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We investigate mitochondrial (COI, 16S rDNA) and nuclear (ITS2, 28S rDNA) genetic structure of North East Atlantic lineages of Terebellides, a genus of sedentary annelids mainly inhabiting continental shelf and slope sediments. We demonstrate the presence of more than 25 species of which only seven are formally described. Species boundaries are determined with molecular data using a broad range of analytical methods. Many of the new species are common and wide spread, and the majority of the species are found in sympatry with several other species in the complex. Being one of the most regularly encountered annelid taxa in the North East Atlantic, it is more likely to find an undescribed species of Terebellides than a described one.

This study uses genetic algorithms to formulate and develop land use plans. The restrictions to be imposed and the variables to be optimized are selected based on current local and national legal rules and experts' criteria. Other considerations can easily be incorporated in this approach. Two optimization criteria are applied: land suitability and the shape-regularity of the resulting land use patches. We consider the existing plots as the minimum units for land use allocation. As the number of affected plots can be large, the algorithm execution time is potentially high. The work thus focuses on implementing and analyzing different parallel paradigms: multicore parallelism, cluster parallelism and the combination of both. Some tests were performed that show the suitability of genetic algorithms to land use planning problems.

Regeneration, the ability to restore body parts after an injury or an amputation, is a widespread but highly variable and complex phenomenon in animals. While having fascinating scientists for centuries, fundamental questions about the cellular basis of animal regeneration as well as its evolutionary history remain largely unanswered. We study regeneration of the marine annelid Platynereis dumerilii, an emerging comparative developmental biology model, which, like many other annelids, displays important regenerative abilities. If the posterior part of the body is amputated, P. dumerilii worms are able to regenerate the posteriormost differentiated part of the body and stem cell-rich growth zone that allows to make new segments which replace the amputated ones. We show that posterior regeneration is a rapid process that follows a well reproducible paths and timeline, going through specific stages that we thoroughly defined. Wound healing is achieved by one day post-amputation and a regeneration blastema forms one day later. At this time point, some tissue specification already occurs, and a functional posterior growth zone is re-established as early as three days after amputation. Regeneration is only influenced in a minor manner by worm size and position of the amputation site along the anteroposterior axis of the worm and regenerative abilities persist upon repeated amputations without important alterations of the process. We also show that intense cell proliferation occurs during regeneration and that cell divisions are strictly required for regeneration to normally proceed. Finally, through several 5-ethynyl-2'-deoxyuridine (EdU) pulse and chase experiments, we provide evidence in favor of a local origin of the blastema, whose constituting cells mostly derive from the segment immediately abutting the amputation plane. The detailed characterization of P. dumerilii posterior body regeneration presented in this article provides the foundation for future mechanistic and comparative studies of regeneration in this species.

Based on material collected during the BIOICE project, the taxonomy and distribution of Terebellides (Polychaeta; Trichobranchidae) in Icelandic waters is presented. Terebellides stroemii Sars, 1853 and Terebellides gracilis Malm, 1874 (as Terebellides williamsae Jirkov, 1989) were previously reported from the area. Terebellides atlantis Williams, 1984 is reported for the first time after the original description and redescribed. Terebellides bigeniculatus sp. nov. is diagnosed by the presence of two thoracic chaetigers with geniculate chaetae. Terebellides williamsae Jirkov, 1989 is proposed as a junior synonym of T. gracilis, whose holotype is redescribed herein. Several body characters with high taxonomic value in Terebellides are reviewed under the SEM; additions to the diagnosis and new potential characters for a future taxonomic revision and phylogenetic study of the genus are also suggested. The geographical and bathymetric distribution of each species in relation to the GIF Ridge is discussed, and a key to Terebellides species from North East Atlantic waters is provided.