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Ulva-like green algae are notoriously difficult to distinguish because of their great morphological variability and/or similarity, and DNA barcoding approaches are currently indispensable for their identification. However, such approaches often fail if rare or inapparent species are to be detected in large mixed green algal stands. We therefore developed a detection method based on next generation DNA sequencing, suitable for analysis of DNA traces in conserved water samples. A primer pair was developed that allows for amplification of a 475 bp long section within the tufA marker gene. The primers are relatively group specific, as 79.6 % of all reads obtained after quality filtering represented Ulvophyceae. The relatively short target amplicon still allows for good differentiation of Ulvales and Ulothrichales at the species level. Using a database containing tufA sequences of 879 species – thereof 281 Ulvophyceae – we detected predominantly species that were previously observed in our study area in Northern Germany. However, the number of species detected in single sites was generally higher than in earlier barcoding studies, which may be due to drifting genetic traces: Samples collected offshore appeared influenced by Ulvophyceae present within a radius of up to about 1 km in winter and less than 100 m in summer. Nonetheless, this new approach can be used to detect rare species: In one site an undescribed Blidingia species not yet known from our study area was repeatedly detected. Based on these findings the species was discovered and its identity was confirmed by traditional tufA barcoding.

Invasions of freshwater habitats by marine and brackish species have become more frequent in recent years with many of those species originating from the Ponto-Caspian region. Populations of Ponto-Caspian species have successfully established in the North and Baltic Seas and their adjoining rivers, as well as in the Great Lakes-St. Lawrence River region. To determine if Ponto-Caspian taxa more readily acclimatize to and colonize diverse salinity habitats than taxa from other regions, we conducted laboratory experiments on 22 populations of eight gammarid species native to the Ponto-Caspian, Northern European and Great Lakes-St. Lawrence River regions. In addition, we conducted a literature search to survey salinity ranges of these species worldwide. Finally, to explore evolutionary relationships among examined species and their populations, we sequenced the mitochondrial cytochrome c oxidase subunit I gene (COI) from individuals used for our experiments. Our study revealed that all tested populations tolerate wide ranges of salinity, however, different patterns arose among species from different regions. Ponto-Caspian taxa showed lower mortality in fresh water, while Northern European taxa showed lower mortality in fully marine conditions. Genetic analyses showed evolutionary divergence among species from different regions. Due to the geological history of the two regions, as well as high tolerance of Ponto-Caspian species to fresh water, whereas Northern European species are more tolerant of fully marine conditions, we suggest that species originating from the Ponto-Caspian and Northern European regions may be adapted to freshwater and marine environments, respectively. Consequently, the perception that Ponto-Caspian species are more successful colonizers might be biased by the fact that areas with highest introduction frequency of NIS (i.e., shipping ports) are environmentally variable habitats which often include freshwater conditions that cannot be tolerated by euryhaline taxa of marine origin.

Background: During the last years, the effectiveness of DNA barcoding for animal species identification has been proven in many studies, analyzing both vertebrate and invertebrate taxa. In terms of marine organisms, however, most barcoding studies typically focus on economically relevant species, for example, fish, as well asonthedocumentationof hotspots of species diversity, for example, tropical coral reefs or regions of the almost unexplored deep sea regions. In contrast to this, species diversity of “well-known” habitats is nearly neglected. As part of our running project we started to build up a comprehensive DNA barcode library for the metazoan taxa of the North Sea, one of the most extensively studied ecosystems of the world. The North Sea is characterized by a highamountof anthropogenic pressure such as intensive fishing and ship traffic as well as offshore installations. Environmental parameters (e.g., depth, sediment characteristics, temperature, and salinity) of this semi-enclosed shelf sea follow a distinct pattern: high seasonal fluctuations can be observed in southern areas, but low fluctuations are given in the northern regions. This heterogeneity is also displayed in macrobenthic community structures, with a lower number of species in the shallow southern parts (i.e., the German Bight) and more species in the central and northern North Sea. In addition to this, species with a typical Mediterranean-Lusitanean distribution are also known to occur in parts of the North Sea where oceanic influences prevail. Results: Our barcode library includes a broad variety of taxa, including typical taxa of marine barcoding studies, for example, fish or decapod crustaceans. Our on-growing library also includes groups that are often ignored as cnidarians, parasitic crustaceans, echinoderms, mollusks, pantopods, polychaets, and others. In total, our library includes more than 4200 DNA barcodes of more than 600 species at the moment. By using the Barcode of Life Data Systems (BOLD), unique BINs were identified for more than 90% of the analyzed species. Significance: Our data represent a first step towards the establishment of a comprehensive DNA barcode library of the Metazoa of the North Sea. Despite the fact that various taxa are still missing or are currently underrepresented, our results clearly underline the usefulness of DNA barcodes to discriminate the vast majority of the analyzed species. It should be also kept in mind that the benefits of DNA barcoding are not restricted to taxonomic or systematic research only. The rise of modern high-throughput sequencing technologies will change biomonitoring applications and surveys significantly in the coming years. Following this, reference datasets such as ours will become essential for a correct identification of specimens sequenced as part of a metabarcoding study. This is especially true for the North Sea, a marine region that has been massively affected by cargo ship traffic, the exploitation of oil and gas resources, offshore wind parks, and in particular extensive long-term fisheries.

