We investigated epizoic algal assemblages on the shell of European pond turtles (Emys orbicularis) during two years (2013–2014). A total of 60 Emys orbicularis were captured in the three shallow Mediterranean wetlands located in Camargue. Epizoic algae on the plastron (below the shell) and carapace (above the shell) were sampled, identified and counted. Seventy-seven epizoic algal species were identified on the carapace and plastron and comprised in 51 Bacillariophyta, 11 Chlorophyta, 7 Cyanophyta, 6 Euglenophyta, 1 Dinophyta and1Xanthophyta taxa. Our findings indicated a distinct distribution of epizoic algae according to taxonomical group density; Chlorophyta, and Cyanophyta were dominant on the carapace whereas the Xanthophyta (genus Vaucheria sp.) was dominant on the plastron. Turtleassociated algal assemblages did not differ among the wetlands

The brown alga Cystoseira amentacea (Phaeophyceae, kingdom Stramenopiles) constitutes an extensive belt in the shallowest horizon of the infralittoral (the infralittoral fringe), in the Mediterranean Sea. Hydrodynamic modelling was used to infer connectivity between populations of C. amentacea of the Bay of Marseille (Provence, France, NW Mediterranean) and to test the correlation between genetic and hydrodynamic connectivity. We genotyped 183 individuals from six populations at six microsatellite loci. Current fields were computed at a fine resolution by a 3D numerical model simultaneously utilizing the local winds, the Rhone River inputs and offshore circulation. The Lagrangian trajectories of the propagules (zygotes, or rafts) were computed with the ICHTHYOP software, for both NW and SE strong wind forcing (11–12 m·s^-1). Cystoseira amentacea displayed a strong and significant genetic structure, not correlated with the geographic distance, i.e. a lack of isolation by distance (IBD). The pairs of sites with the lowest F_ST were those connected by the current patterns. The time needed for a zygote or a raft to travel from one location to another ranged from 4 to 18 h (i.e. within the survival time of a zygote) and for distances of up to 23 km. Despite the very low dispersal capability of the zygotes, long-distance dispersal is therefore possible. Several non-exclusive processes can account for the genetic structure of C. amentacea populations, such as step-by-step local dispersal, long-distance dispersal of zygotes and rafts by currents, during storms, and the “priority effect”, i.e. the importance of the timing of arrival of the propagules.

The delimitation of species in the Gracilariales is often difficult due to the lack of diagnostic morphological characters. As a result, non-native species are often misidentified without the use of molecular tools. Recently, studies have investigated the agar quality of the dominant gracilarioid species in the Laguna San Ignacio in Baja Califronia Sur, Mexico, including Vergara-Rodarte et al., (2016) published in the May edition of Cryptogamie, Algologie. The species has been reported as Gracilaria pacifica, G. vermiculophylla and Gracilariopsis sp. Using a combination of three mitochondrial and plastid markers, we identified this species as G. parvispora, extending the known distribution of this non-native species in Baja California. Due to the potential of G. parvispora as a source of agar, more detailed studies of on the invasion history and surveys are necessary in the eastern Pacific to determine its current distribution and impacts on the native biodiversity.

As Sphaerococcus coronopifolius Stackhouse (Gigartinales, Rhodophyta) is a seaweed that has considerable potential for commercial uses, and as its life history in the various seas where it lives has not yet been thoroughly explored, we carried out a pilot study on the reproduction in nature and in vitro culture of field specimens established on the coasts of the Lazio region (Tyrrhenian Sea, central Italy). Spermatangia were not observed on the gametophyte (S. coronopifolius) and the tetrasporophyte of the species (Haematocelis fissurata) was not found either in the study site or in culture. As the carpospores developed directly into the gametophyte, we may conclude that this species reproduces itself, in both the study site and in culture, through a direct-type life history. It may thus be possible to use the variety of the clonal individuals growing on the coasts of Lazio for a future cultivation of S. coronopifolius on a large scale.

Cette étude fournit de nouvelles connaissances sur les préférences écologiques Pediastrum, plus c´est la premiere description detaillee des populations naturelles et des cultures au Mexique. Elle fournit des informations sur l'ultrastructure et les conditions environnementales de Pediastrum sensu lato dans en endroits dans le centre du pays. Ce genre (Hydrodictyaceae, Chlorophyceae) n'a pas une origine monophyletique plutot a ete divisé en cinq genres : Lacunastrum, Monactinus, Parapediastrum, Pseudopediastrum et Stauridium. Les spécimens étudiés ont été recueillies entre Octobre 2009 et Novembre 2013. Les microscopes optique et electronique ont revele la presence de sept especes. Parmi cellesci, Monactinus simplex, Pediastrum duplex, Pseudopediastrum boryanum et Stauridium tetras ont une distribution dans le monde entier. Au lieu de cela, Monactinus simplex var. echinulatum, M. simplex var. sturmii et Pediastrum simplex var. clathratum ont été enregistrées comme des taxa rares. La distribution des especes en examinant la litterature de 1841–2015 a signalé l'existence de 23 taxa dans 17 états du Mexique, où les états de Mexique, Veracruz et Michoacan avec plusieurs especes. L'analyse Canonicale des Correspondances a montre que les relations entre les especes et les conditions environnementales des taxons rares sont liées à des températures élevées, des sites bien oxygénés et des conditions eutrophes.

This study gives new insights into ecological preferences of the Pediastrum genus as well as the first detailed description of its natural populations and cultures in Mexico. This artile provides information on the ultrastructure and environmental conditions of Pediastrum sensu lato at six locations in the center of Mexico. This genus (Hydrodictyaceae, Chlorophyceae) does not have a monophyletic origin; rather, it has been divided into the following five genera: Lacunastrum, Monactinus, Parapediastrum, Pseudopediastrum and Stauridium. The study specimens were collected between October 2009 and November 2013. Light and scanning electron microscopy revealed the presence of seven species. Of these, Monactinus simplex, Pediastrum duplex, Pseudopediastrum boryanum and Stauridium tetras have worldwide distribution. By contrast, Monactinus simplex var. echinulatum, M. simplex var. sturmii and Pediastrum simplex var. clathratum were found to be rare taxa. The species distribution as determined by literature review of articles from 1841 to 2015 registered the presence of 23 taxa in 17 Mexican states, namely, Mexico City, Veracruz and Michoacan which were the sites with the largest numbers of species. Canonical correspondence analyses showed that the relationships between the species and the environmental conditions of the rare taxa are related to well-oxygenated, high temperature and eutrophic conditions.

Chrysodidymus represents a monotypic genus of silica-scaled chrysophytes, with well characterised morphology and ultrastructure, as well as pretty known ecology. However, the taxonomic status of this genus remains ambiguous due to the absence of relevant sequence data. In this study, we have aimed to genetically characterize a newly established C. synuroideus culture to elucidate the taxonomy of Chrysodidymus. Our multigene SSU rDNA LSU rDNA rbcL phylogenetic analysis inferred C. synuroideus to be significantly nested deeply inside the genus Synura. This convincing evidence led us to propose a new combination for this taxon — Synura synuroidea (Prowse) Pusztai et al., comb. nov.