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1.
This study investigated the utility of microsatellite markers for providing information on levels of population connectivity
for a low dispersing reef fish in New South Wales (NSW), Australia, at scales ≤400 km. It was hypothesized that the temperate
damselfish Parma
microlepis, which produces benthic eggs and has limited post-settlement dispersal, would exhibit spatial genetic structure and a significant
pattern of isolation-by-distance (IBD). A fully nested hierarchical sampling design incorporating three spatial scales (sites,
location and regions, separated by 1–2, 10–50 and 70–80 km respectively) was used to determine genetic variability at seven
microsatellite loci. Broad-scale genetic homogeneity and lack of IBD was well supported by single and multi-locus analyses.
The proportion of the total genetic variation attributable to differences among regions, locations or sites was effectively
zero (Φ/R-statistics ≤0.007). The geographic distribution of genetic diversity and levels of polymorphism (H
E 0.21–0.95) indicate high mutation rates, large effective population sizes, and high rates of gene flow. Significant gene
flow may be driven by factors influencing pre-settlement dispersal, including the East Australian Current (EAC) and habitat
continuity. Genetic connectivity may not reflect demographically important connectivity, but does imply that P. microlepis populations are well connected from an evolutionary perspective. Total observed genetic diversity was accounted for within
1–2 km of reef and could be represented within small Marine Protected Areas. Reef fishes in NSW which have life histories
similar to P. microlepis (e.g. pre-settlement durations ≥2 weeks) are also likely to exhibit genetic homogeneity. Genetic markers are, therefore,
most likely to provide information on demographically relevant connectivity for species with lower dispersal capabilities,
small population sizes, short life spans, and whose habitats are rare, or patchily distributed along-shore.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
2.
Pelagic dispersal of larvae in sessile marine invertebrates could in principle lead to a homogeneous gene pool over vast distances,
yet there is increasing evidence of surprisingly high levels of genetic differentiation on small spatial scale. To evaluate
whether larval dispersal is spatially limited and correlated with distance, we conducted a study on the widely distributed,
viviparous reef coral Seriatopora hystrix from the Red Sea where we investigated ten populations separated between ~0.150 km and ~610 km. We addressed these questions
with newly developed, highly variable microsatellite markers. We detected moderate genetic differentiation among populations
based on both F
ST and R
ST (0.089 vs. 0.136, respectively) as well as considerable heterozygote deficits. Mantel tests revealed isolation by distance
effects on a small geographic scale (≤20 km), indicating limited dispersal of larvae. Our data did not reveal any evidence
against strictly sexual reproduction among the studied populations. 相似文献
3.
Documenting the scale of movement among populations is an important challenge for marine ecology. Using nine microsatellite markers, evidence of genetic structure in a marine kelp, the sea palm Postelsia palmaeformis Ruprecht, was examined in the vicinity of Cape Flattery, Washington state, USA (48° 24′ N, 124°44′ W). Genetic clustering analysis implemented without reference to geographic structure strongly suggested that a number of distinct genetic clusters existed among the 245 plants sampled in August in the years 1997–2001. Subsequent analysis showed that clustering was associated with geographically defined populations both among (km scale) and within (m scale) sampling sites. F
st analysis of geographically defined populations revealed significant genetic differentiation among populations of plants as little as 5 m apart, evidence of genetic structuring at even smaller scales, and a sharp increase in F
st across populations separated by up to 23 m. F
st values were also high and approximately unchanging (F
st=0.470) for populations separated by greater distances (up to 11 km), consistent with a scenario of rare dispersal by detached, floating plants carried by variable currents. The results corroborate natural history observations suggesting that P. palmaeformis has extremely short (1–3 m) spore dispersal distances, and indicate that the dynamics of sea palm populations are more affected by local processes than recruitment from distant populations. 相似文献
4.
Nathan L. Kirk Jason P. Andras C. Drew Harvell Scott R. Santos Mary Alice Coffroth 《Marine Biology》2009,156(8):1609-1623
Numerous marine invertebrates form endosymbiotic relationships with dinoflagellates in the genus Symbiodinium. However, few studies have examined the fine-scale population structure of these symbionts. Here, we describe the genetic
structure of Symbiodinium type “B1/B184” inhabiting the gorgonian Gorgonia
ventalina along the Florida Keys. Six polymorphic microsatellite loci were utilized to examine 16 populations along the Upper, Middle,
and Lower Keys spanning a range of ~200 km. Multiple statistical tests detected significant differentiation in 54–92% of the
120 possible pairwise comparisons between localities, suggesting low levels of gene flow in these dinoflagellates. In general,
populations clustered by geographic region and/or reefs in close proximity. Some of the sharpest population differentiation
was detected between Symbiodinium from deep and shallow sites on the same reef. In spite of the high degree of population structure, alleles and genotypes
were shared among localities, indicating some connectivity between Symbiodinium populations associated with G. ventalina.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
5.
