Genomic differentiation of three pico-phytoplankton species in the Mediterranean Sea.

For more than a decade, high-throughput sequencing has transformed the study of marine planktonic communities and has highlighted the extent of protist diversity in these ecosystems. Nevertheless, little is known relative to their genomic diversity at the species-scale as well as their major speciation mechanisms. An increasing number of data obtained from global scale sampling campaigns is becoming publicly available, and we postulate that metagenomic data could contribute to deciphering the processes shaping protist genomic differentiation in the marine realm.

Highly restricted dispersal in habitat-forming seaweed may impede natural recovery of disturbed populations.

Cystoseira sensu lato (Class Phaeophyceae, Order Fucales, Family Sargassaceae) forests play a central role in marine Mediterranean ecosystems. Over the last decades, Cystoseira s.l.

New microsatellite DNA markers to resolve population structure of the convict surgeonfish, Acanthurus triostegus, and cross-species amplifications on thirteen other Acanthuridae.

Microsatellites are widely used to investigate connectivity and parentage in marine organisms. Despite surgeonfish (Acanthuridae) being dominant members of most reef fish assemblages and having an ecological key role in coral reef ecosystems, there is limited information describing the scale at which populations are connected and very few microsatellite markers have been screened. Here, we developed fourteen microsatellite markers for the convict surgeonfish Acanthurus triostegus with the aim to infer its genetic connectivity throughout its distribution range.

From population connectivity to the art of striping Russian dolls: the lessons from corals.

Here, we examined the genetic variability in the coral genus , in particular within the Primary Species Hypothesis PSH09, identified by Gélin, Postaire, Fauvelot and Magalon (2017) using species delimitation methods [also named complex , Schmidt-Roach, Miller, Lundgren, & Andreakis (2014)] and which was found to split into three secondary species hypotheses (SSH09a, SSH09b, and SSH09c) according to assignment tests using multi-locus genotypes (13 microsatellites). From a large sampling (2,507 colonies) achieved in three marine provinces [Western Indian Ocean (WIO), Tropical Southwestern Pacific (TSP), and Southeast Polynesia (SEP)], genetic structuring analysis conducted with two clustering analyses (structure and DAPC) using 13 microsatellites revealed that SSH09a was restricted to the WIO while SSH09b and SSH09c were almost exclusively in the TSP and SEP. More surprisingly, each SSH split into two to three genetically differentiated clusters, found in sympatry at the reef scale, leading to a pattern of nested hierarchical levels (PSH > SSH > cluster), each level hiding highly differentiated genetic groups.

Considering reefscape configuration and composition in biophysical models advance seascape genetics.

Previous seascape genetics studies have emphasized the role of ocean currents and geographic distances to explain the genetic structure of marine species, but the role of benthic habitat has been more rarely considered. Here, we compared the population genetic structure observed in West Pacific giant clam populations against model simulations that accounted habitat composition and configuration, geographical distance, and oceanic currents. Dispersal determined by geographical distance provided a modelled genetic structure in better agreement with the observations than dispersal by oceanic currents, possibly due to insufficient spatial resolution of available oceanographic and coastal circulation models.

Superclone Expansion, Long-Distance Clonal Dispersal and Local Genetic Structuring in the Coral Pocillopora damicornis Type β in Reunion Island, South Western Indian Ocean.

The scleractinian coral Pocillopora damicornis type β is known to present a mixed reproduction mode: through sexual reproduction, new genotypes are created, while asexual reproduction insures their propagation. In order to investigate the relative proportion of each reproduction mode in P. damicornis type β populations from Reunion Island, Indian Ocean, clonal propagation along the west coast was assessed through four sampling sites with increasing geographical distance between sites.

Endangered New Caledonian endemic mushroom coral Cantharellus noumeae in turbid, metal-rich, natural and artificial environments.

Since its description in 1984, little attention has been paid to the New Caledonian endemic mushroom coral Cantharellus noumeae (Fungiidae), an IUCN Red-listed, endangered coral species. Our study presents the first ever quantitative assessment conducted on C. noumeae populations for two contrasting sites in the same turbid bay.

Resurrection of Indian Ocean humbug damselfish, Dascyllus abudafur (Forsskål) from synonymy with its Pacific Ocean sibling, Dascyllus aruanus (L.).

Previous phylogeographic studies of the humbug damselfish, a widespread Indo-West Pacific coral reef fish, have revealed a split of two main mitochondrial lineages distributed on either side of the Indo-Pacific barrier. This has been interpreted as the result of vicariance. It has been hypothesized that reproductive barriers might currently limit gene flow between humbug damselfish populations from the Indian Ocean and the Pacific Ocean.

Genetic relatedness in groups of the humbug damselfish Dascyllus aruanus: small, similar-sized individuals may be close kin.

Kin selection plays an important role in the evolution of social behaviour in terrestrial systems. The extent to which kin selection influences the evolution of social behaviour in marine systems is largely unexplored. Generally, it is considered that kin selection is irrelevant in marine systems, because it is assumed that the dispersing larval phase of marine organisms will break up kin associations.

Parallel responses of species and genetic diversity to El Niño Southern Oscillation-induced environmental destruction.

Species diversity within communities and genetic diversity within species are two fundamental levels of biodiversity. Positive relationships between species richness and within-species genetic diversity have recently been documented across natural and semi-natural habitat islands, leading Vellend to suggest a novel macro-ecological pattern termed the species-genetic diversity correlation. We tested whether this prediction holds for areas affected by recent habitat disturbance using butterfly communities in east Kalimantan, Indonesia.

Short-term impact of 1997/1998 ENSO-induced disturbance on abundance and genetic variation in a tropical butterfly.

In order to assess the short-term impact of habitat loss after disturbance, we studied Arhopala epimuta (Lepidoptera: Lycaenidae) populations in 5 landscapes in Borneo that were differentially affected by the 1997/1998 El Niño Southern Oscillation-induced drought and fire. Sampling was conducted before (1997) and after (1998 and 2000) disturbance. This study combined demographic and genetic data inferred from the analysis of 5 microsatellite loci and mitochondrial DNA (mtDNA) control region sequences.