Mostrando recursos 1 - 20 de 26

  1. Genetic considerations on the introduction of farmed fish in marine protected areas: The case of study of white seabream restocking in the Gulf of Castellammare (Southern Tyrrhenian Sea)

    Gonzalez-Wangueemert, Mercedes; Fernandez, Tomas Vega; Perez-Ruzafa, Angel; Giacalone, Maximilian; D'Anna, Giovanni; Badalamenti, Fabio
    Human exploitation has drastically reduced the abundance and distribution of several marine fish and invertebrate populations through overfishing and habitat destruction. Restocking can potentially mitigate these impacts and help to reconstitute depleted stocks but genetic repercussions must be considered. In the present study, the degree of genetic similarity between white seabream (Diplodus sargus Linnaeus 1758) individuals reared for restocking purposes and the receiving population in the Gulf of Castellammare fishery reserve (Sicily, Italy) was assessed using microsatellites. We also inferred the spatial pattern of the genetic structure of D. sargus and connectivity along Sicilian coasts. The farmed population showed significant heterozygosity deficiency in 6 loci and an...

  2. Genetic diversity across geographical scales in marine coastal ecosystems: Holothuria arguinensis a model species

    Rodrigues, F.; Valente, Sara; Gonzalez-Wanguemert, M.
    Coastal lagoons are considered one of the most productive areas of our planet harboring a large variety of habitats. Their transitional character, between terrestrial and marine environments, creates a very particular ecosystem with important variations of its environmental conditions. The organisms that are able to survive on these ecosystems frequently experience strong selective pressures and constrictions to gene flowwith marine populations, which could contribute to genetic divergence among populations inhabiting coastal lagoon and marine environments. Therefore, the main aims of this study are to asses the genetic diversity and population structure of Holothuria arguinensis across geographical ranges, to test the hypothesis of coastal lagoons as hotspots...

  3. Connectivity patterns inferred from the genetic structure of white seabream (Diplodus sargus L.)

    Gonzalez-Wangueemert, M.; Canovas, F.; Perez-Ruzafa, A.; Marcos, C.; Alexandrino, P.
    Themarine environment seems, at first sight, to be a homogeneousmediumlacking barriers to species dispersal. Nevertheless, populations of marine species show varying levels of gene flow and population differentiation, so barriers to gene flow can often be detected. Weaimto elucidate the role of oceanographical factors ingenerating connectivity among populations shaping the phylogeographical patterns in the marine realm, which is not only a topic of considerable interest for understanding the evolution ofmarine biodiversity but also formanagement and conservation of marine life. For this proposal,we investigate the genetic structure and connectivity between continental and insular populations ofwhite seabreamin North East Atlantic (NEA) and Mediterranean Sea (MS) aswell as the influence...

  4. Population genetics of Cerastoderma edule in Ria Formosa (southern Portugal): the challenge of understanding an intraspecific hotspot of genetic diversity

    Vergara-Chen, Carlos; Rodrigues, Fernanda; Gonzalez-Wangueemert, Mercedes
    Coastal lagoons are highly variable environments that may act as hotspots of genetic diversity as a consequence of their ecological role as nursery habitats of marine species with both ecological and fisheries importance. The edible cockle (Cerastoderma edule) is a commercially important shellfish resource inhabiting coastal lagoons in Europe and their fisheries management urgently needs genetic studies to design appropriate strategies to promote the recovery of exploited populations. The aim of this study was to assess the C. edule genetic diversity and population structure at a small geographic scale, inside Ria Formosa coastal lagoon (southern Portugal) using mitochondrial cytochrome oxidase I sequences in six locations. Outcomes...

  5. Phylogeography of the Atlanto-Mediterranean sea cucumber Holothuria (Holothuria) mammata: the combined effects of historical processes and current oceanographical pattern

    Borrero-Perez, G. H.; Gonzalez-Wangueemert, M.; Marcos, C.; Perez-Ruzafa, A.
    We assessed the genetic structure of populations of the widely distributed sea cucumber Holothuria (Holothuria) mammata Grube, 1840, and investigated the effects of marine barriers to gene flow and historical processes. Several potential genetic breaks were considered, which would separate the Atlantic and Mediterranean basins, the isolated Macaronesian Islands from the other locations analysed, and the Western Mediterranean and Aegean Sea (Eastern Mediterranean). We analysed mitochondrial 16S and COI gene sequences from 177 individuals from four Atlantic locations and four Mediterranean locations. Haplotype diversity was high (H = 0.9307 for 16S and 0.9203 for COI), and the haplotypes were closely related (p = 0.0058 for 16S and 0.0071...

