scholarly journals Dispersal ability, habitat characteristics, and sea-surface circulation shape population structure of Cingula trifasciata (Gastropoda: Rissoidae) in the remote Azores Archipelago

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
L. Baptista ◽  
H. Meimberg ◽  
S. P. Ávila ◽  
A. M. Santos ◽  
M. Curto
Keyword(s):  
Population Dynamics ◽  
Population Structure ◽  
Gene Flow ◽  
Atlantic Ocean ◽  
Marine Invertebrates ◽  
Sea Surface ◽  
Dispersal Ability ◽  
Azores Archipelago ◽  
Surface Circulation ◽  
Northeast Atlantic Ocean

Abstract Background In the marine realm, dispersal ability is among the major factors shaping the distribution of species. In the Northeast Atlantic Ocean, the Azores Archipelago is home to a multitude of marine invertebrates which, despite their dispersal limitations, maintain gene flow among distant populations, with complex evolutionary and biogeographic implications. The mechanisms and factors underlying the population dynamics and genetic structure of non-planktotrophic gastropods within the Azores Archipelago and related mainland populations are still poorly understood. The rissoid Cingula trifasciata is herewith studied to clarify its population structure in the Northeast Atlantic Ocean and factors shaping it, with a special focus in intra-archipelagic dynamics. Results Coupling microsatellite genotyping by amplicon sequencing (SSR-GBAS) and mitochondrial datasets, our results suggest the differentiation between insular and continental populations of Cingula trifasciata, supporting previously raised classification issues and detecting potential cryptic diversity. The finding of connectivity between widely separated populations was startling. In unique ways, dispersal ability, habitat type, and small-scale oceanographic currents appear to be the key drivers of C. trifasciata’s population structure in the remote Azores Archipelago. Dispersal as non-planktotrophic larvae is unlikely, but its small-size adults easily engage in rafting. Although the typical habitat of C. trifasciata, with low hydrodynamics, reduces the likelihood of rafting, individuals inhabiting algal mats are more prone to dispersal. Sea-surface circulation might create dispersal pathways for rafts, even between widely separated populations/islands. Conclusions Our results show that gene flow of a marine non-planktotrophic gastropod within a remote archipelago can reveal unanticipated patterns, such that the understanding of life in such areas is far from well-understood. We expect this work to be the starting of the application of SSR-GBAS in other non-model marine invertebrates, providing insights on their population dynamics at distinct geographical scales and on hidden diversity. How transversal is the role played by the complex interaction between functional traits, ecological features, and sea-surface circulation in the population structure of marine invertebrates can be further addressed by expanding this approach to more taxa.

A temporal perspective on population structure and gene flow in Atlantic salmon (Salmo salar) in Newfoundland, Canada

2010 ◽  
Vol 67 (2) ◽  
pp. 225-242 ◽  
Author(s):  
Friso P. Palstra ◽  
Daniel E. Ruzzante
Keyword(s):  
Population Dynamics ◽  
Population Structure ◽  
Gene Flow ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Environmental Changes ◽  
Population Connectivity ◽  
Temporal Perspective ◽  
Atlantic Salmon Salmo Salar ◽  
Contemporary Gene Flow

Studying population structure and gene flow patterns on temporal scales facilitates an evaluation of the consequences of demographic, physical, and environmental changes on the stability and persistence of populations. Here, we examine temporal genetic variation within and among Atlantic salmon ( Salmo salar ) rivers in Newfoundland and Labrador, Canada, using samples collected over a period of six decades (1951–2004). Our objective was to evaluate temporal changes in population connectivity associated with the closure of a commercial marine fishery. Despite demographic instability, we find that population structure remained temporally stable over more than 50 years. However, age structure can affect results when not taken into consideration, particularly in populations of large effective size where genetic drift is not strong. Where weak signals of genetic differentiation did not complicate analyses, contemporary migration was often asymmetric, yet low, suggesting patterns of intermittent gene flow. Nevertheless, we find some links between changes in population dynamics and contemporary gene flow. These findings may therefore imply that management decisions impacting the contemporary population dynamics of individual Atlantic salmon rivers can also affect the genetic stability of this species as a whole.

