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Papers by Ricardo Pereyra

Journal of evolutionary biology, 2013

Parallel evolution has been invoked as a forceful mechanism of ecotype and species formation in m... more Parallel evolution has been invoked as a forceful mechanism of ecotype and species formation in many animal taxa. However, parallelism may be difficult to separate from recently monophyletically diverged species that are likely to show complex genetic relationships as a result of considerable shared ancestral variation and secondary hybridization in local areas. Thus, species' degrees of reproductive isolation, barriers to dispersal and, in particular, limited capacities for long-distance dispersal will affect demographical structures underlying mechanisms of divergent evolution. Here, we used nine microsatellite DNA markers to study intra- and interspecific genetic diversity of two recently diverged species of brown macroalgae, Fucus radicans (L. Bergström & L. Kautsky) and F. vesiculosus (Linnaeus), in the Baltic Sea. We further performed biophysical modelling to identify likely connectivity patterns influencing the species' genetic structures. For each species, we found intraspecific contrasting patterns of clonality incidence and population structure. In addition, strong genetic differentiation between the two species within each locality supported the existence of two distinct evolutionary lineages (FST = 0.15–0.41). However, overall genetic clustering analyses across both species' populations revealed that all populations from one region (Estonia) were more genetically similar to each other than to their own taxon from the other two regions (Sweden and Finland). Our data support a hypothesis of parallel speciation. Alternatively, Estonia may be the ancestral source of both species, but is presently isolated by oceanographic barriers to dispersal. Thus, a limited gene flow in combination with genetic drift could have shaped the seemingly parallel structure.

Ecosphere, 2012

Citation: Nylund, G. M., R. T. Pereyra, H. L. Wood, K. Johannesson, and H. Pavia. 2012. Increased... more Citation: Nylund, G. M., R. T. Pereyra, H. L. Wood, K. Johannesson, and H. Pavia. 2012. Increased resistance towards generalist herbivory in the new range of a habitat-forming seaweed. Ecosphere 3(12):125. http://dx.

Coral reefs, 2012

Determining the spatial genetic structure within and among cold-water coral populations is crucia... more Determining the spatial genetic structure within and among cold-water coral populations is crucial to understanding population dynamics, assessing the resilience of cold-water coral communities and estimating genetic effects of habitat fragmentation for conservation. The spatial distribution of genetic diversity in natural populations depends on the species' mode of reproduction, and coral species often have a mixed strategy of sexual and asexual reproduction. We describe the clonal architecture of a cold-water coral reef and the fine-scale population genetic structure (\35 km) of five reef localities in the NE Skagerrak. This study represents the first of this type of analysis from deep waters. We used thirteen microsatellite loci to estimate gene flow and genotypic diversity and to describe the fine-scale spatial distribution of clonal individuals of Lophelia pertusa. Within-population genetic diversity was high in four of the five reef localities. These four reefs constitute a genetic cluster with asymmetric gene flow that indicates metapopulation dynamics. One locality, the Säcken reef, was genetically isolated and depauperate. Asexual reproduction was found to be a highly important mode of reproduction for L. pertusa: 35 genetic individuals were found on the largest reef, with the largest clone covering an area of nearly 300 m 2 .

BMC ecology, 2012

Background: Most species of brown macroalgae recruit exclusively sexually. However, Fucus radican... more Background: Most species of brown macroalgae recruit exclusively sexually. However, Fucus radicans, a dominant species in the northern Baltic Sea, recruits new attached thalli both sexually and asexually. The level of asexual recruitment varies among populations from complete sexual recruitment to almost (> 90%) monoclonal populations. If phenotypic traits have substantial inherited variation, low levels of sexual activity will decrease population variation in these traits, which may affect function and resilience of the species. We assessed the level of inherited variation in nine phenotypic traits by comparing variation within and among three monoclonal groups and one group of unique multilocus genotypes (MLGs) sampled in the wild.

9th International Phycological Congress Japan, Jan 1, 2009

Search: onr:"swepub:oai:services.scigloo.org:112231" > Rapid speciation ... more Search: onr:"swepub:oai:services.scigloo.org:112231" > Rapid speciation of... ... Pereyra, Ricardo. T., 1974-(author) Göteborgs universitet Göteborgs universitet, Institutionen för marin ekologi Tjärnö marinbiologiska laboratorium University of Gothenburg Faculty of ...

Population Structure, Genetic Diversity and Dispersal of Cichlid Fishes from Lake Malawi. Ricardo... more Population Structure, Genetic Diversity and Dispersal of Cichlid Fishes from Lake Malawi. Ricardo T Pereyra University of East Anglia, 2003.

Conservation Genetics …

We developed and characterized 20 microsatellite primer loci for the northern shrimp Pandalus bor... more We developed and characterized 20 microsatellite primer loci for the northern shrimp Pandalus borealis. All 20 loci were polymorphic with number of alleles ranging from 3 to 36 and with observed heterozygosity between 0.04 and 0.93. In addition, we tested the utility of these markers in three related shrimp species, P. montagui, Atlantopandalus propinqvus and Dichelopandalus bonnieri. These new markers will prove useful in the identification of stock structure and hence, assessment of the commercially important species P. borealis.

Journal of …, Jan 1, 2011

Asexual reproduction by cloning may affect the genetic structure of populations, their potential ... more Asexual reproduction by cloning may affect the genetic structure of populations, their potential to evolve, and, among foundation species, contributions to ecosystem functions. Macroalgae of the genus Fucus are known to produce attached plants only by sexual recruitment. Recently, however, clones of attached plants recruited by asexual reproduction were observed in a few populations of Fucus radicans Bergström et L. Kautsky and F. vesiculosus L. inside the Baltic Sea. Herein we assess the distribution and prevalence of clonality in Baltic fucoids using nine polymorphic microsatellite loci and samples of F. radicans and F. vesiculosus from 13 Baltic sites. Clonality was more common in F. radicans than in F. vesiculosus, and in both species it tended to be most common in northern Baltic sites, although variation among close populations was sometimes extensive. Individual clonal lineages were mostly restricted to single or nearby locations, but one clonal lineage of F. radicans dominated five of 10 populations and was widely distributed over 550 · 100 km of coast. Populations dominated by a few clonal lineages were common in F. radicans, and these were less genetically variable than in other populations. As thalli recruited by cloning produced gametes, a possible explanation for this reduced genetic variation is that dominance of one or a few clonal lineages biases the gamete pool resulting in a decreased effective population size and thereby loss of genetic variation by genetic drift. Baltic fucoids are important habitat-forming species, and genetic structure and presence of clonality have implications for conservation strategies.