Search

Climate change and size-selective overexploitation can alter fish size and growth, yet our understanding of how and to what extent is limited due to a lack of long-term biological data from wild populations. This precludes our ability to effectively forecast population dynamics and support sustainable fisheries management. Using modern, archived, and archaeological vertebrae dimensions and growth rings of one of the most intensely exploited populations, the eastern Atlantic and Mediterranean bluefin tuna (Thunnus thynnus, BFT), we estimated catch-at-size and early-life growth patterns from the 3rd century bce to the 21st century ce to understand responses to changes in its environment. We provide novel evidence that BFT juvenile growth increased between the 16th–18th, 20th, and 21st centuries, and is correlated with a warming climate and likely a decrease in stock biomass. We found it equally plausible that fisheries-induced evolution has acted to increase juvenile BFT growth, driving earlier maturation as a result of size-selective exploitation. Coincidently, we found limited evidence to suggest a long history of large ( >200 cm FL) BFT capture. Instead, we found that the catch-at-size of archaeological BFT was relatively small in comparison with more intensive, 20th and 21st century tuna trap fisheries which operated further from shore. This complex issue would benefit from studies using fine-scale biochronological analyses of otoliths and adaptation genomics, throughout the last century especially, to determine evolutionary responses to exploitation, and further disentangle the influence of temperature and biomass on fish growth.

Three specimens of Silver John dory, Zenopsis conchifer, (Lowe, 1852) were observed for the first time in the Ligurian Sea and northern Tyrrhenian Sea (western Mediterranean), one in 2020 and two in 2021. This is the fifth record (up to ten individuals) of Z. conchifer in the Mediterranean Sea, which occurred 11 years after the last observation in 2010 in the southern Tyrrhenian Sea. The present study reports the northernmost record of the species in the western Mediterranean Sea, indicating a potential range expansion of the distribution of this Atlantic species across the area. Morphometric, meristic and biological data of the three specimens are provided and compared with previous published records.

Aim: Determine the evolutionary origin of the heretofore poorly characterized contemporary Great White Shark (GWS; Carcharodon carcharias) of the Mediterranean Sea, using phylogenetic and dispersal vicariance analyses to trace back its global palaeo-migration pattern. Location: Mediterranean Sea. Taxon: Carcharodon carcharias. Methods: We have built the largest mitochondrial DNA control region (CR) sequence dataset for the Mediterranean GWS from referenced historical jaws spanning the 19th and 20th centuries. Mediterranean and global GWS CR sequences were analysed for genetic diversity, phylogenetic relationships and divergence time. A Bayes factor approach was used to assess two scenarios of GWS lineage divergence and emergence of the Mediterranean GWS line using fossil records and palaeo-geographical events for calibration of the molecular clock. Results: The results confirmed a closer evolutionary relationship between Mediterranean GWS and populations from Australia–New Zealand and the North-eastern Pacific coast rather than populations from South African and North-western Atlantic. The Mediterranean GWS lineage showed the lowest genetic diversity at the global level, indicating its recent evolutionary origin. An evaluation of various divergence scenarios determined the Mediterranean GWS lineage most likely appeared some 3.23 million years ago by way dispersal/vicariance from Australian/Pacific palaeo-populations. Main conclusion: Based on the fossil records, phylogeographic patterns and divergence time, we revealed that the Mediterranean GWS population originated in the Pliocene following the Messinian Salinity Crisis. Colonization of the Mediterranean by GWS likely occurred via an eastward palaeo-migration of Australian/eastern Pacific elements through the Central American Seaway, before the complete closure of the Isthmus of Panama. This Pliocene origin scenario contrasts with a previously proposed scenario in which Australian GWS colonized the Mediterranean via antipodean northward migration resulting from navigational errors from South Africa during Quaternary climatic oscillations.