Endemism and dispersal: comparative phylogeography of three surgeonfishes across the Hawaiian Archipelago 总被引:1,自引:0,他引:1
To evaluate the hypothesis that a general correlation exists between species range size and dispersal ability, we surveyed
mitochondrial cytochrome b sequence variation in three surgeonfish species with vastly different ranges: Ctenochaetus strigosus, Hawaiian endemic, N = 531; Zebrasoma flavescens, North Pacific, N = 560; Acanthurus nigrofuscus, Indo-Pacific, N = 305. Collections were made throughout the 2,500 km expanse of the Hawaiian Archipelago and adjacent Johnston Atoll. Analyses
of molecular variance demonstrate that all three species are capable of maintaining population connectivity on a scale of
thousands of km (all species global ΦST = NS). However, rank order comparison of pairwise ΦST results and Exact test P-values revealed modest but significantly different patterns of gene flow among the three species surveyed, with the degree
of genetic structure increasing as range size decreases (P = 0.001). These results are consistent with mtDNA surveys of four additional Hawaiian reef fauna in which a wide-spread Indo-Pacific
species exhibited genetic homogeneity across the archipelago, while three endemics had significant population subdivision
over the same range. Taken together, these seven cases invoke the hypothesis that Hawaii’s endemic reef fishes evolved from
species with reduced dispersal ability that, after initial colonization, could not maintain contact with parent populations.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
6.
Coupled bio-physical models of larval dispersal predict that the Costa Rica–Panama (CR–PAN) reefs should constitute a demographically
isolated region in the western Caribbean. We tested the hypothesis that CR–PAN coral reef fish populations would be isolated
from Mesoamerican Barrier Reef System (MBRS) populations. To test that, we assessed population genetic structure in bicolor
damselfish (Stegastes partitus) from both regions. Adult fish were genotyped from five reefs in CR–PAN and from four reefs along the MBRS at 12 microsatellite
loci. Between-region F
ST (F
ST = 0.0030, P < 0.005) and exact test (x
2 = 74.34, df = 18, P < 0.0001) results indicated that there is weak but significant genetic differentiation between regions, suggesting some restriction
in connectivity along the Central American coastline, as predicted by bio-oceanographic models. Additionally, there is among-site
genetic structure in the CR–PAN region, relative to the MBRS and between regions, suggesting higher self-recruitment within
CR–PAN. This finding may be explained by differences in habitat characteristics. 相似文献
7.
Tina Fredsted Mikkel H. Schierup Linn F. Groeneveld Peter M. Kappeler 《Behavioral ecology and sociobiology》2007,61(6):943-954
Mating system and dispersal patterns influence the spatio-genetic structure within and between populations. Among mammals,
monogamy is rare, and its socio-genetic consequences have not been studied in detail before. The goal of our study was to
investigate population history, demographic structure, and dispersal patterns in a population of pair-living fat-tailed dwarf
lemurs, Cheirogaleus medius, a small, nocturnal primate from western Madagascar, and to infer their underlying behavioral mechanisms. Tissue samples
for DNA extraction were obtained from a total of 140 individuals that were captured in two subpopulations about 3 km apart.
Analyses of mtDNA variability at the population level revealed very low levels of genetic variability combined with high haplotype
diversity, which is indicative of a recent population bottleneck. We found no evidence for spatial clustering of same-sexed
individuals with identical haplotypes within each of two subpopulations but significant clustering between them. Thus, a high
level of local subpopulation differentiation was observed (F
ST = 0.230). The sexes showed equal variances in the number of individuals representing each haplotype, as well as equal levels
of aggregation of identical haplotypes. Hence, both sexes disperse from their natal area, one pattern expected in a pair-living
mammal. There is a possibility of behavioral and social flexibility in this species, however, because we documented pronounced
differences in density and sex ratio between the two subpopulations, suggesting that single study sites or populations may
not be representative of a given local population or even species. 相似文献
8.
Jennifer K. Schultz Richard L. Pyle Edward DeMartini Brian W. Bowen 《Marine Biology》2007,151(1):167-175
Color variation is used in taxonomic classification of reef fishes, but it may not reliably indicate evolutionary divergence.
