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1.
Population differentiation of the Atlantic spotted dolphin (Stenella frontalis) in the western North Atlantic, including the Gulf of Mexico 总被引:4,自引:2,他引:2
Information about the genetic population structure of the Atlantic spotted dolphin [Stenella frontalis (G. Cuvier 1829)] in the western North Atlantic would greatly improve conservation and management of this species in USA
waters. To this end, mitochondrial control region sequences and five nuclear microsatellite loci were used to test for genetic
differentiation of Atlantic spotted dolphins in the western North Atlantic, including the Gulf of Mexico (n=199). Skin tissue samples were collected from 1994–2000. Significant heterozygote deficiencies in three microsatellite loci
within samples collected off the eastern USA coast prompted investigation of a possible Wahlund effect, resulting in evidence
for previously unsuspected population subdivision in this region. In subsequent analyses including three putative populations,
two in the western North Atlantic (n=38, n=85) and one in the Gulf of Mexico (n=76), significant genetic differentiation was detected for both nuclear DNA (R
ST=0.096, P≤0.0001) and mitochondrial DNA (Φ
ST=0.215, P≤0.0001), as well as for all pair-wise population comparisons for both markers. This genetic evidence for population differentiation
coupled to known biogeographic transition zones at Cape Hatteras, North Carolina and Cape Canaveral, Florida, USA, evidence
of female philopatry, and preliminary support for significant genetic differences between previously documented morphotypes
of Atlantic spotted dolphins in coastal and offshore waters all indicate that the biology and life history of this species
is more complex than previously assumed. Assumptions of large, panmictic populations might not be accurate in other areas
where S. frontalis is continuously distributed (e.g., eastern Atlantic), and could have a detrimental effect on long-term viability and maintenance
of genetic diversity in this species in regions where incidental human-induced mortality occurs.
相似文献
Lara D. AdamsEmail: |
2.
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
3.
Megrim, Lepidorhombus whiffiagonis, and four spot megrim, Lepidorhombus boscii, are two marine fish species of high commercial interest. Despite their quite heavy exploitation little is known on the genetic
structure of their populations. The present work aimed at characterizing the first seven microsatellites markers available
for the two megrim species. These new markers were in a second step employed to describe the population structure of the two
species among their almost entire habitat range (Atlantic and Mediterranean samples). Our study confirmed the existence of
a strong genetic difference between Atlantic and Mediterranean megrim species already described in the literature for L. whiffiagonis on the basis of variations at ribosomal genes. Additionally our analysis gave the first evidences of a strong genetic differentiation
among Atlantic populations in both megrim species (within Atlantic global FST in L. whiffiagonis and L. boscii were respectively 0.158 and 0.145). When describing megrim population structure, the comparison between allele-frequency-based
tests (FST comparisons) and genotype-based inferences (Bayesian approach) gave evidences of a hierarchical structure of the populations.
In conclusion, our work enlighten the existence of two different stocks within the Atlantic Ocean and one in the Mediterranean
Sea that will clearly need to be managed separately. As the present results do not fully support the current megrim stock
boundaries they will surely help to rethink megrim management policies in the future. 相似文献
4.
5.