  6. Small-scale genetic structure of Cerastoderma glaucum in a lagoonal environment: potential significance of habitat discontinuity and unstable population dynamics

    Vergara-Chen, Carlos; Gonzalez-Wangueemert, Mercedes; Marcos, Concepcion; Perez-Ruzafa, Angel
    Environmental heterogeneity in coastal lagoons is expected to facilitate local adaptation in response to different ecological conditions, causing significant genetic structuring within lagoon populations at a small scale and also differentiation between lagoons. However, these patterns and processes of genetic structuring are still poorly understood. The aims of our study were (1) to seek genetic structure at a small scale in Cerastoderma glaucum inside the Mar Menor coastal lagoon using a mitochondrial DNA marker (COI) that has previously detected genetic differentiation inside the lagoon in other species and (2) to evaluate the influence of extreme environmental conditions and habitat discontinuity on its genetic composition. The results indicate...

  7. Do hatchery-reared sea urchins pose a threat to genetic diversity in wild populations?

    Segovia-Viadero, M.; Serrão, E. A.; Canteras-Jordana, J. C.; Gonzalez-Wangueemert, Mercedes
    In salmonids, the release of hatchery-reared fish has been shown to cause irreversible genetic impacts on wild populations. However, although responsible practices for producing and releasing genetically diverse, hatchery-reared juveniles have been published widely, they are rarely implemented. Here, we investigated genetic differences between wild and early-generation hatchery-reared populations of the purple sea urchin Paracentrotus lividus (a commercially important species in Europe) to assess whether hatcheries were able to maintain natural levels of genetic diversity. To test the hypothesis that hatchery rearing would cause bottleneck effects (that is, a substantial reduction in genetic diversity and differentiation from wild populations), we compared the levels and patterns of...

  8. Spatial distribution patterns and movements of Holothuria arguinensis in the Ria Formosa (Portugal)

    Siegenthaler, Andjin; Canovas, Fernando; Gonzalez-Wangueemert, Mercedes
    Holothurian populations are under pressure worldwide because of increasing demand for beche-de-mer, mainly for Asian consumption. Importations to this area from new temperate fishing grounds provide economic opportunities but also raise concerns regarding future over-exploitation. Studies on the habitat preferences and movements of sea cucumbers are important for the management of sea cucumber stocks and sizing of no-take zones, but information on the ecology and behavior of temperate sea cucumbers is scarce. This study describes the small-scale distribution and movement patterns of Holothuria arguinensis in the intertidal zone of the Ria Formosa national park (Portugal).Mark/recapture studieswere performed to record theirmovements over time on different habitats (sand and...

  9. Characterization of 10 new tetranucleotide microsatellite markers for the European eagle owl, Bubo bubo: Useful tools for conservation strategies

    Leon-Ortega, Mario; Gonzalez-Wangueemert, Mercedes
    Bubo bubo is the largest owl in the world, showing a wide geographical distribution throughout the Palaearctic region. It underwent a demographic decline in many European countries during the last century and was considered “vulnerable” (Annex II of the CITES). Nowadays, it is classified as “Least Concern” according to IUCN. Despite its ecological importance and conservation status, few polymorphic molecular markers are available to study its diversity and population genetics. We report on the isolation and development of 10 new microsatellites for the Eagle owl, B. bubo. All loci (10 tetra-nucleotide) are characterized by high polymorphism levels. Number of alleles ranged from 5 to 13 and expected heterozygosity...

  10. Genetic evidence for polygynandry in the black-striped pipefish syngnathus abaster: a microsatellite-based parentage analysis

    Huebner, Kerstin; Gonzalez-Wanguemert, Mercedes; Diekmann, Onno E.; Serrão, Ester
    Sexual selection theory predicts that, in organisms with reversed sex roles, more polyandrous species exhibit higher levels of sexual dimorphism. In the family Syngnathidae (pipefish, seahorses, and seadragons), males provide all parental care by carrying developing embryos on their ventral surfaces, and females develop secondary sex characters. Syngnathids exhibit a variety of genetic mating patterns, making them an ideal group to test predictions of sexual selection theory. Here, we describe the mating system of the black-striped pipefish Syngnathus abaster, using 4 highly variable microsatellites to analyze parentage of 102 embryos. Results revealed that 1) both sexes mate multiple times over the course of a pregnancy...