In the central Pacific, there are three color morphs of the flame angelfish, Centropyge loriculus: a red morph that occurs primarily in the Hawaiian archipelago, the endemic Marquesan color morph with reduced black markings,
and an orange morph that occurs throughout the rest of Oceania. The red and orange morphs co-occur at Johnston Atoll (1,300 km
south of Hawai’i), but intermediate forms have not been reported. To determine whether the three color morphs represent distinct
evolutionary lineages, we compared 641 base pairs of mitochondrial cytochrome b. Forty-one closely related haplotypes were observed in 116 individuals. Analysis of molecular variance (AMOVA) indicated
no significant genetic structure among color morphs (ΦST = 0.011, P = 0.147). Likewise, there was no significant pairwise structure between sampling locations, separated by up to 5,700 km,
after a Bonferroni correction (ΦST = 0.000–0.080, P = 0.0130–0.999). Genetic studies in conjunction with larval distribution data indicate that Centropyge species are highly dispersive. While there is a strong geographic component to the distribution of color morphs in C. loriculus, we find no evidence for corresponding genetic partitioning. We do not rule out an adaptive role for color differentiation,
but our data do not support emerging species. 相似文献
9.
Two regions of the mitochondrial genome (cytochrome oxidase I and ATPase 8–ATPase 6) were used to examine the population genetic
structure of New Zealand’s endemic abalone (Haliotis iris). Samples were collected from 28 locations around New Zealand between January 2005 and February 2008. At least four phylogeographic
breaks were present and occurred across the Chatham rise, in the western Cook Strait region, along the southeast coast of
the South Island, and at East Cape in the North Island. Gene flow across the Chatham rise is probably limited due to infrequent
dispersal across large geographic distances (~850 km), while factors limiting gene flow around the North and South Islands
are less clear, and understanding these may require intense temporal and spatial sampling in complex hydrographic regions.
High genetic diversity and weak genetic structure may be a general feature of abalone potentially reflecting large and/or
ancient populations. 相似文献
10.
Kate L. Winters Lynne van Herwerden J. Howard Choat D. R. Robertson 《Marine Biology》2010,157(8):1679-1691
Phylogenetic, phylogeographic, population genetic and coalescence analyses were combined to examine the recent evolutionary
history of the widespread Indo-Pacific parrotfish, Scarus psittacus, over a geographic range spanning three marine biogeographic realms. We sequenced 164 individuals from 12 locations spanning
17,000 km, from 55oE to 143oW, using 322 base pairs of mitochondrial control region (D-loop). S. psittacus displayed high haplotype (h = 0.83–0.98), but low nucleotide (<1%) diversity. Most (>83%) genetic variation was within populations. AMOVA revealed significant
partitioning and identified five geographic groups. These included one central population and four populations peripheral
to the centre. The central population occupied reefs from Western Australia to Tahiti and represented the central Indo-Pacific
biogeographic realm. Cocos Keeling was distinct from central and western Indo-Pacific biogeographic realms occupying a position
intermediate to these. Peripheral populations (Hawaii, Marquesas) represented the eastern Indo-Pacific biogeographic realm,
while Seychelles represented the western Indo-Pacific biogeographic realm. All but the central population expanded (<163 kya).
Whilst all populations experienced major sea level and SST changes associated with Pleistocene glaciation cycles, the genetic
structure of the central population was relatively homogenous unlike the remaining genetically distinctive populations. 相似文献
11.
Spatial and temporal genetic homogeneity in the Arctic surfclam (<Emphasis Type="Italic">Mactromeris polynyma</Emphasis>) 总被引:1,自引:0,他引:1
Commercially harvested marine bivalve populations show a broad range of population-genetic patterns that may be driven by
planktonic larval dispersal (gene flow) or by historical (genetic drift) and ecological processes (selection). We characterized
microsatellite genetic variation among populations and year classes of the commercially harvested Arctic surfclam, Mactromeris polynyma, in order to test the relative significance of gene flow and drift on three spatial scales: within commercially harvested
populations in the northwest Atlantic; among Atlantic populations; and between the Atlantic and Pacific oceans. We found small
nonsignificant genetic subdivision among eight populations from the northwest Atlantic (F
ST = 0.002). All of these Atlantic populations were highly significantly differentiated from a northeast Pacific population
(F
ST = 0.087); all populations showed high inbreeding coefficients (F
IS = 0.432). We tested one likely source of heterozygote deficits by aging individual clams and exploring genetic variation
among age classes within populations (a temporal Wahlund effect). Populations showed strikingly different patterns of age
structure, but we found little differentiation among age classes. In one case, we were able to analyze genetic diversity between
age classes older or younger than the advent of intensive commercial harvesting. The results generally suggest spatially broad
and temporally persistent genetic homogeneity of these bivalves. We discuss the implications of the results for the biology
and management of surfclam populations.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
12.
