘Single tree’ stands, located beyond the northern forest line, are currently not involved in treeline expansion, but show signs of a long-term refuge, namely asexual reproduction and change of growth-form from erect to creeping growth, possibly having persisted for thousands of years. The lack of differentiation between the sub-populations points to a sufficiently high dispersal potential, and thus a rapid northward migration of the Siberian arctic treeline under recent global warming seems potentially unconstrained, but observations show it to be unexpectedly slow.     

The population biology and genetics of the deep-sea spider crab,Encephaloides armstrongi Wood-Mason 1891 (Decapoda: Majidae)

Numerous specimens of the majid spider crab, Encephaloides armstrongi, were sampled from six stations (populations) between 150 and 650 m depth, on the continental slope off the coast of Oman. This extended the known geographic and bathymetric range of E. armstrongi, which is now known to occur along the continental margins of the northern Indian Ocean from the western coast of Burma to the coast of Oman. This band-like distribution is contiguous to the oxygen minimum zone in this region.The biology and genetics of populations of Encephaloides armstrongi separated by depth were studied. The overall sex ratio of the E. armstrongi sampled was male-biased (p less than 0.01; 3.3 males: 1 female; S_o = 0.538). However, sex ratio varied both between populations (p less than 0.01) and between size classes of crabs. Size frequency analysis indicated that the male and female crabs consisted of at least two instars, one between 6 and 16mm carapace length and one between 16 and 29 mm carapace length, which probably represented the terminal (pubertal) moult for most individuals. Accumulation of female crabs in the terminal instar probably caused the variation of sex ratio with size classes. Some male crabs grew to a larger size (up to 38 mm carapace length), possibly as a result of maturity at later instars.Length frequency distribution was significantly different between sexes (one-way ANOVA p less than 0.001). Within sexes, length frequency distributions varied between different populations. In both male and female Encephaloides armstrongi the individuals from a single population located at 150 m depth were significantly smaller than individuals at all other stations and were considered to represent a juvenile cohort. For female crabs no other significant differences were detected in length frequency between populations from 300 m to 650 m depth. Significant differences in length frequency were detected between male crabs from populations between 300 and 650 m depth.Horizontal starch gel electrophoresis was used to detect six enzyme systems coding for eight loci for individuals sampled from each population of Encephaloides armstrongi. Genetic identity (I) values between populations of E. armstrongi (I = 0.98-1.00) were within the normal range for conspecific populations. Observed heterozygosity (H_o = 0.080-0.146) was lower than expected heterozygosity (H_e = 0.111-0.160), but in the normal range detected for eukaryotic organisms.F-statistics were used to analyse between population (F_ST) and within population (F ) genetic structure. For both male and female E. armstrongi significant genetic differentiation was detected between the population located at 150 m depth and all other populations. Analyses of F_IS and F_ST, excluding the 150 m population indicated that for female E. armstrongi there was no significant structuring within or between populations. For male E. armstrongi significant heterozygote deficiencies were detected within populations and significant genetic differentiation between populations.The most likely explanations for the observations of the present study are: the population of Encephaloides armstrongi located at 150 m depth represented a juvenile cohort that is genetically distinct from deeper populations; female E. armstrongi formed a single population between 300 m and 650 m depth in the sampling area; male E. armstrongi were from two or more genetically distinct populations which are represented by different numbers of individuals at stations between 300 m and 650 m depth. This caused the observed significant differences in morphology (size distribition) and allele frequencies of male populations. It is likely that E. armstrongi exhibits gender-biased dispersal and that the crabs collected between 300 m and 650 m depth formed spawning aggressions. This also explains the bias in sex ratio of individuals sampled in the present study.     