The swordfish (Xiphias gladius) is an epi- and mesopelagic oceanic species with a wide geographical range within the tropical and temperate waters of all oceans, and is one of the most important target species in surface-longline fisheries. In order to study the vertical habitat-use and migration patterns of swordfish, and to help delimit the stock boundaries and mixing rate of swordfish between the Mediterranean Sea and the North and South Atlantic, satellite telemetry tagging is used. A total of 26 miniPAT tags have been deployed so far in the North (n = 13) and South Atlantic Oceans (n = 9) and the Mediterranean Sea (n = 4). Of the deployed tags, eight individuals suffered post-release mortality; one was fished after one day; three did not transmit; three tags had premature releases with less than 30 days; four had premature releases with more than 30 days; six tags reached full term; and one individuals’ tag is still at large. The data from ten tags were analyzed for horizontal and vertical habitat use. The results presented herein are preliminary, as more tag deployments are planned. The results show that swordfish moved in several directions, travelling considerable distances in both the North and South Atlantic Ocean, while having shorter displacements in the Mediterranean Sea. Regarding vertical habitat use, swordfish spent most of the day-time in deeper waters, and were closer to the surface during the night-time. The deepest dive recorded was 1480 m. Regarding temperature, swordfish inhabited waters with temperatures ranging from 3.9 ◦C to 30.5 ◦C, mostly residing in waters between 10–12 ◦C during the day-time and in waters >20 ◦C during the night-time. The migration of swordfish in this study agrees with the current stock boundaries defined for this species in the Atlantic Ocean, and shows a high vertical overlap with pelagic longline fisheries that are set during the night-time, SI

The Atlantic bluefin tuna is a highly migratory species emblematic of the challenges associated with shared fisheries management. In an effort to resolve the species' stock dynamics, a genomewide search for spatially informative single nucleotide polymorphisms (SNPs) was undertaken, by way of sequencing reduced representation libraries. An allele frequency approach to SNP discovery was used, combining the data of 555 larvae and young-of-the-year (LYOY) into pools representing major geographical areas and mapping against a newly assembled genomic reference. From a set of 184,895 candidate loci, 384 were selected for validation using 167 LYOY. A highly discriminatory genotyping panel of 95 SNPs was ultimately developed by selecting loci with the most pronounced differences between western Atlantic and Mediterranean Sea LYOY. The panel was evaluated by genotyping a different set of LYOY (n = 326), and from these, 77.8% and 82.1% were correctly assigned to western Atlantic and Mediterranean Sea origins, respectively. The panel revealed temporally persistent differentiation among LYOY from the western Atlantic and Mediterranean Sea (FST = 0.008, p = .034). The composition of six mixed feeding aggregations in the Atlantic Ocean and Mediterranean Sea was characterized using genotypes from medium (n = 184) and large (n = 48) adults, applying population assignment and mixture analyses. The results provide evidence of persistent population structuring across broad geographic areas and extensive mixing in the Atlantic Ocean, particularly in the mid-Atlantic Bight and Gulf of St. Lawrence. The genomic reference and genotyping tools presented here constitute novel resources useful for future research and conservation efforts., This work was carried out under the provision of the ICCAT Atlantic-wide Research Programme for Bluefin Tuna (GBYP), funded by the European Union, by several ICCAT CPCs, the ICCAT Secretariat and other entities (see: http://www.iccat.int/GBYP/en/Budget.htm). Additional funds were provided by the MARES Joint Doctorate Programme Selected Under Erasmus Mundus and coordinated by Ghent University (FPA 2011-0016). Larvae from the Balearic Sea were provided by the ATAME project “Bluefin tuna abundance indices: towards recruitment estimators based on larval ecology” (CTM 2011-29525-C04-02) and the BLUEFIN project “Modelling bluefin spawning areas variability and population dynamics in the Western Mediterranean” (IEO-SOCIB agreement).

