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The three datasets are obtained directly from the papers we discuss or from their authors. The first two datasets concern recruitment of cockles and Balthic tellins at seven sites in the Wadden Sea. The third dataset contains data on dredging and suitability for knots at 272 1 km2 grid cells in the western Wadden Sea.

Highly populated coastal environments receive large quantities of treated and untreated wastewater from human and industrial sources. Bivalve molluscs accumulate and retain contaminants, and their analysis provides evidence of past contamination. Rivers and precipitation are major routes of bacteriological pollution from surface or sub-surface runoff flowing into coastal areas. However, relationships between runoff, precipitation, and bacterial contamination are site-specific and dependent on the physiographical characteristics of each catchment. In this work, we evaluated the influence of precipitation and river discharge on molluscs' Escherichia coli concentrations at three sites in Central Italy, aiming at quantifying how hydrometeorological conditions affect bacteriological contamination of selected bivalve production areas. Rank-order correlation analysis indicated a stronger association between E. coli concentrations and the modelled Pescara River discharge maxima (r = 0.69) than between E. coli concentration and rainfall maxima (r = 0.35). Discharge peaks from the Pescara River caused an increase in E. coli concentration in bivalves in 87% of cases, provided that the runoff peak occurred 1–6 days prior to the sampling date. Precipitation in coastal area was linked to almost 60% of cases of E. coli high concentrations and may enhance bacterial transportation offshore, when associated with a larger-scale weather system, which causes overflow occurrence. HIGHLIGHTS Using a grid-distributed hydrological model to assess hydrometeorological conditions in the absence of direct measurements.; Analysis of a previous uninvestigated area.; New discharge threshold determining Escherichia coli concentration peaks found in Central Italy in order to allow the development of an early warning system for risk assessment.

Contaminants of Emerging Concerns (CECs) are defined as chemicals not commonly monitored in aquatic ecosystems, but with the potential to cause adverse effects on biota. CECs include Endocrine Disrupting Chemicals (EDCs) and Neuro-Endocrine disruptors (NEDs) of vertebrates. However, most invertebrates only rely on neuroendocrine systems to maintain homeostatic processes. Although conserved neuroendocrine components have been characterized in ecologically relevant groups, limited knowledge on invertebrate neuroendocrinology makes it difficult to define EDCs and NEDs in most species. The monoamine serotonin (5-hydroxytryptamine, 5-HT) acts both as a neurotransmitter and as a peripheral hormone in mammals. In molluscs, 5-HT is involved in multiple physiological roles and molecular components of the serotonergic system have been identified. This review is focused on the effects of CECs on the serotonergic system of bivalve molluscs. Bivalves are widespread in all aquatic environments, estuarine and coastal areas in particular, where they are exposed to a variety of chemicals. In bivalves, 5-HT is involved in gametogenesis and spawning, oocyte maturation and sperm motility, regulates heart function, gill ciliary beating, mantle/siphon function, the ‘‘catch’’ state of smooth muscle and immune responses. Components of 5-HT transduction (receptors and signaling pathways) are being identified in several bivalve species. Different CECs have been shown to affect bivalve serotonergic system. This particularly applies to antidepressants, among the most commonly detected human pharmaceuticals in the aquatic environment. In particular, selective serotonin reuptake inhibitors (SSRIs) are frequently detected in seawater and in bivalve tissues. Information available on the effects and mechanisms of action of SSRIs on the serotonergic system of adult bivalves is summarized. Data are also reported on the effects of CECs on development of neuroendocrine pathways of early larval stages, in particular on the effects of model EDCs in the marine mussel Mytilus galloprovincialis. Overall, available data point at the serotonergic system as a sensitive target for neuroendocrine disruption in bivalves. The results contribute drawing Adverse Outcome Pathways (AOPs) for model EDCs and SSRIs in larvae and adults. However, basic research on neuroendocrine signaling is still needed to evaluate the potential impact of neuroendocrine disruptors in key invertebrate groups of aquatic ecosystems.

Bivalve molluscs are important fishing resources for human consumption around the world. However, for safe consumption, good hygiene conditions must be ensured throughout the production chain. Eating bivalve molluscs, particularly raw, can pose a significant health risk to consumers because they can act as vectors of infectious pathogens. This study aimed to evaluate the microbiological quality of mussels from Niterói, RJ and the use of cooking to ensure food safety, as well as assessing the susceptibility of Escherichia coli and coagulase-positive Staphylococcus strains to different antimicrobials. Therefore, microbiological analyzes were performed on mussels Perna perna before and after thermal processing, the impact of cooking on the microorganisms was verified. Cooking the mussels in water at 95°C for 1 (one) minute reduced product contamination. The use of the time x temperature binomial was sufficient to reduce pathogenic microorganisms to acceptable levels according to Brazilian legislation, although the pathogens were only completely eliminated after five minutes. The bacteria investigated had a high antibiotic resistance index: 66% of E. coli strains and 34.78% of coagulase-positive Staphylococcus strains were found to be resistant to multiple drugs.

