Anisakid nematode larvae in the liver of Atlantic cod Gadus morhua L. from West Greenland.

Anisakid nematode larvae occur frequently in the liver of Atlantic cod, but merely few infection data from cod in waters around Greenland exist. The present study reports the occurrence of third-stage anisakid larvae in the livers of 200 Atlantic cod caught on fishing grounds along the West coast of Greenland (fjord systems of Maniitsoq) in May, June, August and September 2017. Classical and molecular helminthological techniques were used to identify the nematodes. A total of 200 cod livers were examined, and 194 were infected with third-stage nematode larvae (overall prevalence of infection 97%) with a mean intensity of 10.3 (range between 1 and 44 parasites per fish). Prevalences recorded were 96% for Anisakis simplex (s.l.), 55% for Pseudoterranova decipiens (s.l.) and 8% for Contracaecum osculatum (s.l.). Sequencing the mtDNA cox2 from 8 out of 23 these latter larvae conferred these to C. osculatum sp. B. A clear seasonal variation was observed, with a rise in A. simplex (s.l.) and P. decipiens (s.l.) occurrence in June and August and a decline in September. The study may serve as a baseline for future investigations using the three anisakids as biological indicators in Greenland waters.

Mitigating the Twin Threats of Climate-Driven Atlantic Hurricanes and COVID-19 Transmission.

The co-occurrence of the 2020 Atlantic hurricane season and the ongoing coronavirus disease 2019 (COVID-19) pandemic creates complex dilemmas for protecting populations from these intersecting threats. Climate change is likely contributing to stronger, wetter, slower-moving, and more dangerous hurricanes. Climate-driven hazards underscore the imperative for timely warning, evacuation, and sheltering of storm-threatened populations - proven life-saving protective measures that gather evacuees together inside durable, enclosed spaces when a hurricane approaches. Meanwhile, the rapid acquisition of scientific knowledge regarding how COVID-19 spreads has guided mass anti-contagion strategies, including lockdowns, sheltering at home, physical distancing, donning personal protective equipment, conscientious handwashing, and hygiene practices. These life-saving strategies, credited with preventing millions of COVID-19 cases, separate and move people apart. Enforcement coupled with fear of contracting COVID-19 have motivated high levels of adherence to these stringent regulations. How will populations react when warned to shelter from an oncoming Atlantic hurricane while COVID-19 is actively circulating in the community? Emergency managers, health care providers, and public health preparedness professionals must create viable solutions to confront these potential scenarios: elevated rates of hurricane-related injury and mortality among persons who refuse to evacuate due to fear of COVID-19, and the resurgence of COVID-19 cases among hurricane evacuees who shelter together.

Ascaridoids in commercial fish: Occurrence, intensity and localization in whole fish and fillets destined for the Belgian market.

Anisakidae and Raphidascaridae are marine nematodes present in a wide range of fish hosts, which may cause gastro-intestinal complaints and/or allergy in human, in addition to economic losses for the industry. Data regarding the presence of these parasites in fish for the Belgian market is currently missing; therefore, our aim was to investigate the presence and intensity of ascaridoids in a wide range of commercially fish species. A total of 415 fish samples, belonging to 36 different fish species, were collected from a Belgian whole-sale company. Ascaridoid larvae from the viscera (if present) and the muscles were collected by enzymatic digestion and the prevalence, median intensity, mean number of larvae per 100 g infected muscle, and localisation were determined. An overall prevalence of 53% [95%-CI: 42-63%] in the viscera and 27% [95%-CI: 23-32%] in the muscles was observed. Infection in the muscles varied between the fish species; no larvae were detected in 13 fish species, while a high prevalence (>78%) was observed in pollack, halibut, and gurnard. Most samples originated from the Northeast Atlantic Ocean, with the highest prevalence in the muscles observed in the Barents & Norwegian Sea (65% [95%-CI: 38-86]). Muscle samples were, if possible, divided in an anterior region, belly flap, medial region, and posterior region, with the most infections and larvae found in the belly flaps. In all samples, a total of 2569 larvae were recovered, with 1594 larvae originating from the viscera and 975 from the muscles; with an average of two larvae per 100 g infected fillet detected. Larvae were morphologically identified, and a subgroup was further confirmed using PCR/RFLP, resulting ultimately in the identification of Anisakis simplex s.s. (1853 larvae), A. pegreffii (137), A. simplex/pegreffii hybrid genotype (38), Pseudoterranova decipiens (160) and Hysterothylacium aduncum (380). This study demonstrates that ascaridoid larvae are highly prevalent in different fish species on the Belgian market.