Simple Summary Currently procedures used to obtain samples from the gastro-intestinal tract (GIT) and protocols used to perform their respective analyses do not allow a multidisciplinary approach of this system. In fact, the investigations applied on the GIT, when performed singularly, could impair or limit the other analyses, because the currently procedures do not consider the needs of other disciplines. This means that the analyses to perform must be selected a priori, sacrificing the collection of other types of data and leads to the risk of losing important information, especially for wildlife species. To solve this conflict, we implement and standardize a new methodological approach to the GIT of marine mammals, which allow the collection of samples for different disciplines at the same time, performing the respective analyses, interpret and compare their results in a multidisciplinary way. The compatibility of multiple analyses allows the gaining of more information about the cause of death of stranded marine mammals and to enhance the knowledge of their biology and ecology. Abstract Organs and content of the gastro-intestinal tract (GIT) of marine mammals are relevant for a variety of investigations and provide data to researchers from different fields. Currently used protocols applied to the GIT for specific analysis limit the possibility to execute other investigations and important information could be lost. To ensure a proper sample collection and a multidisciplinary investigation of the GIT of marine mammals, a new multi-sieves tool and a specific protocol have been developed. This new device and approach allowed the simultaneous sampling of the GIT and its content for the main investigations concerned. The samples collected during these preliminary trials were suitable to perform all the different research procedures considered in this work. The obtained results show that with a few and easy procedural adjustments, a multidisciplinary sampling and evaluation of the GIT of marine mammals is possible. This will reduce the risk of losing important data aimed at understanding the cause of death of the animal, but also biology and ecology of marine mammals, and other important data for their conservation and habitats management.

Few studies have focused so far on plastic ingestion by sharks in the Mediterranean Sea. The aim of this paper was to determine, for the first time, the plastic litter ingested by blue sharks (Prionace glauca), categorized as "Critically Endangered" in the Mediterranean Sea by IUCN, caught in the Pelagos Sanctuary SPAMI (North-Western Mediterranean Sea). The analysis of the stomach contents was performed following the MSFD Descriptor 10 standard protocol implemented with FT-IR spectroscopy technique. The results showed that 25.26% of sharks ingested plastic debris of wide scale of sizes from microplastics (5 mm) to macroplastics (25 mm). The polyethylene sheetlike user plastics, widely used as packaging material, are the most ingested debris. This research raises a warning alarm on the impact of plastic debris on a threatened species, with a key role in the food web, and adds important information for futures mitigation actions.

20 pages, 9 figures, 5 tables, supplementary data https://doi.org/10.12681/mms.25306, The Mediterranean Sea has a long-lasting history of fishery exploitation that, together with other anthropogenic impacts, has led to declines in several marine organisms. In particular, elasmobranch populations have been severely impacted, with drastic decreases in abundance and species diversity. Based on their experience, fishers can provide information on marine species occurrence, abundance and behavioural traits on a long-term scale, therefore contributing to research on the poorly studied biological aspects of elusive or rare elasmobranch species. In this study, for the first time, the use of the Local Ecological Knowledge (LEK) of fishers was applied to study the behavioural traits of sharks, rays and skates in 12 FAO-GFCM geographical sub-areas (GSAs) of the Mediterranean Sea. This study found both new insight and proved the reliability of LEK-based catch seasonality, reflecting seasonal movements, by comparing LEK-based findings and available literature on five elasmobranch taxa (Mustelus spp., Squalus acanthias, Raja spp., Myliobatis aquila and Scyliorhinus stellaris) in the Adriatic Sea and 7 taxa (Mustelus spp., Raja spp., Prionace glauca, Scyliorhinus canicula, Torpedo spp., Pteroplatytrygon violacea and Isurus oxyrinchus) in the remaining Mediterranean GSAs. In addition, LEK provided new insights into a novel comprehensive representation of species aggregations (Mustelus spp., S. acanthias, M. aquila and S. canicula) in the sampled GSAs and supplied the first descriptions of the size, number of individuals and sex composition of the aggregations. When the limits and shortcomings of LEK-based research are considered, this methodology can be a complementary and cost-effective tool used to study elasmobranchs in either a data-poor scenario or a scenario in which a baseline is missing. LEK can also be useful for the evaluation and inclusion of fishers’ perceptions on bottom-up management and to provide important evidence for conservation plans, This work was supported by funding of Ministero dell’Istruzione, dell’Università e della Ricerca (MIUR) to CM, With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)