Christine E. Thacker Andrew R. Thompson Dawn M. Roje Emily Y. Shaw 《Marine Biology》2008,153(3):375-385
Species of the reef goby genus Gnatholepis exhibit enormous geographic ranges with little evidence of population segregation detectable based on mitochondrial DNA.
To determine if genetic differentiation is evident with more rapidly evolving markers, seven microsatellite loci were screened
from the species Gnatholepis anjerensis and G. scapulostigma and population segregation was tested among fish from across the South Pacific. Both AMOVA and pairwise F
ST analyses showed that, in concordance with previous mitochondrial results, most genetic variance occurs within individual
populations, as population differentiation is evident only over the largest distances (>3,700 km). This result is contrasted
with previous studies demonstrating that despite their relatively long larval periods, some gobiid fishes exhibit population
differentiation on small (<100 km) geographic scales. Coalescence analysis showed that current Pacific populations of these
species originated in the Pleistocene, presumably related to sea level fluctuations associated with episodes of glaciation.
However, rate analysis based on a phylogeny of Gnatholepis species indicates that the species themselves are much older, consistent with a complex history of rapid, short-term population
contractions and expansions, with corresponding rapid dispersal. 相似文献
13.
Mirimin Luca Westgate Andrew Rogan Emer Rosel Patricia Read Andrew Coughlan Jamie Cross Tom 《Marine Biology》2009,156(5):821-834
The understanding of population structure and gene flow of marine pelagic species is paramount to monitoring, management and
conservation studies. Such studies are often hampered by the potentially high dispersal behavior of the species, the lack
of obvious geographical barriers in the marine environment and the scarce sample availability. Short-beaked common dolphins
(Delphinus delphis) are widespread in coastal and open-ocean habitats of the North Atlantic Ocean, nevertheless population structure and migratory
patterns are poorly understood. Furthermore, concern has been raised about the status of the species because large numbers
of dolphins have been taken incidentally in several fisheries throughout the North Atlantic in the past decades. In the present
study, a large number of individual samples were obtained from seasonal and spatial aggregations of common dolphins from western
(wNA) and eastern North Atlantic (eNA) regions, mostly using opportunistic sampling (i.e. from incidental entanglement in
fishing gear or beach-cast carcasses). Genetic variability was investigated using nuclear (14 microsatellite loci) and mitochondrial
(360 bp of the control region) genetic markers. Levels of genetic diversity were relatively high in all sampled areas and
no evidence of recent reduction of effective population size (i.e. bottleneck) was detected at the nuclear loci. Significant
population structure was detected between the two main regions (wNA and eNA) where it appeared to be more pronounced at mitochondrial
(F
ST = 0.018, P < 0.001) than nuclear markers (F
ST = 0.005, P < 0.05), indicating the presence of at least two genetically distinct populations of common dolphins in the North Atlantic
Ocean. In contrast, no significant genetic structure was detected between temporal aggregations of dolphins from within the
same region, suggesting possible seasonal movement patterns at a regional scale. The observed levels of genetic differentiation
between classes of markers are discussed here as a possible consequence of migratory patterns or recent population subdivision.
An erratum to this article can be found at 相似文献
14.
Zoë Anne Doubleday Jayson M. Semmens Adam J. Smolenski Paul W. Shaw 《Marine Biology》2009,156(6):1183-1192
Five polymorphic microsatellite loci were developed and then used to assess the population genetic structure of a commercially
harvested merobenthic octopus species (Octopus maorum) in south-east Australian and New Zealand (NZ) waters. Beak and stylet morphometrics were also used to assess population
differentiation in conjunction with the genetic data. Genetic variation across all loci and all sampled populations was very
high (mean number alleles = 15, mean expected heterozygosity = 0.85). Microsatellites revealed significant genetic structuring
(overall F
ST = 0.024, p < 0.001), which did not fit an isolation-by-distance model of population differentiation. Divergence was observed between
Australian and NZ populations, between South Australia and north-east Tasmania, and between two relatively proximate Tasmanian
sites. South Australian and southern Tasmanian populations were genetically homogeneous, indicating a level of connectivity
on a scale of 1,500 km. Morphometric data also indicated significant differences between Australian and NZ populations. The
patterns of population structuring identified can be explained largely in relation to regional oceanographic features. 相似文献
15.