Recent increase of ulcerative lesions caused by Anisakis spp. in cetaceans from the north-east Atlantic.

Species of Anisakis typically infect the stomach of cetaceans worldwide, often causing ulcerative lesions that may compromise the host's health. These nematodes also cause anisakiasis or allergic reactions in humans. To assess the risks of this emerging zoonosis, data on long-term changes in Anisakis infections in cetaceans are necessary. Here, we compare the prevalence and severity of ulcerative lesions caused by Anisakis spp. in five cetacean species stranded along the north-west Spanish coast in 2017-2018 with published data from 1991-1996. Open ulcers were found in 32/43 short-beaked common dolphins, Delphinus delphis; 3/5 striped dolphins, Stenella coeruleoalba; 1/7 bottlenose dolphins, Tursiops truncatus; and 1/3 harbour porpoises, Phocoena phocoena meridionalis; a single individual of long-finned pilot whale, Globicephala melas, was found uninfected. In common dolphins, the mean abundance of open ulcers per host was 1.1 (95% confidence interval: 0.8-1.3), with a maximum diameter (mean ± standard deviation) of 25.4 ± 16.9 mm. Stomachs with scars or extensive fibrosis putatively associated with Anisakis were detected in 14 and five animals, respectively. A molecular analysis based on the mitochondrial cytochrome c oxidase II gene using 18 worms from three cetacean species revealed single or mixed infections of Anisakis simplex sensu stricto and Anisakis pegreffii. Compared with the period 1991-1996, we found a strong increase of prevalence, abundance and extension of ulcerative lesions in most cetacean species. Anisakis populations could have increased in the study area over the last decades, although we cannot rule out that a higher environmental stress has also boosted the pathological effects of these parasites.

Prevalence, intensity and pathology of the nasal parasite Nasicola hogansi in Atlantic bluefin tuna (Thunnus thynnus).

Ectoparasitic flatworms of Nasicola (Monogenoidea: Capsalidae), which infect nasal epithelium of true tunas (Thunnus spp.), are not well studied, nor have their impacts on the host's olfactory organ been evaluated. Infections of Nasicola hogansi on Atlantic bluefin tuna, Thunnus thynnus, were investigated with emphasis on the relationship between infection prevalence, abundance and mean intensity with bluefin tuna size, sex, body condition and capture month, as well as histopathological effects. Commercially caught Atlantic bluefin tuna (n = 161, 185-305 cm curved fork length) from the Gulf of Maine were sampled during June through August 2009 for infections by N. hogansi. A total of 247 specimens of N. hogansi were collected, with a prevalence of 45.3%, mean abundance of 1.57 (CI: 1.21-2.03) and mean intensity of 3.45 (CI: 2.91-4.22). Neither fish sex nor landing month had a significant effect on parasite parameters. Larger and better-conditioned Atlantic bluefin tuna had a higher mean intensity of infection. Pathology associated with infection by N. hogansi included extensive necrosis, sloughing of the nasal epithelium and associated inflammation of underlying connective tissues. Further epidemiological and pathological study of this host-parasite system is warranted since impaired olfaction, if present, could adversely affect spawning and migration of this top ocean predator.

Presence and genetic variability of Piscine orthoreovirus genotype 1 (PRV-1) in wild salmonids in Northern Europe and North Atlantic Ocean.