scholarly journals Genetic population structure of the blue sea star Linckia laevigata in the Visayas (Philippines)

2015 ◽  
pp. 1-7 ◽  
Author(s):  
Diana Sr Alcazar ◽  
Marc Kochzius
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Gene Flow ◽  
Comparative Analysis ◽  
Marine Invertebrates ◽  
Genetic Population Structure ◽  
Sea Star ◽  
Genetic Population ◽  
Gene Coi ◽  
Linckia Laevigata

Coral reef associated marine invertebrates, such as the blue sea starLinckia laevigata, have a life history with two phases: sedentary adults and planktonic larvae. On the one hand it is hypothesised that the long pelagic larval duration facilitates large distance dispersal. On the other hand, complex oceanographic and geographic characteristics of the Visayan seascape could cause isolation of populations. The study aims to investigate the genetic diversity, genetic population structure and gene flow inL. laevigatato reveal connectivity among populations in the Visayas. The analysis is based on partial sequences (626 bp in length) of the mitochondrial cytochrome oxidase I gene (COI) from 124 individuals collected from five localities in the Visayas. A comparative analysis of these populations with populations from the Indo-Malay Archipelago (IMA) published previously is also presented. Genetic diversity was high (h = 0.98, π = 1.6%) and comparable with preceding studies. Analyses of molecular variance (AMOVA) revealed a lack of spatial population differentiation among sample sites in the Visayas (ΦST-value = 0.009;P > 0.05). The lack of genetic population structure indicates high gene flow among populations ofL. laevigatain the Visayas. Comparative analysis with data from the previous study indicates high connectivity of the Visayas with the central part of the IMA.

scholarly journals Genetic population structure of European anchovy in the Mediterranean Sea and the Northeast Atlantic Ocean using sequence analysis of the mitochondrial DNA control region

2013 ◽  
Vol 71 (2) ◽  
pp. 391-397 ◽  
Author(s):  
Jordi Viñas ◽  
Núria Sanz ◽  
Luis Peñarrubia ◽  
Rosa-Maria Araguas ◽  
José-Luis García-Marín ◽  
...  
Keyword(s):  
Population Structure ◽  
Atlantic Ocean ◽  
Mediterranean Sea ◽  
Control Region ◽  
Genetic Population ◽  
Mitochondrial Dna Control Region ◽  
European Anchovy ◽  
Northeast Atlantic ◽  
Northeast Atlantic Ocean ◽  
The Mediterranean

Abstract Viñas, J., Sanz, N., Peñarrubia, L., Araguas, R-M., García-Marín, J-L., Roldán, M-I., and Pla, C. 2014. Genetic population structure of European anchovy in the Mediterranean Sea and the Northeast Atlantic Ocean using sequence analysis of the mitochondrial DNA control region. – ICES Journal of Marine Science, 71: 391–397. The European anchovy (Engraulis encrasicolus) exhibits a complex population structure in the Mediterranean Sea and Northeast Atlantic Ocean. To resolve the population genetic structure of this species, we surveyed sequence variability in the mitochondrial (mtDNA) control region in samples (n = 563) from 13 locations in the Northeast Atlantic, the Bay of Biscay, and the Mediterranean Sea. Based on pairwise ΦSTs, SAMOVA, and multidimensional scaling, a complicated population structure composed of multiple populations emerged. Combining these results with those from previous population studies based on mitochondrial and nuclear markers, we identified nine genetically differentiated European anchovy populations: (i) Canary Islands; (ii) Cádiz; (iii) Alborán Sea; (iv) Garona; (v) Arcachon and Donostia; (vi) a large population in the northwestern Mediterranean, including Cadaqués, Gulf of Lyon, Elba, and Sicily; (vii) southern Adriatic; (viii) northern Adriatic; and (ix) Aegean Sea. We suggest that independent management strategies should be implemented for each genetically differentiated population, and, in cases where several fisheries stocks are recognized within an area of genetic homogeneity, each stock should be managed separately.