Few stock assessments of elasmobranchs have been conducted in the Mediterranean due to the lack of available detailed and precise information. In recent years, in the Mediterranean Sea a major concern on the status of this group does exist and consequently scientists and managers have paid a major attention on the collection of data of fisheries in which they are involved as by-catch, on the impact of different fishing techniques, and on management issues aiming at reducing undesired removals. Information on landings for the more important species is now available in some Mediterranean countries but time series are still too short. Data on age structure of catches is often partial and does not regard all the fisheries in which the species are involved making difficult the reconstruction of the demographic structure of the commercial catches. So far such difficulties made almost impossible the use of age-based analytical models or surplus production models for stock assessment. Recently, stock assessments using simple approaches suitable for data poor stocks were performed for Raja asterias and Raja clavata, Scyliorhinus canicula and Galeus melastomus in the GFCM-GSA9. R. asterias is caught especially by trawlers fleet segments targeting flat fish (15-100 m of depth). R. clavata and S. canicula are in general part of the by-catch of a fishery operating at deeper waters (about 100-200 m) mainly targeting Parapenaeus longirostris, Eledone cirrhosa and Merluccius merluccius. G. melastomus is mainly found in the depth range 200-1200 m and is exclusively caught with bottom trawlers. It constitutes an important by-catch fraction of the Nephrops norvegicus fishery (250-500 m of depth) and the deep-sea shrimps fishery.

Between 2015 and the beginning of 2018 (January-March), 30 cetaceans were found stranded along the Ligurian Sea coast of Italy. Necropsies were performed in 22 cases and infectious diseases resulted the most common cause of death. Three striped dolphins, showed a severe coinfection involving the monophasic variant of Salmonella Typhimurium (Salmonella 1,4,[5],12:i:-). The isolates were characterized based on antimicrobial resistance, Multiple-Locus Variable-number tandem-repeat Analysis (MLVA) and whole-genome sequencing (WGS). All isolates demonstrated the same multidrug resistant genotype (ASSuT isolates), showed three different MLVA profiles, two of which closely related, and were identified as Sequence Type 34. Moreover, Single nucleotide polymorphisms (SNP) analysis confirmed strong correlations between two out of the three isolates. To our knowledge, S. 1,4,[5],12:i:-, one of the most common serovars in cases of human infection and food sources worldwide, has not previously been described in marine mammals, and reports of Salmonella-associated disease in free-ranging cetaceans are rare. These results highlight the role of cetaceans as sentinel species for zoonotic and terrestrial pathogens in the marine environment, suggest a potential risk for cetaceans and public health along the North Western Italian coastline and indicate cetaceans as a novel potential reservoir for one of the most widespread Salmonella serovars.

Listeria monocytogenes, Toxoplasma gondii and Brucella spp. can infect a wide range of species, including humans. In cetaceans, meningoencephalitis has been associated with T. gondii and Brucella spp. infection, whereas to our knowledge, L. monocytogenes infection has not previously been reported. Meningoencephalitis and L. monocytogenes, T. gondii and Brucella spp. were identified by means of both direct and indirect laboratory techniques in an adult female striped dolphin Stenella coeruleoalba found stranded in January 2015 on the Ligurian Sea coast, northwestern Italy. The animal was emaciated, and histopathology disclosed severe meningoencephalitis. The nature of the inflammatory response and intra-lesional protozoa were consistent with a mixed infection by L. monocytogenes, T. gondii and Brucella spp. We believe this is an unprecedented case of infection by 3 zoonotic pathogens and also the first bacteriologically confirmed case report of neurolisteriosis in cetaceans. Cerebral toxoplasmosis and neurobrucellosis may have led to the animal's disorientation and stranding, with L. monocytogenes having likely exacerbated the coinfection leading to the demise of this dolphin.