Importance of over-dominance as the genetic basis of heterosis in rice

In populations derived from commercial hybrid rice combination Shanyou 10, F₁ heterosis and F₂ inbreeding depression were observed on grain yield (GYD) and number of panicles (NP). Using marker loci evenly distributed on the linkage map as fixing factors, the F₂ population was divided into sub-populations. In a large number of sub-populations, significant correlations were observed between heterozygosity and GYD, and between heterozygosity and NP. This was especially true in type III sub-populations in which the genotype of a fixing factor was heterozygotes. In type III sub-populations, 15 QTL for GYD and 13 QTL for NP were detected, of which the majority exhibited over-dominance effects for increasing the trait values. This study showed that over-dominance played an important role in the genetic control of heterosis in rice.     

Ecological investigations of the zooplankton community of Balsfjorden,northern Norway: Population structure and breeding biology of the chaetognath Sagitta elegans Verrill

The population dynamics of the chaetognath Sagitta elegans Verrill has been followed in Balsfjorden in 1976 and 1977. Seasonal variation in abundance, length-frequency distribution, growth in total length, and maturity stages are presented and discussed in relation to changes in hydrography.An annual generation of S. elegans was found, with a protracted and more or less continuous breeding season from May until October during 1977. The 1976 year-class consisted of two distinct length groups, both of which participated in the 1977 spawning. This spawning gave rise to possibly four sub-populations during 1977. The variation in numbers of sub-populations produced during the spawning season in 1976 and 1977 is discussed in relation to the hydrographical conditions in Balsfjorden. From November 1976 to March 1977 the abundance of S. elegans varied between 1 and 8 ind. · m^?3. The lowest value was recorded in May (0.9 ind. · m^?3). From September to December 1977 the population abundance was ≈2 ind. · m^?3.     

Comparative morphometric study of the invasive pearl oyster <Emphasis Type="Italic">Pinctada radiata</Emphasis> along the Tunisian coastline

In order to study the relative growth of the pearl oyster Pinctada radiata in Tunisia, a total of 330 individuals of this species were collected from six sites along the Tunisian coastline. Quantitative measurements of collected oysters were conducted for shell height, shell length, shell width, hinge length, height and width of the nacreous part and wet weight. The size structure of the sampled populations was described and the relative growth between different morphometric characteristics was estimated as allometric growth lines for the six P. radiata samples. It appeared that the majority of examined samples were dominated by large individuals that exceed a shell height of 42 mm. The maximum size (100.5 mm), recorded in Bizerta lagoon, is bigger than that recorded elsewhere in particular in the Red Sea. Size distribution analysis also showed that the majority of P. radiata samples were dominated by two or more size groups. Differences of allometric regression were found between the examined samples for the tested relationships. Moreover, the Factorial Discriminant Analysis, coupled with Ascending Hierarchic Classification, classified the sub-populations according to geographic locations.     

Investigation on the founder effect

The fitness of threeDrosophila melanogaster populations (A,B,C) and the crosses between them (A×B; A×C; B×C) has been studied in conditions of overlapping generations. Each line was subdivided into 4 sub-populations (1,2,3,4) differing in the phenotype of the founder flies (vestigial or wild type) and of which sub-populations 2 and 3 had the same gene composition. Fitness was estimated as the number of adult flies present in each population. The results suggest that: (1) a differentiation of fitness values is detectable between sub-populations founded from groups of flies having the same gene composition; (2) isolation does not seem to be a necessary condition for the observed differentiation. These results are discussed in connection with the evolutionary effects of random genetic drift. A working hypothesis has been advanced which would explain the observed results as dependent on complex interactions involving sexual dimorphism and interactions between genes.     

Population structure and genetic analysis of different utility types of mango (Mangifera indica L.) germplasm of Andhra Pradesh state of India using microsatellite markers

Genetic analysis of 90 mango genotypes including juicy, table, dual and pickle types from different parts of Andhra Pradesh of India was carried out employing 143 mango-specific microsatellite markers. Of the 143, 34 were new mango-specific microsatellite loci isolated in the course of the present investigation by constructing an (CA) _n and (TG) _n -enriched genomic library. Characterization of the 90 genotypes resulted in the detection of 301 alleles from 106 polymorphic loci with an average of 2.87 alleles per locus and polymorphism information content of 0.67. UPGMA cluster analysis grouped all the genotypes into two major groups with a genetic similarity range of 47–88 %. Grouping of the genotypes based on the utility type was observed only at sub-cluster level. Study of population structure by a model-based STRUCTURE analysis revealed the germplasm to exist in four gene pools. Overall F _st of 0.11 indicated genetic differentiation between the populations to be low. Analysis of molecular variance revealed that major proportion of the variation was within the individuals (62.25 %). The molecular marker-based study of genetic diversity suggests that the germplasm studied representing the kind of variability would be a valuable genetic resource for future breeding and association mapping in search for new and novel alleles.     