  11. In two waters: contemporary evolution of lagoonal and marine white seabream (Diplodus sargus) populations

    Gonzalez-Wangueemert, Mercedes; Perez-Ruzafa, Angel
    Brackish water ecosystems are often exposed to wide variations in environmental variables, including temperature and salinity, which may cause strong selective pressures on organisms modifying the genetic patterns of species. The aim of this work was to test whether there is a ‘divergence-with-gene flow’ in coastal lagoon populations of white seabream (Diplodus sargus) (Ria Formosa, S Portugal and Mar Menor, SE Spain) respect to four marine populations, by using partial sequences of cyt b mitochondrial gene and information from nine microsatellite loci. Genetic diversity was highest in both coastal lagoons (Mar Menor and Ria Formosa) considering mitochondrial and nuclear markers. Although some of FST population pairwise comparisons were not...

  12. Assessment of sea cucumber populations from the Aegean Sea (Turkey): first insights to sustainable management of new fisheries

    Gonzalez-Wangueemert, Mercedes; Aydin, Mehmet; Conand, Chantal
    Sea cucumber stocks have been overfished in many countries. As a consequence, several species (Holothuria polii, Holothuria tubulosa and Holothuria mammata) are now caught in Turkish waters without adequate knowledge on their biology and ecology. Here, we address their morphometry, relationships among gutted length and weight, population dynamics, temporal evolution of catches, and we provide the first insights about technical aspects of their fisheries. The largest size classes of H. polii are missing from our sampling collection, possibly due to the heavy fishery pressure on this species. Significant differences in the eviscerated length and weight were found among the Turkish sampled localities for H. polii and H....

  13. West versus East Mediterranean Sea: origin and genetic differentiation of the sea cucumber Holothuria polii

    Valente, Sara; Serrão, Ester; Gonzalez-Wangueemert, Mercedes
    We studied the genetic structure of the sea cucumber Holothuria (Roweothuria) polii (Delle Chiaje 1823) by analysing the mitochondrial DNA variation in two fragments of cytochrome oxidase I (COI) and 16S genes. Individuals were collected in seven locations along the Mediterranean Sea, which cover a wide range of the species distribution. We found high haplotype diversity for COI and moderate diversity for 16S, and low nucleotide diversity for both genes. Our results for the COI gene showed many recent and exclusive haplotypes with few mutational changes, suggesting recent or ongoing population expansion. The Western and Eastern Mediterranean populations exhibited slight but significant genetic differentiation (COI gene) with higher genetic...

  14. New insights into the genetic diversity of zooxanthellae in Mediterranean anthozoans

    Casado-Amezua, Pilar; Machordom, Annie; Bernardo, Joao; Gonzalez-Wanguemert, Mercedes
    Symbiotic dinoflagellates of the genus Symbiodinium, also called zooxanthellae, are found in association with a wide diversity of shallow-water anthozoans. The Symbiodinium genus includes numerous lineages, also referred to as clades or phylotypes, as well as a wide diversity of genetic sub-clades and sub-phylotypes. There are few studies characterizing the genetic diversity of zooxanthellae in Mediterranean anthozoans. In this study, we included anthozoans from the Western Mediterranean Sea and by means of internal transcriber (ITS) and large sub-unit (LSU) rRNA markers we corroborate what has been previously identified, demonstrating that phylotype “Temperate A” is very common among host Cnidaria in this basin. Our finding of fixed differences in ITS and LSU markers that...

  15. Elysia timida (Risso, 1818) three decades of research

    Gimenez-Casalduero, F.; Muniain, C.; Gonzalez-Wangueemert, M.; Garrote-Moreno, A.
    Elysia timida (Risso, 1818) three decades of research.— During the last 30 years, studies on Elysia timida (Risso, 1818) have addressed various aspects related to food sources, photosynthetic efficiency of kleptoplasts, population genetics, chemical ecology and reproductive biology, both in the Mediterranean Sea and in the Mar Menor coastal lagoon. E. timida shows a strong specific interaction with Acetabularia acetabulum, retaining functional chloroplasts for at least 45 days and obtaining extra energy in periods when food resources are scarce. It shows control of parapodia, avoiding pigment photodestruction under oversaturated light conditions. The chemical ecological relationships established between E. timida and its potential predator fish, Thalassoma pavo,...