Piscine orthoreovirus genotype 1 (PRV-1) is widespread in farmed Atlantic salmon (Salmo salar L.) populations in northern Europe, Canada and Chile. PRV-1 occurs in wild fish in Norway and Canada; however, little information of its geographical distribution in wild populations is currently available, and the effect of PRV-1 infection in wild populations is currently unknown. In this study, we present the findings of a survey conducted on 1,130 wild salmonids sampled in Denmark, Sweden, Ireland, Faroe Islands, France, Belgium and Greenland between 2008 and 2017. PRV-1 is reported for the first time in wild salmonids in Denmark, Sweden, Faroe Island and Ireland. The annual PRV-1 prevalence ranged from 0% in France, Belgium and Greenland to 43% in Faroe Islands. In total, 66 samples tested positive for PRV-1, including Atlantic salmon broodfish returning to spawn and Atlantic salmon collected at the feeding ground north of Faroe Islands. The phylogenetic analysis of S1 sequences of the PRV-1 isolates obtained in this survey did not show systematic geographical distribution. This study sheds light on the spread and genetic diversity of the virus identified in populations of free-living fish and provides rationale for screening wild broodfish used in restocking programmes.

Occurrence of larval ascaridoid nematodes in the Argentinean short-finned squid Illex argentinus from the Southwest Atlantic Ocean (off Falkland Islands).

The Argentinean short-finned squid (Illex argentinus) is an oceanic, neritic species widely distributed off the east coast of South America, representing the most abundant commercially exploited squid species in these waters. Despite the great commercial importance of Argentinean short-finned squid as a food resource, and as frozen product exported to Europe, the presence of zoonotic anisakid nematodes, especially in the mantle of the squid, is poorly known. The occurrence and site of infection of larval ascaridoid nematodes in 70 I. argentinus caught off the Falkland Islands were investigated. Squids were examined using the UV-Press method. In total, 30 nematodes were detected in the viscera and mantle. According to morphology, 27 were third-stage larvae (L3) belonging to genus Anisakis, while three were L3 assigned to Hysterothylacium. Anisakis pegreffii (n = 27) were identified by sequence analysis of the mtDNA cox2 and the partial EF1 α-1 region of nDNA genes; Hysterothylacium aduncum (N = 3) were identified by sequence analysis of the ITS rDNA region. These findings represent the first molecular identification of A. pegreffii and H. aduncum in I. argentinus. Both prevalence (P = 15.7%) and abundance (A = 0.39) of infection with A. pegreffii were low, and even lower values of infection were recorded for H. aduncum (P = 2.1%, A = 0.04). Only 3 out of 70 (4.3%) squids hosted A. pegreffii larvae in the mantle. Larvae infecting viscera were coiled and mainly attached to outer surface of visceral organs. Mantle-infecting larvae were situated in the posterior half. Thus, these results suggest that - although low - the risk of acquiring anisakiasis from consumption of raw, marinated and/or undercooked short-finned squid products still exists.

Parasites of amberjacks from the archipelago of Madeira, Eastern Atlantic.

Amberjacks, Seriola spp., are a group of carangid fishes of economic importance for fisheries and aquaculture worldwide. A survey of the parasites of greater amberjack S. dumerili and almaco jack or longfin yellowtail S. rivoliana from the Madeira archipelago (including the Madeira and Selvagens Islands) was carried out. This work is the first parasitological study of these 2 species in the Eastern Atlantic. A total of 14 parasite taxa were detected in the 47 fish analysed: Allencotyla mcintoshi, Stephanostomum petimba, Rhadinorhynchus sp. and Caligus aesopus (in both Seriola spp.); Dionchus agassizi, Zeuxapta seriolae, Tormopsolus orientalis, Didymocystis sp. and Anisakis sp. (in S. rivoliana); Tetrochetus coryphaenae, Stephanostomum sp., S. ditrematis, Oncophora melanocephala and Hysterothylacium seriolae (in Seriola dumerili). The monogenean Dionchus agassizi and the nematode O. melanocephala constitute new host records for the genus Seriola, and the species Allencotyla mcintoshi, Z. seriolae, Tormopsolus orientalis, H. seriolae, and C. aesopus are reported in the region of Madeira for the first time. Some of the parasites detected, in particular Z. seriolae and C. aesopus, could constitute a threat to amberjack aquaculture, and measures should be taken to prevent their introduction into sea cages.