Molecular genetic variation in tarpon (<Emphasis Type="Italic">Megalops atlanticus</Emphasis> Valenciennes) in the northern Atlantic Ocean 总被引:2,自引:0,他引:2
The tarpon (Megalops atlanticus) is a highly valued game fish and occasional food fish in the eastern and western Atlantic Ocean. Tarpon have a high capacity for dispersal, but some regional biological differences have been reported. In this study we used two molecular genetic techniques—protein electrophoresis of nuclear DNA loci, and restriction fragment length polymorphism analysis of the mitochondrial DNA (mtDNA)—to assess this species population genetic structure in the eastern (coastal waters off Gabon and Sierra Leone, Africa) and western (coastal waters off Florida, Caribbean Sea) Atlantic Ocean north of the equator. Genetic differentiation was observed between tarpon from Africa and tarpon from the western Atlantic Ocean. A unique allele and haplotype, significant differences in allozyme allele and mtDNA haplotype frequencies between the African and western Atlantic samples, and significant FST analyses suggest that levels of gene flow between tarpon from these two regions is low. Among the western Atlantic Ocean collections, genetic diversity values and allele and haplotype frequencies were similar. AMOVA analyses also showed a degree of genetic relatedness among most of the western Atlantic Ocean collections: however, some significant population structuring was detected in the allozyme data. A regional jackknifed FST analysis indicated the distinction of the Costa Rica population from the other western Atlantic populations and, in pairwise analyses, FST values tended to be higher (i.e., genetic relatedness was lower) when the Costa Rican sample was paired with any of the other western Atlantic samples. These data suggest that Costa Rican tarpon could be partially isolated from other western Atlantic tarpon populations. Ultimately, international cooperation will be essential in the management of this species in both the eastern and western Atlantic Ocean.Communicated by P.W. Sammarco, Chauvin 相似文献
6.
Stock heterogeneity was investigated in albacore tuna (Thunnus alalunga, Bonnaterre 1788), a commercially important species in the North Atlantic Ocean and Mediterranean Sea. Twelve polymorphic
microsatellite loci were examined in 581 albacore tuna from nine locations, four in the north-east Atlantic Ocean (NEA), three
in the Mediterranean Sea (MED) and two in the south-western Pacific Ocean (SWP). Maximum numbers of alleles per locus ranged
from 9 to 38 (sample mean, 5.2–22.6 per locus; overall mean, 14.2 ± 0.47 SE), and observed heterozygosities per locus ranged
from 0.44 to 1.00 (overall mean: 0.79 ± 0.19 SE). Significant deficits of heterozygotes were observed in 20% of tests. Multilocus
F
ST values were observed ranging from 0.00 to Θ = 0.036 and Θ′ = 0.253, with a mean of Θ = 0.013 and Θ′ = 0.079. Pairwise F
ST values showed that the SWP, NEA and MED stocks were significantly distinct from one another, thus corroborating findings
in previous studies based on mitochondrial DNA, nuclear DNA (other than microsatellites) and allozyme analyses. Heterogeneity
was observed for the first time between samples within the Mediterranean Sea. GENELAND indicated the potential presence of
three populations across the NEA and two separate populations in the Mediterranean Sea. Observed genetic structure may be
related to migration patterns and timing of movements of subpopulations to the feeding grounds in either summer or autumn.
We suggest that a more intensive survey be conducted throughout the entire fishing season to ratify or refute the currently
accepted genetic homogeneity within the NEA albacore stock. 相似文献
7.
Megan E. Mach Elizabeth J. Sbrocco Lyndie A. Hice Tara A. Duffy David O. Conover Paul H. Barber 《Marine Biology》2011,158(3):515-530
The coastal marine environment of the Northwest Atlantic contains strong environmental gradients that create distinct marine
biogeographic provinces by limiting dispersal, recruitment, and survival. This region has also been subjected to numerous
Pleistocene glacial cycles, resulting in repeated extirpations and recolonizations in northern populations of marine organisms.
In this study, we examined patterns of genetic structure and historical demography in the Atlantic silverside, Menidia menidia, an annual marine fish with high dispersal potential but with well-documented patterns of clinal phenotypic adaptation along
the environmental gradients of the Northwest Atlantic. Contrary to previous studies indicating genetic homogeneity that should
preclude regional adaptation, results demonstrate subtle but significant (F
ST = 0.07; P < 0.0001) genetic structure among three phylogeographic regions that partially correspond with biogeographic provinces, suggesting
regional limits to gene flow. Tests for non-equilibrium population dynamics and latitudinal patterns in genetic diversity
indicate northward population expansion from a single southern refugium following the last glacial maximum, suggesting that
phylogeographic and phenotypic patterns have relatively recent origins. The recovery of phylogeographic structure and the
partial correspondence of these regions to recognized biogeographic provinces suggest that the environmental gradients that
shape biogeographic patterns in the Northwest Atlantic may also limit gene flow in M. menidia, creating phylogeographic structure and contributing to the creation of latitudinal phenotypic clines in this species. 相似文献
8.