  16. Do the crabs Goniopsis cruentata and Ucides cordatus compete for mangrove propagules? A field-based experimental approach

    Wellens, Siel; Sandrini-Neto, Leonardo; Gonzalez-Wangueemert, Mercedes; Lana, Paulo
    Mangroves are under threat worldwide by deforestation, overexploitation and climate change. The availability and consumption rates of propagules influence mangrove recruitment and can play a major role in their viability and restoration potential. We assess the potential trophic competition between Goniopsis cruentata and Ucides cordatus, two dominant crab species in the New World, by experimentally comparing herbivory levels between forest stands with varying crab abundance. We hypothesize that herbivory rates (HR) of G. cruentata will be lower in mangroves where it coexists with U. cordatus than in mangroves where U. cordatus is absent. The removal of Rhizophora mangle propagules was very rapid, and HR were overall high and increased through time. However, HR did not...

  17. Multilocus genetic analyses provide insight into speciation and hybridization in aquatic grasses, genus Ruppia

    Martínez-Garrido, Jose; Serrão, Ester; Engelen, Aschwin H.; Cox, Cymon J.; García-Murillo, Pablo; Gonzalez-Wangueemert, Mercedes
    Aquatic plants of the genus Ruppia inhabit some of the most threatened habitats in the world, such as coastal lagoons and inland saline to brackish waters where their meadows play several key roles. The evolutionary history of this genus has been affected by the processes of hybridization, polyploidization, and vicariance, which have resulted in uncertainty regarding the number of species. In the present study, we apply microsatellite markers for the identification, genetic characterization, and detection of hybridization events among populations of putative Ruppia species found in the southern Iberian Peninsula, with the exception of a clearly distinct species, the diploid Ruppia maritima. Microsatellite markers group the...

  18. Genetic differentiation among Parastichopus regalis populations in the Western Mediterranean Sea: potential effects from its fishery and current connectivity

    Maggi, C.; Gonzalez-Wangueemert, M.
    Parastichopus regalis (Cuvier, 1817) is the most expensive seafood product on the Catalonian market (NE Spain), with prices at approximately 130 €/Kg (fresh weight). Despite its ecological and economic importance, biological and genetic information on this sea cucumber species is scarce. Here, we provide both the first insight on the genetic structure of P. regalis using sequences of cytochrome oxidase I (COI) and 16S genes and a morphological description of its population. Individual sea cucumbers were collected in six locations along the Spanish Mediterranean coast, including an area under fishery pressure (Catalonia). We found high haplotype diversity and low nucleotide...

  19. Phylogeographical history of the white seabream Diplodus sargus (Sparidae): Implications for insularity

    Gonzalez-Wangueemert, Mercedes; Froufe, Elsa; Perez-Ruzafa, Angel; Alexandrino, Paulo
    Partial sequences of the mitochondrial control region and its comparison with previously published cytochrome b (cyt-b) and microsatellite data were used to investigate the influence of island isolation and connectivity on white seabream genetic structure. To achieve this, a total of 188 individuals from four island localities (Castellamare and Mallorca, Mediterranean Sea; Azores and Canary Islands, Atlantic Ocean) and five coastal localities (Banyuls, Murcia and Tunisia, Mediterranean Sea; Galicia and Faro, Atlantic Ocean) were analysed. Results showed high haplotype diversity and low to moderate nucleotide diversity in all populations (except for the Canary Islands). This pattern of genetic diversity is attributed to a recent population expansion...

  20. Spatial patterns of genetic diversity in Mediterranean eagle owl Bubo bubo populations

    León-Ortega, Mario; Gonzalez-Wangueemert, Mercedes; Martínez, José E.; Calvo, José F.
    Little information is available on the patterns of genetic connectivity in owls. We studied the genetic structure of the eagle owl Bubo bubo (Linnaeus, 1758) in southeastern Spain at two different spatial scales. Seven microsatellites previously described for this species were used, although only six loci amplified correctly. The observed low genetic variation could be explained by the short dispersal distance, high mortality rate and high degree of monogamy shown by this large nocturnal predator. As expected, the highest genetic isolation was detected in the geographically most isolated population. Significant genetic differentiation was found among study units separated by less than 50 km. The territorial analysis showed...

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