The northeastern Atlantic and Mediterranean small mussel drills of the Ocinebrina aciculata complex are here revised and consist of at least 3 species. The type species, Ocinebrina aciculata (Lamarck, 1822), characterized by a slender shell with rounded whorls and primary and secondary spiral cords of approximately similar size, lives throughout the northeastern Atlantic and Mediterranean Sea at depths usually ranging between 0 and 105 m. Its synonymy is here stabilized by a neotype selection for Murex corallinus Scacchi, 1836. Ocinebrina corallinoides Pallary, 1912 (=Ocinebrina buzzurroi Cecalupo and Mariani, 2008, new synonymy), characterized by a strongly elongate and weakly convex shell and primary and secondary spiral cords of approximately similar size, is endemic to the Gulf of Gabès and is here considered a distinct species, pending genetic studies. Ocinebrina reinai n. sp. is here described from the central Mediterranean Sea (where it is sympatric with O. aciculata) on the basis of morphological diagnostic features of shell (rarest presence of labral tooth, commoner presence of infrasutural apertural denticle, dark spots on the ribs and spiral sculpture with differently sized primary and secondary cords and smaller threads) and radula, confirmed by genetic data. Divergence in COI sequences with sympatric samples of O. aciculata ( > 7%), confirm their status as a distinct species. A comparative table reporting diagnostic features of the congeneric species of the complex and those with which the new species was previously misidentified is offered., Se revisa la taxonomía de las pequeñas especies de gasterópodos murícidos del grupo de Ocinebrina aciculata (Lamarck, 1822). Se consideran válidas tres especies, de las que una se describe como nueva. O. aciculata es la especie tipo del género, está caracterizada por una concha alargada, espiras redondeadas, cordones primarios y secundarios aproximadamente del mismo tamaño, y está distribuida en el área del Atlántico noreste y del Mediterráneo, entre 0 y 105 m de profundidad. Para estabilizar su sinonimia se ha seleccionado un neotipo para Murex corallinus Scacchi, 1836. O. corallinoides Pallary, 1912 (=Ocinebrina buzzurroi Cecalupo and Mariani, 2008, nueva sinonimia) es endémica del Golfo de Gabès, y se distingue por su concha muy alargada y poco convexa, con cordones primarios y secundarios aproximadamente del mismo tamaño. Se considera una especie distinta, a la espera de estudios genéticos. O. reinai n. sp. se describe aqui, y se ha encontrado en Mediterráneo central, donde vive simpátrica con O. aciculata, de la que se distingue por caracteres morfológicos de la concha (rara presencia del diente labral, diente apertural infrasutural más frecuente, manchas oscuras en las costas axiales, cordones primarios y secundarios de tamaño diferente) y de la rádula, confirmados por datos genéticos. Las secuencias del gen mitocondrial COI indican una distancia genética con O. aciculata en simpatría de más de 7%, confirmando su estatus de especie distinta. Se presenta una tabla comparativa de las diferencias entre las especies más similares.