Mass strandings of sperm whales (Physeter macrocephalus) are rare in the Mediterranean Sea. Nevertheless, in 2014 a pod of 7 specimens stranded alive along the Italian coast of the Central Adriatic Sea: 3 individuals died on the beach after a few hours due to internal damages induced by prolonged recumbency; the remaining 4 whales were refloated after great efforts. All the dead animals were genetically related females; one was pregnant. All the animals were infected by dolphin morbillivirus (DMV) and the pregnant whale was also affected by a severe nephropathy due to a large kidney stone. Other analyses ruled out other possible relevant factors related to weather conditions or human activities. The results of multidisciplinary post-mortem analyses revealed that the 7 sperm whales entered the Adriatic Sea encountering adverse weather conditions and then kept heading northward following the pregnant but sick leader of the pod, thereby reaching the stranding site. DMV infection most likely played a crucial role in impairing the health condition and orientation abilities of the whales. They did not steer back towards deeper waters, but eventually stranded along the Central Adriatic Sea coastline, a real trap for sperm whales.

Tattoo skin disease (TSD) is a poxviral disease typical of cetaceans. Two juvenile and well-preserved male striped dolphins (Stenella coeruleoalba), found stranded along the Tuscany and Latium coasts of Italy in 2015 and 2016, respectively, showed typical skin lesions ascribable to TSD. Histological, ultrastructural and biomolecular investigations confirmed a poxviral aetiology for the aforementioned skin lesions. To our knowledge, this should be the first report of TSD in cetaceans stranded along the Italian coastline. As organochlorines like PCBs and DDTs are known to be highly immunotoxic, the tissue loads of these contaminants were evaluated, in order to increase our knowledge on their potential role as well as on the relationships between the level of exposure to these pollutants and poxviral infection's occurrence.

A juvenile female striped dolphin Stenella coeruleoalba live stranded on 4 March 2016 at Alassio, western Ligurian Sea coast, Italy. The dolphin died shortly after stranding, and a complete postmortem examination was performed. Necropsy revealed severe tracheal occlusion and unilateral bronchial stenosis with luminal accumulation of abundant green-yellow mucous-gelatinous material. Histological features suggestive of tracheobronchial aspergillosis were observed. Cultures of lung tissue and tracheo-bronchial exudate isolated Aspergillus fumigatus, identified by a Microseq D2 LSUrDNA fungal sequencing kit. A pan-Herpesvirus nested-PCR assay on frozen samples obtained from multiple organs was positive. Phylogenetic analysis on the partial DNA polymerase gene revealed that the striped dolphin isolate was closely related to known cetacean Alphaherpesvirus sequences from the same host species. Attempted virus isolation was unsuccessful. The tissue levels of different persistent organic pollutants and the toxicological stress, evaluated using a theoretical model, showed a severely impaired immune response. This study reports the first case of occlusive mycotic tracheobronchitis in a free-living cetacean and the first molecular identification of an Alphaherpesvirus in a free-ranging striped dolphin stranded on the coast of Italy.

The blackfish Centrolophus niger (Perciformes: Centrolophidae) is a mesopelagic fish living offshore in depth range from 40 to 1000 m. Juveniles occur in surface waters while adults live deeper. Feeding of blackfish is not selective, including mainly small fish, squids and large pelagic crustaceans. Among the parasitofauna reported in blackfish, tapeworms of the order Bothriocephalidea are considered very common. One of them, Echinophallus wageneri (Cestoda: Echinophallidae) is a large worm, up to 50 cm long and 2 cm wide, with a flat strobila folded along longitudinal axis (convex dorsally and concave ventrally). The aim of this study is to define the prevalence of E. wageneri in a C. niger population of the Ligurian Sea. From March to April 2015, 42 specimens of blackfish were caught by local fisherman from the sea off the coast of Imperia (Italy). The visceral package of each blackfish was tied at its ends and placed in bags whit an identification code. In the laboratory, the samples were examined fresh or after freezing at -20°C. Parasites were fixed in ethanol (70%) and subjected to identification on the basis of morphological characters. The presence of E. wageneri was detected in all the samples examined with an intensity of infection ranging between 2 and 48 (MI=16,6). Several other species of not yet identified cestodes were found in coinfection with E. wageneri. These results provide preliminary data about the prevalence of E. wageneri in the blackfish, species with an increasing interest in local fish market.