The nurse shark, Ginglymostoma cirratum, inhabits shallow, tropical, and subtropical waters in the Atlantic and the eastern Pacific. Unlike many other species of
sharks, nurse sharks are remarkably sedentary. We assayed the mitochondrial control region and eight microsatellite loci from
individuals collected primarily in the western Atlantic to estimate the degree of population subdivision. Two individuals
from the eastern Atlantic and one from the Pacific coast of Panama also were genotyped. Overall, the mtDNA haplotype (h = 48 ± 5%) and nucleotide (π = 0.08 ± 0.06%) diversities were low. The microsatellite data mirror the mitochondrial results
with the average number of alleles ([`(N)]A \bar{N}_{A} = 9) and observed heterozygosity ([`(H)]O \bar{H}_{O} = 0.58) both low. The low levels of diversity seen in both the mtDNA and the microsatellite may be due to historical sea
level fluctuations and concomitant loss of shallow water habitat. Eight of the 10 pair-wise western Atlantic F
ST estimates for mtDNA indicated significant genetic subdivision. Pair-wise F
ST values for the microsatellite loci indicated a similar pattern as the mtDNA. The western Atlantic population of nurse sharks
is genetically subdivided with the strongest separation seen between the offshore islands and mainland Brazil, likely due
to deep water acting as a barrier to dispersal. The eastern and western Atlantic populations were closely related. The eastern
Pacific individual is quite different from Atlantic individuals and may be a cryptic, sister species. 相似文献
9.
The orange roughy Hoplostethus atlanticus is a well-known commercial species with a global distribution. There is no consensus about levels of connectivity among populations
despite a range of techniques having been applied. We used cytochrome c oxidase subunit I (COI) and cytochrome b sequences to study genetic connectivity at a global scale. Pairwise ΦST analyses revealed a lack of significant differentiation among samples from New Zealand, Australia, Namibia, and Chile. However,
low but significant differentiation (ΦST = 0.02–0.13, P < 0.05) was found between two Northeast Atlantic sites and all the other sites with COI. AMOVA and the haplotype genealogy
confirmed these results. The prevalent lack of genetic differentiation is probably due to active adult dispersal under the
stepping-stone model. Demographic analyses suggested the occurrence of two expansion events during the Pleistocene period. 相似文献
10.
The red porgy, Pagrus pagrus (L.), is a protogynous sparid associated with reefs and hard bottom habitat throughout the warm-temperate Atlantic Ocean.
In this study, the degree of geographic population differentiation in Atlantic populations was examined with microsatellite
and mitochondrial DNA markers (mtDNA). Six microsatellite loci were amplified and scored in 690 individuals from the eastern
North Atlantic (Crete, Madeira, and Azores), western North Atlantic (North Carolina to Florida, and the eastern Gulf of Mexico),
and Brazil. At two loci, fixed allelic differences were found among the three major geographic areas, while frequency differences
were observed at three other loci. The DNA of 371 individuals was amplified at the mtDNA control region, and 526 bp were sequenced.
Tamura–Nei’s D was used as a measure of nucleotide diversity and divergence: diversity averaged 0.011 within samples, while the corrected
divergence averaged 0 between samples within the same area and 0.061 between samples from different areas. Transversion haplotype
minimum spanning networks, nucleotide divergence, and F
ST values all show that the western Atlantic samples were more closely related to each other than any was to samples from the
eastern North Atlantic. Within the western North Atlantic, no significant population differentiation was observed, and within
the eastern North Atlantic, only the Azores sample showed detectable differences from Crete and Madeira. These data indicate
general homogeneity within large areas, and deep divisions between these areas.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
11.