Gastropods are among the most studied group in Antarctica, and taxa with an advanced status of systematic knowledge can be used as a model to study how oceanographic and climatic patterns shaped Recent faunal assemblages. Within the ongoing study of the muricid phylogeny, we have analysed molecular and morphological data from species traditionally ascribed to the muricid subfamily Trophoninae. Particularly, the availability of specimens collected in the Southern Ocean and surrounding basins allowed to demonstrate as the genera Pagodula, Xymenopsis, Xymene and Trophonella, which are traditionally classified in the Trophoninae, actually belong to a distinct lineage, for which the new subfamily Pagodulinae is herein introduced. We propose and discuss a possible framework for the origin and radiation of Antarctic muricids.

I muricidi sono un gruppo di gasteropodi predatori composto da più di 1600 specie conosciute, sono tra i principali componenti delle comunità bentoniche e rivestono importanti interessi commerciali in alcune regioni del mondo. La loro origine risale al periodo di grande diversificazione noto come “Rivoluzione Marina del Mesozoico”, nel quale i predatori di questa famiglia cominciarono a diffondersi grazie alla spinta evolutiva fornita dall'efficienza della loro strategia trofica. Le linee filetiche appartenenti a questa radiazione sono suddivise in dieci sottofamiglie, identificate tradizionalmente dalla morfologia cochigliare e, soprattutto, da quella radulare. La radula, infatti, potrebbe aver rivestito il ruolo di novità evolutiva nell'emergenza delle varie linee filetiche, grazie al suo diretto coinvolgimento nella predazione. La grande diversificazione morfologica ed ecologica permette di utilizzare questi gasteropodi come modello di studio per l'evoluzione degli adattamenti trofici, ma le conoscenze a disposizione, soprattutto a livello filogenetico, sono ancora insufficienti per consentire la formulazione d'ipotesi robuste. Lo scopo di questo studio è gettare le basi per la definizione di un'ipotesi evolutiva per i muricidi. Per questo motivo è stata costruita una filogenesi molecolare, ed è stata utilizzata come riferimento per analizzare le morfologie radulari, le diverse ecologie trofiche e gli eventi che potrebbero averne promosso la diversificazione. Utilizzando un dataset rappresentativo, è stata costruita la prima filogenesi molecolare contenente tutte le sottofamiglie di muricidi, con la quale è stata definita una base per il rinnovamento della classificazione. La filogenesi ha confermato la monofilia delle sottofamiglie Coralliophilinae, Ergalataxinae, Rapaninae, Typhinae e Haustrinae, in accordo con la classificazione tradizionale. La polifilia delle Trophoninae è stata suggerita in studi precedenti, e i dati molecolari hanno evidenziato l'esistenza di due linee filetiche indipendenti in questa sottofamiglia. Le Ocenebrinae sono monofiletiche solamente con l'esclusione del genere Vitularia. A differenza della classificazione tradizionale, le Muricinae e Muricopsinae, le sottofamiglie più rappresentative, non sono monofiletiche. Un'analisi preliminare, condotta calibrando un orologio molecolare, ha fornito delle datazioni parzialmente discordanti rispetto all‟apparizione delle sottofamiglie nel record fossile. In alcune linee filetiche (principalmente nelle Coralliophilinae) l'elevato tasso di mutazione può aver determinato una incorretta stima dell‟origine del clade.Nell'analisi morfologica sono state esaminate, descritte confrontate con la filogenesi molecolare le radule di specie appartenenti a nove delle dieci sottofamiglie. Questo esame ha messo in evidenza molti caratteri trascurati nelle classificazioni tradizionali. Dalla descrizione sono stati ricavati 20 caratteri morfologici utilizzati in due analisi cladistiche, le quali hanno messo in evidenza la presenza di un segnale filogenetico. Nonostante sia stata frequentemente messa in discussione, la morfologia radulare mostra un buon livello di utilità filogenetica se associata ad altri caratteri (ad esempio anatomici). Utilizzando un metodo comparativo, la filogenesi molecolare è stata confrontata con le strategie trofiche conosciute in alcune sottofamiglie, in modo da formulare un'ipotesi sulla loro evoluzione. I muricidi sono caratterizzati da una grande diversificazione delle tecniche predatorie, dalla capicità di modificare strategia secondo le condizioni ecologiche e dalla variabilità nella scelta delle prede. Questa diversità, probabilmente assente nell'ipotetico antenato comune, comparve indipendente nelle linee filetiche della famiglia.