Genetic diversity and population structure of the red stingray,Dasyatis akajei inferred by AFLP marker

To examine population genetic diversity and variation of the red stingray Dasyatis akajei, samples from 1 freshwater region and 6 coastal localities within its distribution range were analyzed by using amplified fragment length polymorphism (AFLP) technology. A total of 207 loci were identified by 4 primer combinations from 87 individuals, 174 of which were polymorphic (84.1%). A high level of Nei's gene diversity was observed with the overall value of 0.230 ± 0.179. No significant genealogical clusters associated with sampling sites were revealed on the UPGMA tree. Both analysis of molecular variance (AMOVA, Φ_ST = 0.085, P = 0.00) and pairwise F_ST indicated significant genetic differentiation among four marine samples. However, no particular genetic differentiation was detected between marine and the limited sampling freshwater populations (AMOVA, Φ_CT = 0.056, P > 0.05). Except for the TZ vs. WZ (5.193), the gene flow estimates (N_m) demonstrated the effective immigrants were 1.918-2.976, suggesting low level dispersal between pairwise marine populations. Species-specific habits (demersal and sluggish habits) are probably responsible for the population structuring.     

The basic reproduction number and the probability of extinction for a dynamic epidemic model

We consider the spread of an epidemic through a population divided into n sub-populations, in which individuals move between populations according to a Markov transition matrix Σ and infectives can only make infectious contacts with members of their current population. Expressions for the basic reproduction number, R₀, and the probability of extinction of the epidemic are derived. It is shown that in contrast to contact distribution models, the distribution of the infectious period effects both the basic reproduction number and the probability of extinction of the epidemic in the limit as the total population size N → ∞. The interactions between the infectious period distribution and the transition matrix Σ mean that it is not possible to draw general conclusions about the effects on R₀ and the probability of extinction. However, it is shown that for n = 2, the basic reproduction number, R₀, is maximised by a constant length infectious period and is decreasing in ?, the speed of movement between the two populations.     

Moroccan Leishmania infantum: Genetic Diversity and Population Structure as Revealed by Multi-Locus Microsatellite Typing

Leishmania infantum causes Visceral and cutaneous leishmaniasis in northern Morocco. It predominantly affects children under 5 years with incidence of 150 cases/year. Genetic variability and population structure have been investigated for 33 strains isolated from infected dogs and humans in Morocco. A multilocus microsatellite typing (MLMT) approach was used in which a MLMtype based on size variation in 14 independent microsatellite markers was compiled for each strain. MLMT profiles of 10 Tunisian, 10 Algerian and 21 European strains which belonged to zymodeme MON-1 and non-MON-1 according to multilocus enzyme electrophoresis (MLEE) were included for comparison. A Bayesian model-based approach and phylogenetic analysis inferred two L.infantum sub-populations; Sub-population A consists of 13 Moroccan strains grouped with all European strains of MON-1 type; and sub-population B consists of 15 Moroccan strains grouped with the Tunisian and Algerian MON-1 strains. Theses sub-populations were significantly different from each other and from the Tunisian, Algerian and European non MON-1 strains which constructed one separate population. The presence of these two sub-populations co-existing in Moroccan endemics suggests multiple introduction of L. infantum from/to Morocco; (1) Introduction from/to the neighboring North African countries, (2) Introduction from/to the Europe. These scenarios are supported by the presence of sub-population B and sub-population A respectively. Gene flow was noticed between sub-populations A and B. Five strains showed mixed A/B genotypes indicating possible recombination between the two populations. MLMT has proven to be a powerful tool for eco-epidemiological and population genetic investigations of Leishmania.     