This study aimed to assess the presence of thermotolerant Campylobacter spp., as one of the most important foodborne zoonotic pathogens, in three shellfish species: mussels (Mytilus galloprovincialis), oysters (Ostrea edulis) and queen scallops (Aequipecten opercularis). The samples were collected from nine locations in the Istrian aquatory, Croatia. Isolation of Campylobacter was done according to standard ISO method, and species were identified using multiplex PCR. Isolates identified as C. jejuni and C. lari were genotyped using multilocus sequence typing (MLST) to determine the potential source of contamination. Among 108 examined samples of bivalve molluscs, mussels dominated and were the only ones found positive for the presence of Campylobacter (25.6%). In total, 19 C. lari and 1 C. jejuni strains were isolated. C. lari isolates found in this study belong to 13 sequence types (STs), and 9 of them are newly described in this paper. Two out of the four previously described C. lari STs that were found in this study were previously found in human stool. The only C. jejuni isolate was found to be sequence type 1268, which belongs to ST-1275 clonal complex that is almost exclusively found in seabirds and can sporadically cause infection in humans. Regarding the obtained results, introducing surveillance of thermotolerant Campylobacter in shellfish in the Republic of Croatia is advised as an improvement for public health safety.

Orientador: Flávio Dias Passos Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia Resumo: O Brasil aderiu ao "Tratado Antártico" em 1975, e desde 1982 mantém o "Programa Antártico Brasileiro. A partir de 1984 as pesquisas brasileiras se concentraram na Baía do Almirantado, na Ilha Rei George, onde se localiza a base do país. A Baía do Almirantado foi eleita uma "Área Antártica Especialmente Gerenciada" pelas Partes Consultivas do Tratado Antártico e trata-se de um local representativo do ecossistema costeiro antártico, principalmente em termos de distribuição e composição de espécies. Lá os pesquisadores tem estudado a fauna bentônica da região, entre eles os Mollusca, que são abundantes e importantes no estudo dos processos que determinam a estrutura e o funcionamento das comunidades bentônicas marinhas. Este estudo se focou na classe Bivalvia, provendo um novo material de referência para identificação destes animais, e mais especificamente daqueles da Baía do Almirantado, apresentando-se como um guia ilustrado, com descrições detalhadas das conchas dessas espécies. Além disso, dados de distribuição geográfica e batimétrica foram reunidos para uma análise dessa fauna, na tentativa de qualificar a importância da região das Ilhas Shetland do Sul como um local estratégico para estudos em biogeografia. Foram identificadas 39 espécies de 18 famílias distintas, e seus dados de biologia, distribuição batimétrica e geográfica reunidos. As famílias mais representativas foram Philobryidae, Nuculanidae e Lasaeidae, contabilizando 15 espécies. As regiões com mais espécies em comum com a área estudada foram o Estreito de Magalhães, Ilha Georgia do Sul, Mar de Weddell, Península Antártica e sul do Chile; regiões notáveis pela riqueza de Bivalvia. As famílias mais largamente distribuídas, encontradas neste estudo, foram LImidae e Carditidae; e as mais restritas foram Siliculidae e Nuculanidae. A espécie com maior distribuição foi Cyclocardia astartoides, e as mais restritas Ennucula georgiana e Mysella narchii. As espécies encontradas se concentram nas profundidades até 1000 m, com seu número caindo para menos da metade além disso. Apenas seis espécies ocorrendo além dos 2000 m: Yoldiella profundorum, Limopsis marionensis, Limopsis lilliei, Adacnarca nitens, Limatula pygmaea e Cyclocardia astartoides. Este estudo demonstram a região da Baía do Almirantado como abrigo de uma fauna de Bivalvia composta por espécies estritamente antárticas, e outras que ocorrem ao norte da Convergência Antártica; sendo assim uma região importante para o estudo da distribuição destes animais Abstract: Brazil abided to the "Antarctic Treaty" in 1975, and since 1982 maintains the "Brazilian Antarctic Program". As from 1984 the Brazilian researches focused on Admiralty Bay, in King George Island, where the country?s Antarctic base is located. Admiralty Bay was elected a "Antarctic Especially Managed Area" by the Antarctic Treaty Consultative Parties and is a representative place for the Antarctic coastal ecosystem, especially in views of species distribution and composition. In there researchers have been studying the regional benthic fauna, amidst it the Mollusca, abundant and important animals for the study of determinant process in the structure and operation of the marine benthic community. The present study focused on the class Bivalvia, providing a new reference source for identification of the group, and specifically for those of Admiralty Bay, presented as an illustrated guide with detailed shell descriptions for all the species found. Furthermore, data on geographic and bathymetric distribution were gathered for an analysis of this fauna, in attempt to qualify the importance of the South Shetland Islands as a strategic place for studies on biogeography. Thirty-nine species, of 18 distinct families, were identified, and their biological, geographical and bathymetrical data gathered. The most representative families were Philobryidae, Nuculanidae and Lasaeidae, counting 15 species in sum. The geographic regions with more species in common with the studied area were Strait of Magellan, South Georgia Island, Weddell Sea, Antarctic Peninsula and Southern Chile; notable regions for Bivalvia richness. The families found with the largest geographic distribution were Limidae and Carditidae, and the most restricted ones were Siliculidae and Nuculanidae. The species with largest geographical distribution was Cyclocardia astartoides, while the most restricted were Ennucula georgiana and Mysella narchii. The species found in this study are concentrated in depths until 1000 m, beyond that their number shortens to less than half. Only six occur deeper than 2000 m: Yoldiella profundorum, Limopsis marionensis, Limopsis lilliei, Adacnarca nitens, Limatula pygmaea and Cyclocardia astaroides. The present study shows Admiralty Bay as shelter to a Bivalvia fauna with strictly Antarctic species and northern ones, common north to the Antarctic Convergence, thus being an important place for studying the distribution of these animals Mestrado Ecologia Mestre em Ecologia