On 9th September 2015 the head of a shark belonging to the genus Alopias, was landed at Camogli harbour in the Ligurian Sea (North Western Mediterranean). The specimen has been caught 16 miles far from the coast (44° 06’ N, 008° 57’ E) as by-catch of the mesopelagic swordfish longline, but only the head was recovered, due to the predatory/scavenging activity by other shark specimens. The specimen was a female of big-eye thresher shark Alopias superciliosus a highly migratory species worldwide distributed in tropical and temperate waters but rarely caught in the Mediterranean Sea. The present record is the northenmost reported for this species in the Mediterranean area and the sixth in Italian waters.

Nine striped dolphins Stenella coeruleoalba and 1 bottlenose dolphin Tursiops truncatus stranded along the Ligurian Sea coast of Italy were necropsied between February 2011 and April 2012. Macroscopic and histological findings were observed in the hearts of all animals and included saccular aneurysms of the pulmonary trunk (n = 3), cirsoid aneurysms (n = 1), right ventricular dilation (n = 1) associated with hypoplasia of the tricuspid chordae (n = 1), valvular fibrosis (n = 3), mitral leaflet thickening (n = 1), left ventricular hypertrophy (n = 1), lymphocytic myocarditis (n =1), and Lambl's excrescences (n = 4). To our best knowledge Lambl's excrescences, aneurysm of the pulmonary trunk, and cirsoid aneurysms have not previously been described in marine mammals, and some of these findings should be taken into account as possible causes of dolphin morbidity, mortality, and stranding.

The stomach contents of a male sperm whale,Physeter macrocephalus, stranded on Forte dei Marmi beach (Italy, Ligurian Sea) were examined. Food items consisted exclusively of cephalopod hard parts: 233 upper and 291 lower beaks and one fish eye lens. The majority of the identified cephalopod beaks belonged toHistioteuthis bonnellii, but a few beaks ofGaliteuthis armataandOctopoteuthissp. were also found. A new beak size–cephalopod size regression was created forH. bonnelliiwith specimens caught in the study area. Reconstructed prey weight for the species was much higher when applying this new regression instead of Clarke's, highlighting the need for area- and species-specific regressions for dietary studies. Our analysis represents the second report on the stomach contents of sperm whales from the Mediterranean and the first available information for the Western basin.

WOS: 000382753200012, The genus Octopoteuthis includes squids inhabiting meso-and bathypelagic waters worldwide. Of the seven presently named species distributed in the world's oceans, only Octopoteuthis sicula has been reported for certain in the Mediterranean Sea to date. However, mixed and confusing descriptions of the systematic characters useful for identifying the species occur in the literature. Similarly, molecular analysis results available for the genus are contradictory and inconsistent. The research herein was undertaken firstly to clarify the systematic status of the genus in the Mediterranean Sea and confirm the presence of a single species, namely O. sicula. Additional goals were the assessment of the validity of systematic characters to identify the species and the analysis of beak morphology to provide useful tools in prey-predator relationship studies. Octopoteuthis specimens from various areas of the Mediterranean Sea and the Atlantic and Pacific oceans were compared, and the analysis of traditional morphological characters was combined with molecular genetics and the study of beaks. Molecular genetics and beak morphology results support the existence of a single species in the Mediterranean Sea. Additional evidence would suggest that this species is also distributed in the north-eastern Atlantic. The morphological characters reported in the literature to identify O. sicula did not identify Mediterranean specimens, with the exception of the two tail photophores. All information collected supports the need for a reconsideration of morphological characters used to identify Octopoteuthis species., David and Lucile Packard FoundationThe David & Lucile Packard Foundation, We heartily thank Jonathan Ablett for his kind assistance in loaning the holotype of Octopoteuthis sicula and providing photographs and related information. We also want to thank the David and Lucile Packard Foundation for the support given to part of the research at the base of this work. Angel Guerra provided positive criticism and constructive suggestions which greatly improved the quality of this document, for which we are deeply grateful. We also wish to thank our friend and colleague Louise Allcock for her critical reading of the manuscript and helpful suggestions. Last but not least, we feel grateful to the reviewers for their suggestions and their much appreciated supportive attitude and useful comments.

