scholarly journals Haplotype distribution and connectivity of the white sea urchin Tripneustes ventricosus across the Brazilian biogeographic province

2016 ◽  
Author(s):  
Wander O Godinho ◽  
Rodrigo Maggioni ◽  
Ana L Lacerda ◽  
Tito M C Lotufo
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Sea Urchin ◽  
White Sea ◽  
Sea Urchins ◽  
Marine Ecosystems ◽  
Brazilian Coast ◽  
The White Sea ◽  
Biogeographic Province ◽  
Fernando De Noronha

Sea urchins play important roles in marine ecosystems as key herbivores and some species have wide geographic range. The Atlantic white sea urchin Tripneustes ventricosus is abundant in many rock reefs of the eastern and western Atlantic, and may be found in high densities in Atolls and Archipelagos. Despite the importance of sea urchins in insular ecosystems, there is no study evaluating the genetic structure and the origin of the white sea urchin in isolated ecosystems. Such information is crucial to understand the connectivity and genetic diversity of these populations from the tropical Atlantic provinces. To evaluate the origin of the white sea urchin in Fernando de Noronha Archipelago and the genetic features of this population, we conducted studies on the population structure of the white sea urchin using mitochondrial DNA (COI), in two regions within the Brazilian biogeographic province and compared with other regions in the Atlantic. The white sea urchin from Fernando de Noronha was found to be genetically distinct, with FST ranging from 0.3 to 0.9 from other populations in Atlantic. The sharing of haplotypes between the Brazilian coast and the archipelago suggests that insular species derived from the Brazilian coast, rather than the East Atlantic. Moreover, all other Atlantic populations were genetically isolated, with low genetic diversity being a common characteristic among them (ranging from 0.0011 to 0.0022). The low connectivity found within populations might be related to the presence of soft barriers among the Brazilian biogeographic province. The low nucleotide diversity may also suggest that T. ventricosus may have undergone bottleneck processes at some stage of their evolution. This study has important implications on the geographic distribution, population structure and gene flow of the white sea urchin among the Atlantic regions. Further studies should evaluate the biological and ecological aspects of the species in both insular and continental marine ecosystems.

scholarly journals Haplotype distribution and connectivity of the white sea urchin Tripneustes ventricosus across the Brazilian biogeographic province

2016 ◽  
Author(s):  
Wander O Godinho ◽  
Rodrigo Maggioni ◽  
Ana L Lacerda ◽  
Tito M C Lotufo
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Sea Urchin ◽  
White Sea ◽  
Sea Urchins ◽  
Marine Ecosystems ◽  
Brazilian Coast ◽  
The White Sea ◽  
Biogeographic Province ◽  
Fernando De Noronha

Sea urchins play important roles in marine ecosystems as key herbivores and some species have wide geographic range. The Atlantic white sea urchin Tripneustes ventricosus is abundant in many rock reefs of the eastern and western Atlantic, and may be found in high densities in Atolls and Archipelagos. Despite the importance of sea urchins in insular ecosystems, there is no study evaluating the genetic structure and the origin of the white sea urchin in isolated ecosystems. Such information is crucial to understand the connectivity and genetic diversity of these populations from the tropical Atlantic provinces. To evaluate the origin of the white sea urchin in Fernando de Noronha Archipelago and the genetic features of this population, we conducted studies on the population structure of the white sea urchin using mitochondrial DNA (COI), in two regions within the Brazilian biogeographic province and compared with other regions in the Atlantic. The white sea urchin from Fernando de Noronha was found to be genetically distinct, with FST ranging from 0.3 to 0.9 from other populations in Atlantic. The sharing of haplotypes between the Brazilian coast and the archipelago suggests that insular species derived from the Brazilian coast, rather than the East Atlantic. Moreover, all other Atlantic populations were genetically isolated, with low genetic diversity being a common characteristic among them (ranging from 0.0011 to 0.0022). The low connectivity found within populations might be related to the presence of soft barriers among the Brazilian biogeographic province. The low nucleotide diversity may also suggest that T. ventricosus may have undergone bottleneck processes at some stage of their evolution. This study has important implications on the geographic distribution, population structure and gene flow of the white sea urchin among the Atlantic regions. Further studies should evaluate the biological and ecological aspects of the species in both insular and continental marine ecosystems.