Lingcod, Ophiodon elongatus Girard, have a 3-month pelagic larval stage and are an important recreational and commercial species on the west coast of
North America. Cytochrome-c oxidase I sequences from tissue samples were used to characterize population structure and infer
patterns of gene flow from California to Alaska. No significant genetic structure was found when estimates of Wright’s F
ST (i.e., ΦST) were generated among all populations sampled. Nesting populations within regions, however, indicated that the inner coast
of Washington State is distinct, a result corroborating previous allozyme work. Coalescent-based estimates of gene flow indicate
that although migration can be high from an evolutionary perspective, nearly half of all comparisons among populations showed
no gene flow in at least one direction. From an ecological perspective, moderate migration rates (Nm < 10) among most populations provide surprisingly limited connectivity at large (∼ 1,000 km) and small (∼100 km) spatial
scales. Coalescent-based estimates also show that gene flow between the inner and the outer coasts is asymmetric, a result
consistent with prevailing surface currents. Because the expected inter-locus variances for coalescent-based estimates of
gene flow are likely large, future work will benefit from analyses of nuclear DNA markers. However, limited demographic connectivity
on large spatial scales may help explain why stock recovery has been uneven, with greater recovery in the northern (87% rebuilt)
than in the southern (24% rebuilt) fishery region, supporting a regional management strategy. These results suggest that despite
a 3-month pelagic larval stage, some areas may be effectively closed with respect to both population dynamics and fishery
management issues. 相似文献
16.
The objective of our study was to investigate the spatial distribution and genetic structure of a solitary primate at the microgeographical scale of adjacent local populations. We obtained spatial data and tissue samples for mtDNA analysis from 205 gray mouse lemurs (Microcebus murinus) captured along transects and within 3 grid systems within a 12.3 km2 area in Kirindy Forest, western Madagascar. Our capture data revealed that, even though the forest was continuous, gray mouse lemurs were not evenly distributed, and that daily and maximum dispersal distances were significantly greater in males. The frequency distribution of 22 mtDNA D-loop haplotypes was highly skewed. Nine haplotypes were unique to males, indicating male-mediated gene flow from surrounding areas. The geographic distribution of haplotypes revealed that males were also more dispersed than females. Females with the same haplotype showed a tendency towards spatial aggregation, and the correlation between genetic and geographic distances was higher in females. In several areas of the forest, however, spatially clustered females were not of the same haplotype, and females were not always found in clusters. Hence, in contrast to suggestions from previous studies, matrilineal clustering is not the only way females are socially organized. In addition, our study revealed heterogeneity and patterns in population structure that were not evident at smaller spatial scales, some of which may be relevant for designing conservation strategies.Communicated by C. Nunn 相似文献
17.
Assignment of individuals to populations based upon genetic data is an important ecological problem that requires many polymorphic
markers, often more than are available using single locus techniques. To demonstrate the utility of amplified fragment length
polymorphisms (AFLP) in studying larval dispersal and recruitment in coral populations, two sets of AFLP primers were used
to genotype colonies of the coral Agaricia agaricites Linnaeus from three widely separated geographic locations: the Bahamas (23°28′N, 75°42′W) and Key Largo, Florida (24°55′N,
80°31′W—two sites separated by 12 km) in 1995, and the Flower Garden Banks (FGB) in the Gulf of Mexico (27°55′N,93°36′W) in
1997. In addition to adult samples from each site, recruits were collected from settling plates placed on the East FGB for
1 year (1997–1998). The AFLP technique yielded 45 polymorphic markers. An analysis of molecular variance (AMOVA) showed significant
genetic differences among the four adult populations, even between the two Key Largo sites. The recruits were significantly
different from all adult populations except those from the FGB. Discriminant function analysis and the program AFLPOP were
used to assign individuals to populations. Using the adult AFLP-banding patterns to build the statistical models, both procedures
correctly assigned the majority of adults to their respective populations in simulations and assigned all but one of the recruits
to the Flower Garden population from where they were collected . The AFLP technique provides a simple and adaptable population
assignment method for studying recruitment processes in A. agaricites and other coral species.
Electronic Supplementary Material Supplementary material is available for this article at 相似文献
18.