The objectives of this study were to present data on the presence of Salmonella enterica subsp. enterica and on the enumeration of Escherichia coli and faecal coliforms respectively in different species of bivalve molluscs and seawater and to conduct a retrospective evaluation to assess the capacity of E. coli in molluscs and faecal coliforms and S. enterica subsp. enterica in sea and brackish water to predict the presence of S. enterica subsp. enterica in bivalve molluscs, and therefore, the risk of exposure for consumers. Data were collected from 4972 seawater samples and 5785 live bivalve molluscs samples (2877 Ruditapes philippinarum , 2177 Mytilus galloprovincialis, 256 Chamelae gallina and 475 C. gigas and O. edulis ) collected in the molluscs production area of Ferrara, Northern Italy, from 1997 to 2015. An overall S. enterica subsp. enterica occurrence of 2.2% was reported in water and molluscs, with percentages varying depending on the type of sample and on the classification areas. All the 237 Salmonella strains were identified as genus Salmonella and a total of 53 different serovars were observed. Significant associations between the fecal indicators and presence of S. enterica subsp. enterica were observed both applying EU and USA criteria, but, it should be noted that the EU approach seems to be more stringent achieving the goal of identifying the most critical batches (94 out of the 100) whereas, following the USA approach, a not negligible and higher number of batches compliant for faecal coliforms but contaminated by S. enterica subsp. enterica has to be mentioned. In any case, the faecal indicators E. coli in molluscs and faecal coliforms in seawaters reflect only in part the presence of S. enterica subsp. enterica in molluscs and the consequent potential risk for consumers. Microbiological evaluation of seawaters seems to have a minor impact into the prediction of S. enterica subsp. enterica presence in molluscs.

The Toll/interleukin-1 receptor (TIR) domain has a fundamental role in the innate defence response of plants, vertebrate and invertebrate animals. Mostly found in the cytosolic side of membrane-bound receptor proteins, it mediates the intracellular signalling upon pathogen recognition via heterotypic interactions. Although a number of TIR-domain-containing (TIR-DC) proteins have been characterized in vertebrates, their evolutionary relationships and functional role in protostomes are still largely unknown. Due to the high abundance and diversity of TIR-DC proteins in bivalve molluscs, we investigated this class of marine invertebrates as a case study. The analysis of the available genomic and transcriptomic data allowed the identification of over 400 full-length sequences and their classification in protein families based on sequence homology and domain organization. In addition to TLRs and MyD88 adaptors, bivalves possess a surprisingly large repertoire of intracellular TIR-DC proteins, which are conserved across a broad range of metazoan taxa. Overall, we report the expansion and diversification of TIR-DC proteins in several invertebrate lineages and the identification of many novel protein families possibly involved in both immune-related signalling and embryonic development.

Microplastic content (MPs) in mussels (Mytilus spp.) from two areas of the north coast of Spain was measured for the first time. Additionally, a comparison of microplastic levels observed in mussels digested with nitric acid and with potassium hydroxide was carried out. The average microplastic concentration in mussels digested with nitric acid was significantly lower than that observed in mussels digested with potassium hydroxide (p < 0.05). The average concentration of microplastics in mussels from the Cantabrian Sea (2.55±2.80 MPs g–1 WW) was slightly higher than that in mussels from the Ria of Vigo (1.59±1.28 MPs g–1 WW). Both in the Ria of Vigo and in the Cantabrian Sea the observed pattern of pollution was fitted to the one expected. Consequently, mussels have been confirmed as suitable sentinel organisms for microplastic pollution. Se midió por primera vez el contenido en microplásticos (MPs) presente en mejillones (Mytilus spp.) procedentes de dos áreas de la costa del norte de España. Además, se llevó a cabo una comparación de los niveles de microplásticos observados en mejillones digeridos con ácido nítrico y con hidróxido de potasio. La concentración promedio de microplásticos que se observó en los mejillones digeridos con ácido nítrico fue significativamente inferior a la observada en los mejillones digeridos con hidróxido de potasio (p

Human-induced climate change and ocean acidification are global environmental phenomena with a common driver: anthropogenic emissions of carbon dioxide. Both processes potentially threaten the Mediterranean bivalve mollusc aquaculture sector, which is economically relevant to several regions and countries. Detrimental effects on bivalve mollusc species might arise from the associated increase in sea surface temperature, pH reduction, higher frequency of extreme climatic events, and possible synergies with other nonclimatic stressors, such as harmful algal blooms and mollusc diseases. This paper presents the results of a questionnaire-based study of Mediterranean bivalve mollusc producers from 12 coastal regions and six countries, the latter including those with the highest production share in the Mediterranean region. This study aims to assess knowledge and perception of threat of climatic and nonclimatic environmental stressors within the Mediterranean aquaculture industry. Furthermore, it collects information about the (geographical) impacts of summer heat waves and ocean acidification. The results suggest that ocean acidification is still a relatively unknown phenomenon and generally poorly understood. Moreover, it is considered a secondary threat compared with other pressures. Summer heat waves are presently perceived as the highest threat, having been observed in a majority of the studied production sites in past years, with effects on seed (spat), adult mortality, and byssus attachment.