Genetic diversity and population structure of the commercially harvested sea urchin Paracentrotus lividus (Echinodermata, Echinoidea)

2004 ◽  
Vol 13 (11) ◽  
pp. 3317-3328 ◽  
Author(s):  
SANDRA DURAN ◽  
CRUZ PALACÍN ◽  
MIKEL A. BECERRO ◽  
XAVIER TURON ◽  
GONZALO GIRIBET
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Sea Urchin ◽  
Paracentrotus Lividus

scholarly journals Population connectivity and larval dispersal of the exploited mangrove crab Ucides cordatus along the Brazilian coast

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4702 ◽  
Author(s):  
Fábio B. Britto ◽  
Anders J. Schmidt ◽  
Adriana M.F. Carvalho ◽  
Carolina C.M.P. Vasconcelos ◽  
Antonia M. Farias ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Gene Flow ◽  
Population Connectivity ◽  
Brazilian Coast ◽  
Fishery Resource ◽  
Ucides Cordatus ◽  
Migration Rates ◽  
Mangrove Crab ◽  
Key Species

Background The mangrove crab Ucides cordatus is considered a key species for the ecological balance of mangrove forests and a major source of employment and income for traditional crab collectors in Brazil. Several studies evidenced weak genetic variation among populations due to an efficient larval transport. However, gene flow patterns of the species is poorly understood, with no information about migration rates. The influence of the two main Brazilian currents in larval dispersion is also not clear. In order to provide baseline information for conservation, planning and management of this important fishery resource, the present study aimed to estimate and evaluate spatial distribution of genetic diversity, migration rates and gene flow directivity among populations of U. cordatus in Brazil. Methods Nine microsatellites were used to resolve population structure of 319 crabs collected from six sites located along the Brazilian coast. The degree of geographical differentiation included estimates of genetic diversity, population structure and gene flow models, with spatial analysis of shared alleles (SAShA), isolation by distance tests, AMOVA, discriminant analysis of principal components (DAPC) and Bayesian clustering. We estimated the amount of ongoing gene flow between clusters using the coalescent-based method implemented in Migrate-N. Results Loci were highly polymorphic (average of 12.4 alleles per locus) evidencing high genetic variability. There was significant differentiation among localities, despite of the low value of FST (= 0.019; P < 0.001). FST and Jost’s D indexes were also estimated in pairwise comparisons and showed significant differences between most of the surveyed site pairs (P < 0.05). Structure evidenced a single genetic group among samples, however SAShA pointed to a non-panmictic condition (P = 0.011). AMOVA detected four statistical significant clusters with low level of differentiation (FCT = 0.037; P = 0.023). The gene flow model that best described the population connectivity was the island model, with ∼24 crabs being exchanged among localities per generation. Discussion The high migration rates found among localities seem to be the main force acting to sustain the distribution of the genetic diversity of U. cordatus. Despite the high gene flow and the weak population structure among samples, the significant genetic differences found suggest that gene flow alone does not bypass the effects of genetic drift, natural selection and/or human exploitation. These findings are vital for the establishment of a database to be used in the development of conservation programs.

scholarly journals Feeding-deterrent properties of diterpenes of Dictyota mertensii (Phaeophyceae, Dictyotales)

2007 ◽  
Vol 55 (3) ◽  
pp. 223-229 ◽  
Author(s):  
Magui Aparecida Vallim ◽  
Valéria Laneuville Teixeira ◽  
Renato Crespo Pereira
Keyword(s):  
Secondary Metabolites ◽  
Sea Urchin ◽  
Brown Seaweed ◽  
Brazilian Coast ◽  
Lytechinus Variegatus ◽  
Minor Components ◽  
Active Fraction ◽  
Ecological Specialization ◽  
Fernando De Noronha ◽  
Different Populations