Lauren M. Mathews 《Marine Biology》2007,152(3):645-655
Despite the apparent absence of geographic barriers, connectivity among marine populations may be restricted by, for example,
ecological or behavioral mechanisms. In such cases, populations may show genetic differentiation even over relatively small
spatial scales. Here, mitochondrial sequence data from the cytochrome oxidase I (COI) gene and seven polymorphic microsatellite
markers were used to investigate fine geographic scale population genetic structure in the snapping shrimp Alpheus angulosus, a member of the A. armillatus species complex, from collections in Florida, Jamaica, and Puerto Rico carried out from 1999 to 2005. The COI data showed
a deep divergence that separated these samples into two mitochondrial clades, but this divergence was not supported by the
microsatellite data. The COI data reflect past population divergence not reflected in extant population structure on the whole
genome level. The microsatellite data also revealed evidence for moderate population structure between populations as close
as ∼10 km, and no evidence for isolation by distance, as divergences between near populations were at least as strong as those
between more broadly separated populations. Overall, these data suggest a role for restricted gene flow between populations,
though the mechanisms that reduce gene flow in this taxon remain unknown. 相似文献
19.
Phylogeography and Limited Genetic Connectivity in the Endangered Boring Giant Clam across the Coral Triangle 总被引:1,自引:0,他引:1
TIMERY S. DeBOER MATTHEW D. SUBIA MARK V. ERDMANN KATIE KOVITVONGSA PAUL H. BARBER 《Conservation biology》2008,22(5):1255-1266
Abstract: The Coral Triangle is the global center of marine biodiversity; however, its coral reefs are critically threatened. Because of the bipartite life history of many marine species with sedentary adults and dispersive pelagic larvae, designing effective marine protected areas requires an understanding of patterns of larval dispersal and connectivity among geographically discrete populations. We used mtDNA sequence data to examine patterns of genetic connectivity in the boring giant clam (Tridacna crocea) in an effort to guide conservation efforts within the Coral Triangle. We collected an approximately 485 base pair fragment of mtDNA cytochrome c oxidase 1 (CO1) from 414 individuals at 26 sites across Indonesia. Genetic structure was strong between regions (φST=0.549, p < 0.00001) with 3 strongly supported clades: one restricted to western Sumatra, another distributed across central Indonesia, and a third limited to eastern Indonesia and Papua. Even within the single largest clade, small but significant genetic structure was documented (φST=0.069, p < 0.00001), which indicates limited gene flow within and among phylogeographic regions. Significant patterns of isolation by distance indicated an average dispersal distance of only 25–50 km, which is far below dispersal predictions of 406–708 km derived from estimates of passive dispersal over 10 days via surface currents. The strong regional genetic structure we found indicates potent limits to genetic and demographic connectivity for this species throughout the Coral Triangle and provides a regional context for conservation planning. The recovery of 3 distinct evolutionarily significant units within a well‐studied taxonomic group suggests that biodiversity in this region may be significantly underestimated and that Tridacna taxa may be more endangered than currently recognized. 相似文献
20.
The population genetic structure of the neon damselfish (Pomacentrus coelestis) in the northwestern Pacific Ocean was revealed by the hypervariable control region of the mitochondrial gene (343 bp). In
total, 170 individuals were sampled from 8 localities distributed between Taiwan and Japan, and 71 haplotypes were obtained
through sequence alignment. High haplotype diversity (h = 0.956 ± 0.008) with low nucleotide diversity (π = 0.010 ± 0.006) was observed, and the results of the mismatch distribution test suggested that a historical population expansion
after a period of population bottleneck might have occurred among P. coelestis populations. Based on the results of the UPGMA tree and AMOVA (Φct = 0.193, P < 0.05) analyses, fish populations from eight localities could be divided into two groups: one includes populations from localities
around mainland Japan, and the other includes those from Okinawa and southern Taiwan. A genetic break was found between populations
from mainland Japan and Okinawa, and this break was congruent with the pattern of phenotypic variations documented in previous
studies. This evidence supports the latitudinal variation of reproductive traits among P. coelestis populations likely being genetically based. It is suggested that the changes in sea level and sea surface temperatures during
past glaciations might have resulted in population bottlenecks in P. coelestis and the modern populations in the northern West Pacific are likely the results of recolonization after such events. The Kuroshio
Current acts not only as a vehicle for larval transport along its pathway (between populations in southern Taiwan and Okinawa)
but also as a barrier for larval dispersal across the Kuroshio axis (between populations in mainland Japan and Okinawa).
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献