Despite the large number of animal complete mitochondrial genomes currently available in public databases, knowledge about mitochondrial genomics in invertebrates is uneven. This paper reports, for the first time, the complete mitochondrial genome of the grooved carpet shell, Ruditapes decussatus, also known as the European clam. Ruditapes decussatus is morphologically and ecologically similar to the Manila clam Ruditapes philippinarum, which has been recently introduced for aquaculture in the very same habitats of Ruditapes decussatus, and that is replacing the native species. Currently the production of the European clam is almost insignificant, nonetheless it is considered a high value product, and therefore it is an economically important species, especially in Portugal, Spain and Italy. In this work we: (i) assembled Ruditapes decussatus mitochondrial genome from RNA-Seq data, and validated it by Sanger sequencing; (ii) analyzed and characterized the Ruditapes decussatus mitochondrial genome, comparing its features with those of other venerid bivalves; (iii) assessed mitochondrial sequence polymorphism (SP) and copy number variation (CNV) of tandem repeats across 26 samples. Despite using high-throughput approaches we did not find evidence for the presence of two sex-linked mitochondrial genomes, typical of the doubly uniparental inheritance of mitochondria, a phenomenon known in ∼100 bivalve species. According to our analyses, Ruditapes decussatus is more genetically similar to species of the Genus Paphia than to the congeneric Ruditapes philippinarum, a finding that bolsters the already-proposed need of a taxonomic revision. We also found a quite low genetic variability across the examined samples, with few SPs and little variability of the sequences flanking the control region (Largest Unassigned Regions (LURs). Strikingly, although we found low nucleotide variability along the entire mitochondrial genome, we observed high levels of length polymorphism in the LUR due to CNV of tandem repeats, and even a LUR length heteroplasmy in two samples. It is not clear if the lack of genetic variability in the mitochondrial genome of Ruditapes decussatus is a cause or an effect of the ongoing replacement of Ruditapes decussatus with the invasive Ruditapes philippinarum, and more analyses, especially on nuclear sequences, are required to assess this point.

Algal biotoxins, chemical compounds produced by some microscopic algae, constitute the phytoplankton. The mussels, feeding on phytoplankton, can accumulate these compounds to become themselves toxic. There have been several cases of food poisoning by consumption of contaminated shellfish. Such food poisoning have pushed our health care system to provide monitoring of shellfish in the framework of the monitoring plans carried out by AASSLL. In this paper we report the results obtained monitoring the presence of ASP (Amnesic Shellfish Poisoning) biotoxins, like domoic acid (DA) and its isomers, produced by Pseudonitzschia algae. The analysis were carried out by using both the HPLC-UV official method and an experimental method performed with a Time of Flight mass spectrometer (ESI-TOF). The 100% of samples analysed by the official method have always been below the limits of sensitivity (except one sample), the 65% of samples analysed by ESI-TOF, showed the presence of domoic acid.

8 páginas, 6 figuras, 3 tablas., Metallothionein (MT) and other biomarker levels were measured in Scrobicularia plana clams to assess pollution of the Guadalquivir Estuary possibly affected by metals released from Aznalcóllar pyrite mine in 1998. After optimizing reagent concentrations for monobromobimane derivatization, MT levels were quantified by reversed-phase high-performance liquid chromatography coupled to fluorescence detection (RP-HPLC-FD) in heated or unheated digestive gland extracts and compared to those obtained by differential pulse polarography (DPP). MT content assayed by RP-HPLC-FD in unheated samples was higher than that obtained by DPP and correlated better with metals and anti-oxidant activities. MT assay by RP-HPLC-FD in unheated extracts would be preferable for assessing metal pollution, due to its greater sensitivity and specificity. In addition to MT induction, glyoxalase II inhibition was well correlated with metal contents. Our results suggest that metals at the estuary do not originate from Aznalcóllar spill, but from those carried along by the river and deposited at its concave bank., This work was funded by grant CMT2006-08960-C02 from the Spanish Ministry of Education and Science, a grant from the Doñana 2005 Program, and grants CVI-151 and FQM-141 from the Andalusian Research Plan. A.R.-R. had a predoctoral fellowship from the Spanish Ministry of Education and Science.

We originally developed a functional assay for the detection of yessotoxins (YTX) based on its capacity to induce dose-dependent changes in cellular levels of two marker proteins, consisting of E-cadherin and an E-cadherin fragment (ECRA 100 ) in epithelial cells. The procedure is time-consuming and we have shortened it by a slot blot format, using antibodies recognizing two different epitopes of E-cadherin (HECD-1 and C20820), thereby discriminating those markers. The best performing membrane under our conditions, in terms of binding capacity and even absorption of proteins, was a positively charged nylon membrane. Treatment of the membrane with 0.5 μg of Ab/ml was appropriate for maximal detection of antigens by our slot blot procedure with both HECD-1 and C20820 antibodies. The treatment of cells with YTX, resulting in a relative increase in the cellular levels of ECRA 100 , led to a dose-dependent increase of the signal detected by Ab HECD-1 without a concomitant increase in the signal detected by Ab C20820 in our slot blot format, and the concentrations of YTX were correlated to both the increase of the signal detected through Ab HECD-1 and to the decrease in the ratio of the signals obtained with the two Abs (C20820 over HECD-1). Upon analyses of extracts from cells treated with shellfish samples, we could detect and quantify YTX in naturally contaminated materials. The slot blot format of our functional assay allows a substantial shortening of its analytical step (about seven hr, as compared to the two working days of the original method), providing YTX measurements that are accurate but show large standard deviations.