This article presents a review and summary of the data on large pelagic fish, collected over the period 1990–2007, thanks to national and European Community research programmes. Swordfish are present in the Ligurian Sea at all life history stages. Time series of longline fishing catch per unit effort (CPUE) values show a good exploitation status, possibly related to the dismission of past questionable fishing technics (e.g. ‘spadare’ nets). CPUE values were also negatively related to North Atlantic oscillation: climatic factors probably had synergic effects. Bluefin is present in the Ligurian Sea with mainly schools of young fish aged 1–4 years, which feed on small pelagic fish and on the Ligurian krill Meganyctiphanes norvegica. Recent limitations on catches have severely reduced local fishing activities. Following the dismission of purse seiners, artisanal hook-based fisheries should be maintained, regardless of the length of fish caught, as a way of monitoring stock status. The two most abundant specie...

Between 2007 and 2014, 83 cetaceans were found stranded along the Ligurian coast of Italy, in the Pelagos Sanctuary, the largest marine protected area in the Mediterranean basin. Forty-nine (59%) were submitted to complete or partial necropsy, depending on the conservation status of the carcass. Based on gross and histological pathology and ancillary testing, the cause of death was determined and categorized as anthropogenic or natural (i.e., nonanthropogenic) in origin for 33 animals (67%) and of undetermined origin in the remaining 16 (33%). Natural causes of death, accompanied by either poor or good nutritional status, were attributed to 29 animals (59%), whereas four (8%) were diagnosed with an anthropogenic cause of death, consisting of interaction with fishing activities. Infectious and noninfectious disease was the most common cause of death, involving 29 cetaceans (59%). These data are valuable for understanding health and mortality trends in cetacean populations and can provide information for establishing policies for cetacean conservation and management in such an important protected area of the Mediterranean basin.

A new species of trichosomoidid nematode, Huffmanela paronai sp. n., is established on the basis of its egg morphology and biological characters. The dark-shelled, embryonated eggs of this histozoic parasite occur in masses in the epidermis of the swordfish Xiphias gladius L. (Xiphiidae, Perciformes) from the Ligurian Sea in northern Italy. The eggs are concentrated in groups appearing as black spots in the skin of the fish host, being distributed mainly on the lower part of its body (lower jaw, gill covers, pectoral, anal and caudal fins, lower half of body). The parasite's eggs are characterised mainly by their shape and markedly small size (48-51 x 21-24 microm), an aspinose surface, relatively small polar plugs, and thick egg wall (3 microm). This is the first Huffmanela species reported from fish in Europe.

Two stocks of bluefin tuna (Thunnus thynnus) inhabit the north Atlantic; the western and eastern stocks spawn in the Gulf of Mexico and the Mediterranean Sea respectively. Trans-Atlantic movements occur outside spawning time whereas natal homing maintains stock structure. Commercial fisheries may exploit a mixed assemblage of both stocks. The incorporation of mixing rates into stock assessment is precluded by uncertainties surrounding stock discrimination. Otolith shape descriptors were used to characterise western and eastern stocks of Atlantic bluefin tuna in the present study and to estimate stock composition in catches of unknown origin. Otolith shape varied with length and between locations and years. Within a restricted size range (200–297-cm fork length (FL)) the two stocks were distinguished with an accuracy of 83%. Bayesian stock mixture analysis indicated that samples from the east Atlantic and Mediterranean were predominantly of eastern origin. The proportion assigned to the eastern stock showed slight spatial variation; however, overlapping 95% credible intervals indicated no significant difference (200–297cm FL: central Atlantic, 73–100%; Straits of Gibraltar, 73–100%; Morocco, 50–99%; Portugal 64–100%). Otolith shape could be used in combination with other population markers to improve the accuracy of mixing rate estimates for Atlantic bluefin tuna.