The upwelling systems along the coast of Morocco support some of the largest populations of sardine (Sardina pilchardus) in the world. Although these populations provide a base for a substantial fishing industry, virtually nothing is known about
the genetic stock structure of this fish. Samples (n = 346), collected from seven sites along the Atlantic coast and in the Alboran Sea, were examined for exon-primed intron-crossing
PCR (EPIC-PCR) polymorphism. Two markers, CaM-4 and Ops-1, had 6 and 9 alleles, respectively, after the pooling of gel fragments
into 5 bp length classes, Correspondence analysis and the distribution of F
st among samples indicated that Moroccan populations were divided into two groups with F
st = 0.034 (P < 0.05) across the Gibraltar Strait. Populations along the Atlantic coast of Morocco comprise one genetic unit, except for
a weak genetic boundary south of Cape Ghir and the peculiar behavior of the Safi sample would indicate a genetic drift. Complex
ocean hydrodynamics around Gibraltar Strait and across Cape Ghir, likely, contributes to these genetic isolations. These results
point out the usefulness of population genetic studies in stock management for sardine populations that may be particularly
vulnerable to overexploitation especially during upwelling intensity shifts. 相似文献
12.
The patterns of genetic diversity and connectivity were investigated in Cucumaria frondosa, the most abundant sea cucumber in the North Atlantic, to assist in the management and conservation of this ecologically
important marine invertebrate, which is the target of an emerging fishery. Mitochondrial DNA COI sequences of 334 C. frondosa were obtained and analyzed, mainly from its western North Atlantic range, where the commercial fishery is being developed,
with complementary sampling in the mid- and eastern North Atlantic. Analysis of molecular variance showed no significant (P > 0.05) differences among subpopulations in the western region suggesting that it constitutes one panmictic population. The
same analysis showed low, but significant differences between eastern and western Atlantic populations. Coalescent analyses
using isolation with migration models and a Bayesian skyline plot indicated historical divergence and a general increase in
population size prior to the last glacial maximum and highly asymmetric gene flow (nearly 100 times lower from west to east)
between sea cucumbers from North America and Norway. Results suggest that subpopulations of C. frondosa within the western North Atlantic have been highly connected. We propose that aided by the high-connectivity local subpopulations
can recover rapidly from natural (i.e., ice ages) or anthropogenic (i.e., overfishing) population declines through recruitment
from deep refugia. 相似文献
13.
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
14.
Malia Chevolot Peter H. J. Wolfs Jónbjörn Pálsson Adriaan D. Rijnsdorp Wytze T. Stam Jeanine L. Olsen 《Marine Biology》2007,151(4):1275-1286
Population genetic structure of the thorny skate (Amblyraja radiata) was surveyed in >300 individuals sampled from Newfoundland, Iceland, Norway, the Kattegat and the central North Sea. A 290-bp
fragment of the mt cytochrome-b gene was first screened by SSCP. Sequences of SSCP haplotypes revealed 34 haplotypes, 14 of
which were unique to Iceland, 3 to Newfoundland, 1 to Norway and 3 to the Kattegat. The global F
ST was weak but significant. Removal of the two Kattegat locations, which were the most differentiated, resulted in no significant
genetic differentiation. Haplotype diversity was high and evenly distributed across the entire Atlantic (h = 0.8) with the exception of the North Sea (h = 0.48). Statistical parsimony revealed a star-like genealogy with a central widespread haplotype. A subsequent nested clade
analysis led to the inference of contiguous expansion with evidence for long distance dispersal between Newfoundland and Iceland.
Historical demographic analysis showed that thorny skates have undergone exponential population expansion that started between
1.1 million and 690,000 years ago; and that the Last Glacial Maximum apparently had little effect. These results strongly
differ from those of a parallel study of the thornback ray (Raja clavata) in which clear structure and former refugial areas could be identified. Although both species have similar life history
traits and overlapping ranges, the continental shelf edge apparently does not present a barrier to migration in A. radiata, as it does for R. clavata. 相似文献
15.