Herpes-like viral infections have been reported in different bivalve mollusc species throughout the world. High mortalities among hatchery-reared larvae and juveniles of different bivalve species have been associated often with such infections. The diagnosis of herpes-like viruses in bivalve molluscs has been performed traditionally by light and transmission electron microscopy. The genome sequencing of one of these viruses, oyster herpesvirus 1 (OsHV-1), allowed the development of DNA-based diagnostic techniques. The polymerase chain reaction (PCR) has been used for the detection of OsHV-1 DNA in bivalve molluscs at different development stages. In addition, the PCR used for detection of OsHV-1 has also allowed the amplification of DNA from an OsHV-1 variant. The literature on DNA extraction methods, primers, PCR strategies, and confirmatory procedures used for the detection and identification of herpesviruses that infect bivalve molluscs are reviewed. (c) 2006 Elsevier B.V. All rights reserved.

The aim of the present survey was to investigate the correct enforcement of the Community rules on the labelling and marketing of bivalve and gastropod molluscs retailed in Sardinia, Italy between 2009 and 2013. A total of 1500 packages and labels for live bivalve and gastropod molluscs were considered. A total of 375 labels (25%) presented non-compliance concerning the wrong trade name and additional wrong or missing information. The highest percentage of anomalous labels has been detected in small-scale retail shops (35%) and open-air markets (25%) compared with the big retailing chains (20%). The 5% of packages were not in compliance with the European Community rules on packaging of bivalve and gastropod molluscs. The high percentage of non-compliance with the European regulations on labelling results is a strong limitation for the consumers and highlights the need to improve the control system about labelling of seafood products.

22 pages, 1 figure, 1 plate, 2 tables., The genus Perkinsus includes protistan parasites infecting marine molluscs throughout the world, some of which are associated with mass mortalities. Life cycle involves vegetative proliferation within the host, by which a cell named trophozoite undergoes successive bipartitioning. Other stages have been observed in vitro or in vivo, depending on the species: hypnospore, zoosporangium and zoospore. Molecular taxonomy supports a close affinity between dinoflagellates and Perkinsus spp. Six species of Perkinsus are currently considered valid: P. marinus, P. olseni, P. qugwadi, P. chesapeaki, P. andrewsi and P. mediterraneus. Histology and, above all, incubation of host tissues in Ray's fluid thioglycollate medium (RFTM) are classic diagnostic methods. In addition, more sensitive and quicker molecular diagnostic techniques based on either immunoassays or PCR have been developed for Perkinsus spp. Epizootiological studies have shown a marked influence of water temperature and salinity on P. marinus infection in oysters Crassostrea virginica, thus determining parasite geographical range and temporal disease dynamics (seasonality). In vitro cultures have been established for four Perkinsus spp. Immune response to infection varies depending on host and involves phagocytosis or encapsulation of the parasite cells by host haemocytes. A polypeptide is secreted by clam Tapes philippinarum haemocytes that could kill the parasite. In vitro cultured P. marinus cells secrete proteases that are likely involved in degradation of host tissues. P. marinus can suppress the toxic oxygen radicals produced by host haemocytes. In addition to host death, sublethal effects caused by Perkinsus spp. (reduction of fecundity, growth, and condition) may have significant ecological and economic implications. Various strategies have been assayed to mitigate the consequences of P. marinus epizootics on the oyster industry: modifications of management/culture procedures, selective breeding to obtain resistant oyster strains, and the use of triploid oysters and allochthonous oyster species. Some chemotherapeutants have been proved to inhibit or kill parasite cells in vitro.