High-Density SNP Genotyping of Tomato (Solanum lycopersicum L.) Reveals Patterns of Genetic Variation Due to Breeding

The effects of selection on genome variation were investigated and visualized in tomato using a high-density single nucleotide polymorphism (SNP) array. 7,720 SNPs were genotyped on a collection of 426 tomato accessions (410 inbreds and 16 hybrids) and over 97% of the markers were polymorphic in the entire collection. Principal component analysis (PCA) and pairwise estimates of F _st supported that the inbred accessions represented seven sub-populations including processing, large-fruited fresh market, large-fruited vintage, cultivated cherry, landrace, wild cherry, and S. pimpinellifolium. Further divisions were found within both the contemporary processing and fresh market sub-populations. These sub-populations showed higher levels of genetic diversity relative to the vintage sub-population. The array provided a large number of polymorphic SNP markers across each sub-population, ranging from 3,159 in the vintage accessions to 6,234 in the cultivated cherry accessions. Visualization of minor allele frequency revealed regions of the genome that distinguished three representative sub-populations of cultivated tomato (processing, fresh market, and vintage), particularly on chromosomes 2, 4, 5, 6, and 11. The PCA loadings and F _st outlier analysis between these three sub-populations identified a large number of candidate loci under positive selection on chromosomes 4, 5, and 11. The extent of linkage disequilibrium (LD) was examined within each chromosome for these sub-populations. LD decay varied between chromosomes and sub-populations, with large differences reflective of breeding history. For example, on chromosome 11, decay occurred over 0.8 cM for processing accessions and over 19.7 cM for fresh market accessions. The observed SNP variation and LD decay suggest that different patterns of genetic variation in cultivated tomato are due to introgression from wild species and selection for market specialization.     

Frequencies of genes for coat colour and horns in Nordic cattle breeds

Gene frequencies of coat colour and horn types were assessed in 22 Nordic cattle breeds in a project aimed at establishing genetic profiles of the breeds under study. The coat colour loci yielding information on genetic variation were: extension, agouti, spotting, brindle, dun dilution and colour sided. The polled locus was assessed for two alleles. A profound variation between breeds was observed in the frequencies of both colour and horn alleles, with the older breeds generally showing greater variation in observed colour, horn types and segregating alleles than the modern breeds. The correspondence between the present genetic distance matrix and previous molecular marker distance matrices was low (r = 0.08 – 0.12). The branching pattern of a neighbour-joining tree disagreed to some extent with the molecular data structure. The current data indicates that 70% of the total genetic variation could be explained by differences between the breeds, suggesting a much greater breed differentiation than typically found at protein and microsatellite loci. The marked differentiation of the cattle breeds and observed disagreements with the results from the previous molecular data in the topology of the phylogenetic trees are most likely a result of selection on phenotypic characters analysed in this study.     

Occurrence and genetics of black‐eyed migratory locusts,Locusta migratoria (Orthoptera: Acrididae)

Black‐eyed Locusta migratoria appeared in albino locusts as a result of crossing between a short‐winged strain originating from Tsushima Island, Japan, and an albino strain originating from Okinawa Island. The black eye trait was recessive to the white eye trait because the crosses between black‐ and white‐eyed albino locusts produced only individuals with white eyes in the F₁ generation. In the F₂ generation, black‐ and white‐eyed individuals appeared in a ratio of 1:3, indicating that the black eye trait was controlled by a simple Mendelian unit. The black eye trait showed no genetic association with other traits including wing morph, adult body dimensions and classical morphometric ratios such as hind femur length / head width and forewing length / hind femur length.     