Vermilion snapper (Rhomboplites aurorubens) were collected from four sites off the Atlantic coast of the USA and one site in the Gulf of Mexico to evaluate effective
population size and genetic stock structure. Previous studies had suggested geographic variation in the ratio of males to
females, so this population characteristic was explored in conjunction with the genetic analysis. Sex ratio varied greatly
among the five sample sites; males comprised 57% of samples in the Gulf of Mexico, while within the South Atlantic Bight they
comprised between 36% (Morehead City, North Carolina) and 53% (Carolina Beach, North Carolina) of samples. No clear geographic
trends in the sex ratio emerged; instead, it was found to vary with fish length, the percentage of males decreasing with increasing
size. Allelic variation assessed at seven dinucleotide microsatellite loci was large; gene diversities ranged from 0.43 to
0.95 and allelic counts from 7 to 39. Estimates of the effective population size ranged from 24 500 (based on the infinite-alleles
model) to 150 500 (based on the stepwise-mutation model). There was evidence for excess homozygosity within samples: estimates
of F
IS
(the correlation of alleles within individuals) ranged from 0.01 to 0.03 among the seven loci, and three estimates were significantly
greater than zero. Differentiation among localities was very weak, as estimates of F
ST
(the correlation of alleles within populations) were on the order of 0.001 to 0.002 and genetic distance estimates between
localities were not related to geographic distances. This suggested that vermilion snapper in the South Atlantic Bight (Cape
Hatteras, North Carolina to Cape Canaveral, Florida) and Gulf of Mexico are likely to consist of one genetic stock. Despite
the overall homogeneity, there were indications of a temporally dynamic local structure that would bear further examination.
Received: 6 July 1998 / Accepted: 9 February 1999 相似文献
16.
Genetic diversity among four natural samples of Blackspot seabream (Pagellus bogaraveo, Brünnich, 1768) from different fishing grounds exploited by Spanish fisheries was analyzed through the use of 12 microsatellite
markers. The samples were captured off the Spanish coasts from the Mediterranean Sea to the Cantabrian Sea within the same
continental slope. High levels of genetic diversity were revealed for every population and every locus was polymorphic at
the 0.95 level. The average number of alleles, average heterozygosity and PIC were found to be 15.75, 0.833 and 0.818, respectively.
In general, population differentiation was not detected in these samples. Through AMOVA, a low level of variation between
regions (Mediterranean vs. Atlantic samples) was observed, though this was not significant. A larger percentage of total variation
was observed inside the ‘within populations’ class. Thus, AMOVA did not reveal any significant population substructure. Moreover,
no correlation was found between geographical and FST estimates and the observed results did not allow the improvement of a model of isolation by distance. The high homogeneity
revealed by means of these markers could indicate the absence of physical frontiers between the geographical areas analyzed
in this survey, especially between Atlantic and Mediterranean areas. 相似文献
17.
Nicole M. Phillips Jennifer A. Chaplin David L. Morgan Stirling C. Peverell 《Marine Biology》2011,158(4):903-915
Northern Australia is considered to be one of the last strongholds for three critically endangered sawfishes, Pristis zijsron, Pristis clavata, and Pristis microdon, making these populations of global significance. Population structure and levels of genetic diversity were assessed for
each species across northern Australia using a portion of the mitochondrial control region. Statistically significant genetic
structure was detected in all three species, although it was higher in P. microdon (F
ST = 0.811; N = 149) than in either P. clavata (F
ST = 0.419; N = 73) or P. zijsron (F
ST = 0.202; N = 49), possibly due to a much higher and/or localized level of female philopatry in P. microdon. The overall levels of haplotype diversity in P. zijsron (h = 0.555), P. clavata (h = 0.489), and P. microdon (h = 0.650) were moderate, although it appears to be reduced in the assemblages of P. zijsron and P. clavata in the Gulf of Carpentaria (h = 0.342 and h = 0.083, respectively). Since female migration (replenishment) between regions is unlikely, conservation plans should strive
to maintain current levels of diversity and abundances in the regional assemblages of each species. 相似文献
18.