Crude extracts of the brown seaweed Dictyota mertensii (Martius) Kützing collected at two distant and different places on the Brazilian coast, Búzios (Rio de Janeiro) and Fernando de Noronha (PE), were evaluated for defensive chemistry against the crab Pachygrapsus transversus, and the sea urchin Lytechinus variegatus. The extract from Búzios specimens of D. mertensii significantly inhibited the consumption by both P. transversus and L. varigetaus. Fractionation of the extracts of specimens of D. mertensii from Búzios and F. de Noronha followed by complementary assays revealed one active fraction from each location, which contained distinct defensive secondary metabolites. In each active fractions prenylated guaiane diterpenes were the major compounds. Dictyol H and epoxypachydictyol A were the most abundant compounds in Búzios and F. de Noronha, respectively, followed by minor components. Our results show a differential production of secondary metabolites in the two distant and different populations of D. mertensii along the Brazilian coast. This suggests that defensive chemicals from this seaweed are not qualitatively absolute characteristics of the species, but may represent an ecological specialization to successfully prevent herbivory.

scholarly journals The state of gene pool of the basic forest-forming species of the white sea watershed (on the example of a Picea × fennica (Regel) kom. And Pinus sylvestris L.)

2020 ◽  
Vol 18 (2) ◽  
pp. 185-202
Author(s):  
Aleksey A. Ilinov ◽  
Boris V. Raevsky ◽  
Olga V. Chirva
Keyword(s):  
Climate Change ◽  
Genetic Diversity ◽  
Global Climate Change ◽  
White Sea ◽  
Global Climate ◽  
The State ◽  
The Arctic ◽  
The White Sea ◽  
Negative Effects ◽  
Scotch Pine

Background. The genetic diversity of forest tree species populations is a key factor contributing to their resistance against negative effects of human activity, and the global climate change. The aim of the present study was to evaluate the state of gene pools of the main forest-forming species in the White Sea watershed. Materials and methods. Five populations of Norway spruce and seven populations of Scotch pine have been selected within the Arctic zone of the European part of Russia (the western part of the White Sea watershed), along with two boundary ones located near the northern borders of the abovementioned species areas. The analysis of the spruce samples had been performed using five nuclear SSR loci, while for the pine samples it was four. DNA fragments were separated on a sequencer CEQ 8000. The main criteria of the genetic diversity (A99%, Ho, He) and F-statistics were calculated. Results. The marginal spruce populations were characterized by the largest magnitude of the genetic diversity (Ho = 0.46; He = 0.47) and isolation (FST = 0.33) compared to other populations of the same species. The differences were statistically significant. All pine populations studied demonstrated a higher level of genetic diversity (Ho = 0.50, He = 0.63) compared to spruce populations. The differences between the boundary and in-area populations were not statistically reliable (FST = 0.04). Conclusion. Our investigation revealed a sufficiently high level of spruce and pine northern populations genetic diversity making them able to withstand expected negative effects of anthropogenic activity and global climate change.

scholarly journals Spatio-temporal patterns based on demographic and genetic diversity of the purple sea urchin Paracentrotus lividus in the area around Corsica (Mediterranean Sea)

2018 ◽  
Vol 19 (3) ◽  
pp. 620 ◽  
Author(s):  
SOPHIE DUCHAUD ◽  
ERIC D.H. DURIEUX ◽  
STEPHANE COUPE ◽  
VANINA PASQUALINI ◽  
SONIA TERNENGO
Keyword(s):  
Genetic Diversity ◽  
Sea Urchin ◽  
Sea Urchins ◽  
Paracentrotus Lividus ◽  
Population Densities ◽  
Genetic Structuring ◽  
High Genetic Diversity ◽  
Size Classes ◽  
Purple Sea Urchin ◽  
Spatio Temporal

Sea urchins were harvested for decades in many areas throughout its distribution range, potentially leading to population collapse. In France, the purple sea urchin Paracentrotus lividus is intensively harvested. Yet, the demography and population dynamics remained under-documented, particularly in Corsica. In this context, we have characterized the fluctuations in density of several size classes at 8 sites around the island, and assessed the genetic diversity and structuring of the population. Densities recorded lie between 0 and 2.18 (± 0.41) individuals.m-2 and spatio-temporal variabilities have also been highlighted. The study of the influence of vegetation cover on the size classes suggests that small- and medium- sized individuals prefer substrates of intermediate heights, whereas individuals with a diameter ≥ 5 cm are more often observed on encrusting substrates, and may be responsible for the continuation of this type of benthic community. The genetic study indicates a high genetic diversity with a low genetic structuring. The Ne values obtained are similar to those described in previous papers. Due to estimates of local contemporary Ne and the homogeneous genetic diversity, our data tend to show that the Corsican population of P. lividus is not overexploited.

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