Intraspecific shape variation in horseshoe crabs: The importance of sexual and natural selection for local adaptation

A morphometric analysis of the body shape of three species of horseshoe crabs was undertaken in order to infer the importance of natural and sexual selection. It was expected that natural selection would be most intense, leading to highest regional differentiation, in the American species Limulus polyphemus, which has the largest climatic differences between different populations. Local adaptation driven by sexual selection was expected in males but not females because horseshoe crab mating behaviour leads to competition between males, but not between females. Three hundred fifty-nine horseshoe crabs from nine populations, representing three species, were analyzed using a digitizer to position sixty morphometric landmarks in a three-dimensional space. Discriminant analysis revealed strong regional structuring within a species, which suggests strong philopatry, and showed the existence of geographically-based intraspecific variation. An admixture analysis showed regional intraspecific differentiation for males and females of L. polyphemus and males of the Asian horseshoe crab Carcinoscorpius rotundicauda, but not for females of C. rotundicauda and another Asian horseshoe crab, Tachypleus gigas. Differences in shape variation between sexes were tested with F-tests, which showed lower intrapopulation morphometric variation in males than females. These results indicate a lower degree of local adaptation on body shape in C. rotundicauda and T. gigas than in L. polyphemus and a lower degree of local adaptation in females than in males.     

Genetic analysis of ratmouth barbell (Ptychidio jordani Myers) from different geographic sub-populations in the Pearl River Basin using microsatellite markers

Thirteen polymorphic microsatellite markers were used to study the genetic variation of Ptychidio jordani sampled from the three sites of Liuzhou, Guiping and Yunan in the Pearl River Basin with the help of local fishers. Allele numbers ranged from 2 to 19 and fragment sizes ranged from 108 to 288. Average polymorphism information content (PIC), average observed heterozygosity (Ho) and average expected heterozygosity (He) were 0.439917, 0.4147 and 0.4986, respectively, which indicate a comparatively high level of genetic diversity. The coefficient of genetic differentiation ( G _st) between the two sub-populations ranged from 0.0074 to 0.0156, which shows little differentiation between sub-populations. amova analysis also offered evidence of weak differentiation with 0.53% variation between sub-populations, 99.47% variation within sub-populations and the F _st = 0.00531. The morphological variation among geographic sub-populations might result from different habitats. The correlation between genotype and morphological characters was analyzed and a significant correlation found between the genotype of microsatellite locus Hlj038 and the ratio of body depth and body length. The results suggest a possible linkage between this locus and these morphological characters.     

Modeling combined transport of water and charged graded-size molecules across the glomerular capillary wall

Clearance studies using various probe molecules established that the passage of molecules/proteins across the glomerular capillary wall of mammalian kidneys is increasingly restricted as their size and net negative charge increase. An extended mathematical model, based on the Fiber Matrix theory, was developed to describe the dynamics of the size- and charge-selective functions of the glomerular capillary barrier using mainly its hemodynamic, morphometric, and electrostatic variables. The glomerular basement membrane was represented as a homogeneous three-dimensional network of fibers of uniform length (L_f), radius (R_f), and packing density (N_fv) and characteristic Darcy permeability. The model was appropriate for simulating fractional clearance data of neutral and charged solutes from an experimental modeling exercise. We believe that the L_f and R_f best-fit numerical values may signify new insights for the diagnosis of some human nephropathies.     

Genetic and morphological variation of three freshwater lake populations of Coilia ectenes (Engraulidae)

Population structure of the important commercial fish, Coilia ectenes was investigated in samples from three freshwater lakes in the Eastern China using a multivariate approach of morphometries and mitochondrial DNA control region sequencing. A total of eighteen morphological distances of truss method and eight morphometric variables were taken from each fish. Multivariate analyses of the morphometric data revealed significant morphological differences among the three lake populations, especially for those samples from Taihu Lake. Discriminant functions were used to compare sites, and these permitted an 83% success rate in distinguishing fish from the three sites. However, no obviously geographical differentiation was found among those populations of C. ectenes based on the genetic data. In the AMOVA analysis, only 2.2% genetic variability came from different populations, and most of them were present within the sub-populations. Experience a recent population expansion and some movement of fish among those areas, quite possibly enough to bring about relative genetic homogeneity, but there is insufficient to prevent the three populations from differing phenotypically. The diversified environmental factors may be playing an important role in shaping morphological variations among those populations.