To the Editor: Bivalve mollusks (shellfish), such as mussels and oysters, are filter feeders; they concentrate microorganisms of human and animal origin (up to 100×) from the surrounding environment. Several recent reports have linked the incidence of human infection with hepatitis E virus (HEV) to consumption of undercooked pork, game products, and shellfish (1,2). Infectious HEV has been found in swine manure and wastewater (3); therefore, application of manure to land and subsequent runoff could contaminate coastal water, leading to contamination of shellfish and, subsequently, possible human infection. Because they are filter feeders, bivalve mollusks are biologically relevant sentinels and can indicate potential pathogens that are contaminating the environment. It is essential to ensure that this sustainable resource of coastal areas, where mussels and oysters are farmed or collected wild, is not subjected to environmental contamination that could lead to public health risks. Risk management for bivalve mollusks, aimed at control of fecal pollution, relies heavily on the use of Escherichia coli as an indicator of fecal (sewage) contamination and is enacted under European food regulations (Regulation 854/2004, www.cefas.co.uk/media/455777/extract_reg_no_854_2004.pdf). However, although these regulations probably reduce the number of infections, especially bacterial infections, they are not viewed as adequately controlling the risk for viral infections. Specific risks are posed by the robustness of viruses in the environment and the different behavior of viruses within bivalve mollusks compared with behavior within bacterial fecal indicators. HEV is deemed to be inactivated during processing procedures used to prepare mussels for consumption; however, HEV is only 50% inactivated at 56°C and 96% at 60°C for 1 hour, it is stable when exposed to trifluorotrichloroethane, and it is resistant to inactivation by acidic and alkaline conditions (4). Most shellfish are usually eaten raw, but viable virus can also pose a risk to public health in shellfish that are lightly steamed or preserved by smoking and/or in acetic acid. Indeed, a recent study by the Food Standards Agency, in which >800 oyster samples from 39 growing beds in the United Kingdom were collected and screened during 2009–2011, found norovirus at low levels in at least 76% of oysters (5). Other studies identified hepatitis A virus and norovirus in shellfish production areas and in ready-to-eat products in the United Kingdom (1,6). In fact, depuration experiments demonstrated no decrease in titers against hepatitis A virus over a 23-hour cleansing period (7). In addition, acute HEV infection attributed to consumption of shellfish was diagnosed for 33 passengers who recently returned from a cruise (2). However, data have been restricted to questionnaires implicating consumption of shellfish as a source of transmission; no follow-up analyses of the contaminated foodstuff have been conducted. Thus, possible transmission routes for HEV remain poorly studied in the United Kingdom (2). To determine whether HEV is present in mussels collected locally for human consumption, we examined 48 mussels from 5 tidal locations in Scotland. We collected closed mussels from the west coast of Scotland (11 at Lunderston Bay and 28 at Ardrossan) and the east coast of Scotland (9 at Stannergate, Dundee; Ferryden, Montrose; and the Ythan Estuary at Newburgh). The site at Ardrossan was near a slaughterhouse and a meat preparation purification plant that processes pigs. The plant was considered a potential source of contamination, and mussels were collected in a 10-m2 area around an outfall (drain/sewage pipe) directly in line with the processing plant. A total of 36 (92%) of the 39 mussels from the west coast were positive by PCR for HEV, and 5 (55%) of the 9 from the east coast were positive. The mean value of HEV RNA detected in the samples was 4.25 log10 IU/mL (range 3.73–5.2 log10 IU/mL), and the assay was validated by using the current candidate HEV World Health Organization standard (http://whqlibdoc.who.int/hq/2011/WHO_BS_2011.2175_eng.pdf). Phylogenetic analysis showed that most bivalve mollusk sequences clustered with HEV genotype 3 from humans and swine (Figure; Technical Appendix). Also, HEV sequences isolated specifically from a UK human source corresponded with sequences isolated from the bivalve mollusks. The presence of a swine-like HEV genotype 3 in freshwater bivalve mollusks has also been reported in Japan and South Korea (1,9). Figure Phylogenetic analysis of HEV open reading frame 2 sequences isolated from Mytilus spp. RNA was isolated from 50–100 mg of digestive gland or gill. Tissue was homogenized in 300 μL phosphate-buffered saline, and viral RNA was isolated by ... Worldwide, an estimated 40,000 persons die and another 40,000 experience long-term disability as a result of consuming raw or undercooked shellfish (10). This study, demonstrating the presence of HEV in mussels collected locally in Scotland for human consumption, raises concern as to whether these shellfish are a potential source of infection, as reported (2). The association between environmental contamination with HEV and possible transmission by eating shellfish warrants investigation. Technical Appendix: ClustalW alignment of sequences used to generate the phylogenetic tree in the Figure. Click here to view.(218K, pdf)

Biology and population dynamics of the suspension-feeding wedge clam Donax trunculus (Linnaeus, 1758) were studied for 13 months (November 1994–April 1996) along the Italian Southern Adriatic coast near the Lagoon of Lesina. Specimens were found at depths between 0 and 2 m, mainly in fine grain bottoms. The spatial coastal distribution showed an intraspecific segregation between young and adult wedge clams. A unimodal recruitment (length >4 mm) occurred in winter (December–February). Length frequency distributions were used to determine age and growth rate. Three year classes were regularly observed and their growth pattern defined. The population showed a maximum length of 37 mm and a longevity of 4 years. Analysis of seasonal variations in the reproductive cycle showed that gametogenesis occurred in spring in females. After the spawning season (March–July) females of D. trunculus remained in a resting stage from August to January.

Tetrodotoxins (TTXs) are traditionally associated with the occurrence of tropical Pufferfish Poisoning. In recent years, however, TTXs have been identified in European bivalve mollusc shellfish, resulting in the need to assess prevalence and risk to shellfish consumers. Following the previous identification of TTXs in shellfish from southern England, this study was designed to assess the wider prevalence of TTXs in shellfish from around the coast of the UK. Samples were collected between 2014 and 2016 and subjected to analysis using HILIC-MS/MS. Results showed the continued presence of toxins in shellfish harvested along the coast of southern England, with the maximum concentration of total TTXs reaching 253 µg/kg. TTX accumulation was detected in Pacific oysters (Crassostrea gigas), native oysters (Ostrea edulis) common mussels (Mytilus edulis) and hard clams (Mercenaria mercenaria), but not found in cockles (Cerastoderma edule), razors (Ensis species) or scallops (Pecten maximus). Whilst the highest concentrations were quantified in samples harvested during the warmer summer months, TTXs were still evident during the winter. An assessment of the potential causative factors did not reveal any links with the phytoplankton species Prorocentrum cordatum, instead highlighting a greater level of risk in areas of shallow, estuarine waters with temperatures above 15 °C.