Influence of confluent marine currents in an ecotonal region of the South-West Atlantic on the distribution of larval anisakids (Nematoda: Anisakidae).

BACKGROUND: In the marine environment, transitional zones between major water masses harbour high biodiversity, mostly due to their productivity and by containing representatives of species characteristic of adjacent communities. With the aim of assessing the value of larval Anisakis as zoogeographical indicators in a transitional zone between subtropical and sub-Antarctic marine currents, larvae obtained from Zenopsis conchifer were genetically identified. Larvae from Pagrus pagrus and Merluccius hubbsi from two adjacent zoogeographical provinces were also sequenced. RESULTS: Four species were genetically identified in the whole sample, including Anisakis typica, A. pegreffii, A. berlandi and a probably new species related to A. paggiae. Anisakis typica and A. pegreffii were identified as indicators of tropical/subtropical and sub-Antarctic waters, respectively, and their presence evidenced the transitional conditions of the region. Multivariate analyses on prevalence and mean abundance of Anisakis spp. of 18 samples represented by 9 fish species caught south of 35°S determined that host trophic level and locality of capture were the main drivers of the distribution of parasites across zoogeographical units in the South-West Atlantic. CONCLUSIONS: Most samples followed a clear zoogeographical pattern, but the sample of Z. conchifer, composed mostly of A. typica, was an exception. This finding suggests that population parameters of A. typica and A. pegreffii could differ enough to be considered as a surrogates of the identity of larvae parasitizing a given host population and, therefore, a step forward the validation of the use of larval Anisakis as biological indicators for studies on host zoogeography.

Dinoflagellates Amyloodinium and Ichthyodinium (Dinophyceae), parasites of marine fishes in the South Atlantic Ocean.

The morphology and molecular phylogeny of the parasitic dinoflagellates Ichthyodinium chabelardi and Amyloodinium ocellatum was investigated off Brazil (South Atlantic Ocean). This is the first record of Ichthyodinium and the first molecular data of both parasites from the southern hemisphere. I. chabelardi infected the yolk of eggs of wild populations of Argentine anchovy Engraulis anchoita (Engraulidae) and Brazilian sardinella Sardinella brasiliensis (Clupeidae) in different seasons. The small subunit (SSU) rRNA and internal transcribed spacer (ITS) gene sequences were identical and confirmed Ichthyodinium as a host generalist. The new sequences clustered with the type species I. chabelardi from the North Atlantic and environmental sequences from the Pacific Ocean. A second species from the western Pacific remains undescribed. A. ocellatum was isolated from the gills of a cultured cobia Rachycentron canadum after causing mortality. The SSU rRNA gene sequence of the Brazilian isolate was almost identical to those from the northern hemisphere. This suggests a single species with a widespread distribution, although it is uncertain whether the species has a natural pantropical distribution or is the result of artificial distribution due to human-induced fish transport.

Pulmonary and systemic fungal infections in an Atlantic spotted dolphin and a Bryde's whale, Brazil.

We report the gross and microscopic findings and molecular identification of 2 cases of hyphate fungal infection in cetaceans from Brazil. The first case involved an adult male Atlantic spotted dolphin Stenella frontalis with localized pulmonary disease characterized by pyogranulomatous and necrotizing bronchopneumonia with intralesional hyphae. The second case involved an adult male Bryde's whale Balaenoptera edeni with orchitis, periorchitis, mesenteric lymphadenitis and pyogranulomatous bronchopneumonia with intralesional hyphae. PCR analysis from the dolphin's lung yielded Aspergillus fumigatus, and the fungus from the whale's mesenteric lymph node showed the greatest identity to Nanniziopsis obscura and Stagonosporopsis cucurbitacearum These cases represent the first reports of pulmonary aspergillosis by A. fumigatus in an Atlantic spotted dolphin and systemic mycosis by a possibly novel Onygenales in marine mammals.