Population structure and movement patterns of blackbelly rosefish in the NE Atlantic Ocean (Azores archipelago)

2020 ◽  
Vol 29 (3) ◽  
pp. 227-237 ◽  
Author(s):  
Régis Santos ◽  
Ana Pabon ◽  
Wendell Silva ◽  
Hélder Silva ◽  
Mário Pinho
Keyword(s):  
Population Structure ◽  
Atlantic Ocean ◽  
Movement Patterns ◽  
Ne Atlantic ◽  
Azores Archipelago ◽  
Ne Atlantic Ocean

scholarly journals Population structure in the Andaman keelback, Xenochrophis tytleri: geographical distance and oceanic barriers to dispersal influence genetic divergence on the Andaman archipelago

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5752 ◽  
Author(s):  
Ashwini Venkatanarayana Mohan ◽  
Priyanka Swamy ◽  
Kartik Shanker
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Spatial Data ◽  
Isolation By Distance ◽  
Structured Populations ◽  
Dispersal Ability ◽  
Geographical Distance ◽  
Anthropogenic Stress ◽  
Positive Correlation ◽  
Continental Islands

Limited gene flow between populations due to geographic distance, presence of barriers or inherent low dispersal ability leads to the formation of genetically structured populations. Strong population structure indicates lowered levels or absence of gene flow which might lead to inbreeding and loss of genetic capacity to recuperate from anthropogenic stress and natural calamities. Terrestrial reptiles are generally known to have low dispersal abilities and few studies have explored drivers of their population structure on continental islands, where both anthropogenic stress and natural calamities are relatively common. We investigated the population structure and drivers of diversification of the Andaman keelback (Xenochrophis tytleri), an endemic, terrestrial and freshwater snake species in the Andaman archipelago, a continental group of islands in the Bay of Bengal. Data was collected from 86 individuals from seven islands and 78 individuals were sequenced for the gene Nuclear Dehydrogenase subunit 4 to identify the number of populations and distribution of genetic diversity across populations. We found 11 haplotypes on seven islands and observed high genetic differentiation between seven populations defined island-wise (FST = 0.82). We further tested the number of populations by incorporating spatial data into Bayesian Clustering Analysis (GENELAND) and identified six populations of the Andaman keelback. We tested for the influence of Isolation-by-distance on these populations. While the overall trend showed a positive correlation between geographic and genetic distance, a correlogram revealed that the positive correlation disappears beyond ∼20–40 km. We also tested for the presence of geographical barriers to gene flow using Monmonier’s algorithm (SPADS), which identified five barriers to dispersal confirming that there are oceanic barriers to dispersal for some island populations of the Andaman keelback. As the Andaman Islands are arranged almost in a straight line from North to South, our data are insufficient to tease apart the roles of geographical distance and barriers to gene flow. We conclude that salt waters between near islands are weak barriers and as the geographical distance between islands increases, so does the strength of the barrier.

Differentiation and Interrelations of Two Representatives of Laudakia stellio Complex (Reptilia: Agamidae) in Israel

2011 ◽  
Vol 4 (2) ◽  
pp. 102-114 ◽  
Author(s):  
Evgenyi N. Panov ◽  
Larissa Yu. Zykova
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Habitat Preference ◽  
Additional Data ◽  
Near East ◽  
Field Studies ◽  
Subspecies Level ◽  
Limited Gene Flow ◽  
Study Sites ◽  
And Behavior

Field studies were conducted in Central Negev within the breeding range of Laudakia stellio brachydactyla and in NE Israel (Qyriat Shemona) in the range of an unnamed form (tentatively “Near-East Rock Agama”), during March – May 1996. Additional data have been collected in Jerusalem at a distance of ca. 110 km from the first and about 170 km from the second study sites. A total of 63 individuals were caught and examined. The animals were marked and their subsequent movements were followed. Social and signal behavior of both forms were described and compared. Lizards from Negev and Qyriat Shemona differ from each other sharply in external morphology, habitat preference, population structure, and behavior. The differences obviously exceed the subspecies level. At the same time, the lizards from Jerusalem tend to be intermediate morphologically between those from both above-named localities, which permits admitting the existence of a limited gene flow between lizard populations of Negev and northern Israel. The lizards from NE Israel apparently do not belong to the nominate subspecies of L. stellio and should be regarded as one more subspecies within the species.

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