Despite the large number of animal complete mitochondrial genomes currently available in public databases, knowledge about mitochondrial genomics in invertebrates is uneven. This paper reports, for the first time, the complete mitochondrial genome of the grooved carpet shell,Ruditapes decussatus, also known as the European clam.Ruditapes decussatusis morphologically and ecologically similar to the Manila clamRuditapes philippinarum, which has been recently introduced for aquaculture in the very same habitats ofRuditapes decussatus, and that is replacing the native species. Currently the production of the European clam is almost insignificant, nonetheless it is considered a high value product, and therefore it is an economically important species, especially in Portugal, Spain and Italy. In this work we: (i) assembledRuditapes decussatusmitochondrial genome from RNA-Seq data, and validated it by Sanger sequencing; (ii) analyzed and characterized theRuditapes decussatusmitochondrial genome, comparing its features with those of other venerid bivalves; (iii) assessed mitochondrial sequence polymorphism (SP) and copy number variation (CNV) of tandem repeats across 26 samples. Despite using high-throughput approaches we did not find evidence for the presence of two sex-linked mitochondrial genomes, typical of the doubly uniparental inheritance of mitochondria, a phenomenon known in ∼100 bivalve species. According to our analyses,Ruditapes decussatusis more genetically similar to species of the Genus Paphia than to the congenericRuditapes philippinarum, a finding that bolsters the already-proposed need of a taxonomic revision. We also found a quite low genetic variability across the examined samples, with few SPs and little variability of the sequences flanking the control region (Largest Unassigned Regions (LURs). Strikingly, although we found low nucleotide variability along the entire mitochondrial genome, we observed high levels of length polymorphism in the LUR due to CNV of tandem repeats, and even a LUR length heteroplasmy in two samples. It is not clear if the lack of genetic variability in the mitochondrial genome ofRuditapes decussatusis a cause or an effect of the ongoing replacement ofRuditapes decussatuswith the invasiveRuditapes philippinarum, and more analyses, especially on nuclear sequences, are required to assess this point.

Water pollution represents a threat of increasing importance to human health. Bivalve mollusks are filter-feeding organisms that can accumulate chemical and microbiological contaminants in their tissues from very low concentrations in the water or sediments. Consumption of contaminated shellfish is one of the main causes of seafood poisoning. Thus, marine bivalves are normally depurated in sterilized seawater for 48. h to allow the removal of bacteria. However, this depuration time might be insufficient to eliminate chemical contaminants from their tissues. We have developed a novel technology that accelerates up to fourfold the excretion rate of xenobiotics in bivalves by treatment with the antioxidant and glutathione (GSH) pro-drug N-acetylcysteine (NAC) during the depuration period. NAC improved dose-dependently the detoxification of the organophosphate (OP) pesticide fenitrothion in the mussel Mytilus galloprovincialis, diminishing its levels up to nearly a hundred fold compared to conventional depuration, by enhancing the glutathione S-transferase (GST) activity and inducing the GSH anabolism (GSH synthesis and reduction by glutathione reductase). Notably, this induction in GSH anabolism and GST activity was also observed in uncontaminated bivalves treated with NAC. As the GSH pathway is involved in the detoxification of many pollutants and biotoxins from harmful algal blooms, we validated this proof of principle in king scallops (. Pecten maximus) that naturally accumulated the amnesic shellfish poisoning (ASP) toxin domoic acid. We illustrate here a method that enhances the elimination of organic contaminants in shellfish, opening new avenues of depuration of marine organisms. © 2014., S.P-L. was partially supported by a Postdoctoral Fellowship from Generalitat Valenciana (Conselleria de Empresa, Universidad y Ciencia, Spain, CTBPDC/2003/035). E.B. was supported by a pre-doctoral fellowship from University Jaume I. This work has been developed in the framework of the Research Unit of Marine Ecotoxicology IATS (CSIC)-IUPA (UJI) and was supported by a grant from the Spanish Government (Ministerio de Educación y Ciencia, PTR95-0991.OP) to J.B.P. and R.S. and from Generalitat Valenciana as a research group of excellence (PROMETEO/2009/054).

Edible lamellibranch molluscs can be involved in foodborne disease and infections of varying severity. They are filter feeding animals able to retain and concentrate in their organism bacteria, parasites, viruses and biotoxins marine algae present in their external environment. Major shellfish harvesting and relaying areas from different areas in Sardinia region were defined and studied by analysing different physicochemical parameters in the water and the levels of Escherichia coli (E. coli), Norovirus (NoVs) genogroup I (NoVGI), NoVs genogroup II (NoVGII) and hepatitis A virus (HAV) in the shellfish harvested and farmed from 2009 to 2011. During that period the identification of the viral agents was carried out by one step real-time reverse transcriptase-polymerase chain reaction and Escherichia coli according to ISO TS 16649-3:2005 standard method. A total of 1266 shellfish samples were tested for NoVGI, NoVGII, HAV and faecal indicators. Norovirus contamination was found in 337 samples (26.6%); only one sample of mussels was positive for HAV (0.08%); while E. coli prevalence was 3.8% in shellfish. The probability of observing shellfish samples positive for NoVs, HAV and E. coli presence was associated with harvesting, growing and relaying areas, period of sampling, environmental parameters, animal species (P