The distribution and genetic structure of many marine invertebrates in the North Atlantic have been influenced by the Pleistocene glaciation, which caused local extinctions followed by recolonization in warmer periods. Mitochondrial DNA markers are typically used to reconstruct species histories. Here, two mitochondrial markers [16S rDNA and cytochrome c oxidase I (COI)] were used to study the evolution of the widely distributed hydrozoan Obelia geniculata (Linnaeus, 1758) from the North Atlantic and the Pacific and, more specifically, in the context of North Atlantic phylogeography. Samples were collected from six geographic localities between 1998 and 2002. Hydroids from the North Atlantic, North Pacific (Japan), and South Pacific (New Zealand) are reciprocally monophyletic and may represent cryptic species. Using portions of the 16S rDNA and COI genes and the date of the last trans-Arctic interchange (3.1–4.1 million years ago), the first calibrated rate of nucleotide substitutions in hydrozoans is presented. Whereas extremely low substitution rates have been reported in other cnidarians, mainly based on anthozoans, substitution rates in O. geniculata are comparable to other invertebrates. Despite a life history that ostensibly permits substantial dispersal, there is apparently considerable genetic differentiation in O. geniculata. Divergence estimates and the presence of unique haplotypes provide evidence for glacial refugia in Iceland and New Brunswick, Canada. A population in Massachusetts, USA, appears to represent a relatively recent colonization event.Communicated by J.P. Grassle, New Brunswick 相似文献
19.
Prevailing oceanographic processes, pelagic larvae, adult mobility, and large populations of many marine species often leads
to the assumption of wide-ranging populations. Applying this assumption to more localized populations can lead to inappropriate
conservation measures. The Pacific ocean perch (Sebastes alutus, POP) is economically and ecologically valuable, but little is known about its population structure and life history in Alaskan
waters. Fourteen microsatellite loci were used to characterize geographic structure and connectivity of POP collections (1999–2005)
sampled along the continental shelf break from Dixon Entrance to the Bering Sea. Despite opportunities for dispersal, there
was significant, geographically related genetic structure (F
ST = 0.0123, P < 10−5). Adults appear to belong to neighborhoods at geographic scales less than 400 km, and possibly as small as 70 km, which indicates
limited dispersal throughout their lives. The population structure observed has a finer geographic scale than current management,
which suggests that measures for POP fisheries conservation should be revisited. 相似文献
20.
Gretchen Goodbody-Gringley Steven V. Vollmer Robert M. Woollacott Gonzalo Giribet 《Marine Biology》2010,157(12):2591-2602
Understanding population connectivity in corals is particularly important as these organisms are increasingly threatened by
abiotic and biotic factors. This study examined the population genetic structure of the brooding coral Favia fragum across four locations in the Caribbean and Western Atlantic using mitochondrial and nuclear markers. Morphological features
were also compared to test whether genetic diversity corresponds with skeletal morphology. When comparing across distantly
related Caribbean and Bermudian locations, F
ST values were high and significant, indicating strong genetic structure. At a local scale, significant genetic structure was
found among reefs in Panama, while no genetic structure was found among reefs within Barbados, Bermuda or Jamaica. Surprisingly,
a single haplotype for each of the three markers examined was found in Bermuda, where samples varied significantly from all
other locations in three out of four morphological features analyzed. These data indicate that gene flow of F. fragum may occur locally among reefs but is highly restricted at distant locations. Furthermore, isolated populations, such as that
of Bermuda, must be self-seeding to maintain the observed genetic uniformity. 相似文献