Examination of 3 specimens of the Mediterranean flyingfish Cheilopogon heterurus (Rafinesque) from the Ligurian Sea, Italy, revealed the presence of numerous, dark-shelled trichinelloid eggs (69 to 75 x 30 to 33 microm) inside the innermost layer of the swimbladder, mostly located in clumps arranged in a distinct pattern. These were identified as Huffmanela schouteni Moravec et Campbell, 1991, a species known so far as eggs in flyingfishes and in the stools of humans in Curaçao. This is the first finding of this parasite in Europe and C. heterurus represents a new host record.

BackgroundMass strandings of sperm whales (Physeter macrocephalus) remain peculiar and rather unexplained events, which rarely occur in the Mediterranean Sea. Solar cycles and related changes in the geomagnetic field, variations in water temperature and weather conditions, coast geographical features and human activities have been proposed as possible causes. In December 2009, a pod of seven male sperm whales stranded along the Adriatic coast of Southern Italy. This is the sixth instance from 1555 in this basin.Methodology/principal findingsComplete necropsies were performed on three whales whose bodies were in good condition, carrying out on sampled tissues histopathology, virology, bacteriology, parasitology, and screening of veins looking for gas emboli. Furthermore, samples for age determination, genetic studies, gastric content evaluation, stable isotopes and toxicology were taken from all the seven specimens. The animals were part of the same group and determined by genetic and photo-identification to be part of the Mediterranean population. Causes of death did not include biological agents, or the "gas and fat embolic syndrome", associated with direct sonar exposure. Environmental pollutant tissue concentrations were relatively high, in particular organochlorinated xenobiotics. Gastric content and morphologic tissue examinations showed a prolonged starvation, which likely caused, at its turn, the mobilization of lipophilic contaminants from the adipose tissue. Chemical compounds subsequently entered the blood circulation and may have impaired immune and nervous functions.Conclusions/significanceA multi-factorial cause underlying this sperm whales' mass stranding is proposed herein based upon the results of postmortem investigations as well as of the detailed analyses of the geographical and historical background. The seven sperm whales took the same "wrong way" into the Adriatic Sea, a potentially dangerous trap for Mediterranean sperm whales. Seismic surveys should be also regarded as potential co-factors, even if no evidence of direct impact has been detected.

This article reports the results of necropsy, parasitologic, microbiologic, histopathologic, immunohistochemical, indirect immunofluorescence, biomolecular, and serologic investigations on 8 striped dolphins ( Stenella coeruleoalba) found stranded from August to December 2007 on the Ligurian Sea coast of Italy. Severe, nonsuppurative meningoencephalitis was found in 4 animals, as characterized by prominent perivascular mononuclear cell cuffing and macrophage accumulations in neuropil. These lesions were associated with mild lymphocytic–plasmacytic infiltration of choroid plexuses in 1 dolphin. Toxoplasma gondii cysts and zoites, confirmed by immunohistochemical labeling, were scattered throughout the brain parenchyma of 2 of the 4 dolphins. No viral inclusions were seen in the brain of any animal. Other findings included severe bronchointerstitial pneumonia and pulmonary atelectasis, consolidation, and emphysema. Parasites were identified in a variety of organs, including lung ( Halocerchus lagenorhynchi). Microbiologic and serologic examinations for Brucella spp were negative on all 8 dolphins. The 4 animals with meningoencephalitis had serum antibodies against T gondii (titers ranging from 1:80 to 1:320) but not against morbillivirus. In contrast, the other 4 dolphins were seropositive for morbillivirus (with titers ranging from 1:10 to 1:40) but seronegative for T gondii. No morbillivirus antigen or nucleic acid was detected in the tissues of any dolphin. It is concluded that the severe lung and brain lesions were the cause of death and that T gondii was the likely etiologic agent of the cerebral lesions. Morbillivirus infection was not considered to have contributed to death of these animals.

The record of one adult female of the bluespotted cornetfish Fistularia commersonii Ruppell, 1838, caught using trawl nets in coastal waters near Sanremo, Western Ligurian Sea, in October 2007 is reported. This record confirms the rapid spread of the species and suggests a possible fast expansion toward French and Spanish waters by means of the Western Mediterranean Northern Current. Previous records in Italian waters apparently indicate a pioneer phase of colonization by adult fish and a stabilized phase, with adult and young fish, four years later.