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Blooms of centric diatoms are a common feature in the Bilbao estuary during summer when river flow is at its lowest and water temperature is above 20ºC. To gain insight into the specific composition of these diatom blooms, net samples and cultures of estuarine isolates were analysed under the scanning electron microscope (SEM) and by molecular analyses of the Internal Transcribed Spacers 1 and 2 plus the coding region 5.8S (ITS region) and the 28S rRNA gene. Seven species of solitary centric diatoms belonging to four genera were found in the estuary including: Conticribra weissflogii, Cyclotella atomus var. atomus, Cyclotella cryptica, Cyclotella marina, Cyclotella meneghiniana, Discostella pseudostelligera and Thalassiosira pseudonana. Dominant species during blooms were C. meneghiniana and Co. weissflogii in the upper estuary and D. pseudostelligera and T. pseudonana in the middle estuary. The morphological traits used to differentiate between species pairs of similar morphology (C. meneghiniana/C. cryptica or D. pseudostelligera/D. woltereckii) were observed to vary with environmental conditions, denoting a great deal of phenotypic plasticity which would hinder accurate identification of the species when using morphological approaches alone.

Genetic studies have shown a significant hybridization of local populations of Apis mellifera in the Canary Islands, as a consequence of queen importation. Since La Palma Island was a probable exception to this hybridization rule, a local honey bee Conservation Project was developed. As a first step, the genetic characterization of the population was performed with the scope of generating fundamental knowledge to correctly manage honey bee genetic resources. In this sense, the origin of the Canarian honey bee is at issue, since diverse morphological and genetic studies have shown it to be either African or European. In our study, 499 colonies from La Palma were analyzed using mitochondrial DNA, microsatellites and wing geometric morphometric data. Hybridization from the C evolutionary lineage was observed mainly at mitochondrial level, but this hybridization was focused on a restricted area and hybrid colonies were detected for replacement. All genetic and geometric morphometric results showed the Canaria...

17 páginas, 8 figuras, 4 tablas, A single cell of the dinoflagellate genus Fukuyoa was isolated from the island of Formentera (Balearic Islands, west Mediterranean Sea), cultured, and characterized by morphological and molecular methods and toxin analyses. This is the first report of the Gambierdiscus lineage (genera Fukuyoa and Gambierdiscus) from the western Mediterranean Sea, which is cooler than its eastern basin. Molecular analyses revealed that the Mediterranean strain belongs to F. paulensis and that it bears LSU rDNA sequences identical to New Zealand, Australian, and Brazilian strains. It also shared an identical sequence of the more variable ITS-rDNA with the Brazilian strain. Toxin analyses showed the presence of maitotoxin, 54-deoxyCTX1B, and gambieric acid A. This is the first observation of the two latter compounds in a Fukuyoa strain. Therefore, both Gambierdiscus and Fukuyoa should be considered when as contributing to ciguatera fish poisoning. Different strains of Fukuyoa form a complex of morphologically cryptic lineages where F. paulensis stands as the most distantly related nominal species. The comparison of the ITS2 secondary structures revealed the absence of CBCs among strains. The study of the morphological and molecular traits depicted an unresolved taxonomic scenario impacted by the low strains sampling, Financial support for this research was provided by the Basque Government (project IT699-13). A grant from the University of the Basque Country (UPV/EHU) to H. David also supported this study

International audience; Traditional morphometrics, allozymes, and mitochondrial data have supported a close relationship between the M branch subspecies A. m. iberiensis and the North African subspecies (A branch). However, studies using nuclear DNA markers have revealed a clear distinction between the latter and the two European M branch subspecies. In help resolve this paradox, we analyzed 663 colonies from six European and African subspecies. A geometric morphometrics approach was applied to the analysis of wing shape, and the results were compared with data of six microsatellite loci. Both data sets were found to be highly consistent and corroborated a marked divergence of West European subspecies from North African ones. This supports the hypothesis that the presence of the African lineage mitotype in Iberian honey bee populations is likely the consequence of secondary introductions, with a minimal African influence within the current Iberian genetic background. Wing geometric morphometrics appears more appropriate than mitochondrial DNA analysis or traditional morphometrics in the screening and identification of the Africanization process.