NOTICE: this is the author’s version of a work that was accepted for publication in Toxicon. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Toxicon, Volume 65, April 2013, Pages 81–89, doi:10.1016/j.toxicon.2013.01.010, The relationship between azaspiracid shellfish poisoning and a small dinoflagellate, Azadinium spinosum, has been shown recently. The organism produces AZA1 and -2, while AZA3 and other analogues are metabolic products formed in shellfish. We evaluated whether mussels were capable of accumulating dissolved AZA1 and -2, and compared the toxin profiles of these mussels at 24 h with profiles of those exposed to live or lysed A. spinosum. We also assessed the possibility of preparative production of AZA metabolites by exposing mussels to semi-purified AZA1. We exposed mussels to similar concentration of AZAs: dissolved AZA1 + 2 (crude extract) at 7.5 and 0.75 μg L−1, dissolved AZA1+2 (7.5 μg L−1) in combination with Isochrysis affinis galbana, and lysed and live A. spinosum cells at 1 × 105 and 1 × 104 cell mL−1 (containing equivalent amounts of AZA1 + 2). Subsequently, we dissected and analysed digestive glands, gills and remaining flesh. Mussels (whole flesh) accumulated AZAs to levels above the regulatory limit, except at the lower levels of dissolved AZAs. The toxin profile of the mussels varied significantly with treatment. The gills contained 42–46% and the digestive glands 23–24% of the total toxin load using dissolved AZAs, compared to 3–12% and 75–90%, respectively, in mussels exposed to live A. spinosum. Exposure of mussels to semi-purified AZA1 produced the metabolites AZA17 (16.5%) and AZA3 (1.7%) after 4 days of exposure, but the conversion efficiency was too low to justify using this procedure for preparative isolation.

Okadaic acid (OA) and dinophysistoxins (DTXs) are the main toxins responsible for diarrhetic shellfish poisoning (DSP) intoxications during harmful algal blooms (HABs). Although the genotoxic and cytotoxic responses to OA have been evaluated in vitro, the in vivo effects of these toxins have not yet been fully explored. The present work fills this gap by evaluating the in vivo effects of the exposure to the DSP-toxin-producing dinoflagellate Prorocentrum lima during the simulation of an early HAB episode in the mussel Mytilus galloprovincialis. The obtained results revealed that in vivo exposure to this toxic microalgae induced early genotoxicity in hemocytes, as a consequence of oxidative DNA damage. In addition, the DNA damage observed in gill cells seems to be mainly influenced by exposure time and P. lima concentration, similarly to the case of the oxidative damage found in hemocytes exposed in vitro to OA. In both cell types, the absence of DNA damage at low toxin concentrations is consistent with the notion suggesting that this level of toxicity does not disturb the antioxidant balance. Lastly, in vivo exposure to growing P. lima cell densities increased apoptosis but not necrosis, probably due to the presence of a high number of protein apoptosis inhibitors in molluscs. Overall, this work sheds light into the in vivo genotoxic and cytotoxic effects of P. lima. In doing so, it also demonstrates for the first time the potential of the modified (OGG1) comet assay for assessing oxidative DNA damage caused by marine toxins in marine invertebrates. Ministerio de Economía y Competitividad; AGL2012-30897

Spatial variations in carbon and nitrogen stable isotopes (delta C-13 and delta N-15) of benthic filter feeders were investigated on an inshore-offshore gradient (0-250 km) along the continental shelf of the northern Bay of Biscay (NE Atlantic Ocean). delta C-13 and delta N-15 values were measured in muscle tissues of four filter-feeding mollusc species (epifaunal: Pecten maxim us, Aequipecten opercularis; infaunal: Glycymeris glycymeris, Venus casina) and in benthic particulate organic matter along a corresponding water-depth gradient from 6 to 220 m. All four species showed a decreasing pattern of muscle delta C-13 and delta N-15 values with increasing depth. At the Ushant front (similar to 130 m water depth), where there is a decrease in both bottom water chlorophyll a and suspended particulate matter, muscle delta C-13 and delta N-15 values decreased in all species. Although delta C-13 values of infaunal clams initially decreased at 30 m depth, delta C-13 values of epifaunal scallops decreased around 120 m depth, far below the expected depth reduction in microphytobenthic production suggesting that carbon isotopes might not simply track microphytobenthic utilization. The difference between infaunal and epifaunal bivalve stable isotope values may reflect differences in feeding strategies. Muscle delta N-15 values at the deepest stations (similar to 2 parts per thousand) were lower than expected considering the typical trophic enrichment value of 3-4 parts per thousand between prey and consumers. These low delta N-15 values may result from low metabolic rates and suggest the classic trophic enrichment may not hold true in species inhabiting deep waters. Stable isotopes in benthic filter feeders can reveal much information regarding their ecology and environment, but are not straightforward recorders of stable isotope baseline variations as is often assumed.

8 páginas, 1 figura, 3 tablas. VIII Congreso Nacional de Acuicultura: Acuicultura y desarrollo Sostenible (2001, 22-25 mayo, Santander), [EN] We present a histomorphological description of the digestive tract of the oyster Crassostrea angulata (Lamarck, 1819), as well as a histochemical study of its carbohydrate distribution. The study shows that, in general, glycogen is found in the connective tissue, and neutral mucopolysaccharides/glycoproteins and/or acid mucosubstances in the epithelium and basal cell layers. Glycogen was not detected in the digestive gland, possibly because of its mobilization to the connective tissue for reproduction., [ES] Se realiza una descripción histomorfológica del aparato digestivo del ostión Crassostrea angulata (Lamarck, 1819) y se pone de manifiesto la distribución de carbohidratos mediante técnicas histoquímicas. La pauta general observada es la presencia de glucógeno en el tejido conjuntivo y de mucopolisacáridos/glicoproteínas neutras y/o ácidas en las membranas basales y el epitelio. En la glándula digestiva no se observa glucógeno debido, posiblemente, a su movilización hacia el tejido conjuntivo para su posterior uso con fines reproductivos.