Distribution of anisakid nematodes parasitizing rajiform skates under commercial exploitation in the Southwestern Atlantic.

In order to evaluate the infestation by anisakids present in elasmobranchs and their distribution in the Argentine Sea, this study was carried at a regional scale with the following aims: 1) to identify those anisakid species present in skates under exploitation; 2) to characterize quantitatively these infestations and 3) to determine those factors driving the variability in parasite burdens across skate species. A total of 351 skates, belonging to 3 species (218 Sympterygia bonapartii, 86 Zearaja chilensis and 47 Atlantoraja castelnaui) and from different localities of the Argentine Sea were examined for anisakids. Parasites were found in the stomach wall at high prevalence in some samples. Based on morphology and mtDNA cox2 sequences analyses (from 24 larval worms), specimens were identified as Anisakis berlandi, A. pegreffii and Pseudoterranova cattani; the last two known as potentially pathogenic for humans. Differential distribution patterns were observed across parasite and hosts species. In general, fish caught in southern and deeper waters exhibited higher loads of Anisakis spp., whereas infestation levels by P. cattani increase in larger skates. Taking into account that the mere presence of worms or their antigens in fish meat can provoke allergic responses, information on distribution of parasites and their variability is essential for the implementation of food safety practices.

Intestinal helminth fauna of the shortfin mako Isurus oxyrinchus (Elasmobranchii: Lamnidae) in the northeast Atlantic Ocean.

Large oceanic sharks represent a suitable model to investigate the influence of a host's oceanic conditions on the structure of its helminth communities. In this study, we describe the intestinal helminth fauna, and investigate determinants of infracommunity structure, in 39 specimens of shortfin mako Isurus oxyrinchus collected in the NE Atlantic. Six cestode species were found in the spiral valve of makos: 3 are typical from lamnid sharks, namely, gravid specimens of Clistobothrium montaukensis, Gymnorhynchus isuri and Ceratobothrium xanthocephalum, and 3 are immature specimens of cestode species common to several elasmobranchs, namely, Dinobothrium septaria, Nybelinia lingualis, and Phyllobothrium cf. lactuca. In addition, L3 larvae of Anisakis sp. type I were detected. Infracommunities were species poor and had low total helminth abundance. The result of Schluter's variance ratio test was compatible with the hypothesis of independent colonization of helminth taxa. These results conform to previous studies on oceanic predators that have hypothesized that these hosts should have depauperate and unpredictable helminth infracommunities because oceanic conditions hamper parasite transmission. However, mean species richness and mean total abundance of cestodes of shortfin mako and other oceanic sharks did not significantly differ from those of elasmobranchs from other habitats. This suggests that the large body size and prey consumption rates of oceanic sharks offset the negative 'dilution' effect of oceanic habitat on transmission rates. Additionally, or alternatively, parasites of oceanic sharks may have expanded the use of intermediate hosts through the trophic web to spread out the risk of failure to complete their life cycles.

Toxoplasma gondii in stranded marine mammals from the North Sea and Eastern Atlantic Ocean: Findings and diagnostic difficulties.

The occurrence of the zoonotic protozoan parasite Toxoplasma gondii in marine mammals remains a poorly understood phenomenon. In this study, samples from 589 marine mammal species and 34 European otters (Lutra lutra), stranded on the coasts of Scotland, Belgium, France, The Netherlands and Germany, were tested for the presence of T. gondii. Brain samples were analysed by polymerase chain reaction (PCR) for detection of parasite DNA. Blood and muscle fluid samples were tested for specific antibodies using a modified agglutination test (MAT), a commercial multi-species enzyme-linked immunosorbent assay (ELISA) and an immunofluorescence assay (IFA). Out of 193 animals tested by PCR, only two harbour porpoise (Phocoena phocoena) cerebrum samples, obtained from animals stranded on the Dutch coast, tested positive. The serological results showed a wide variation depending on the test used. Using a cut-off value of 1/40 dilution in MAT, 141 out of 292 animals (41%) were positive. Using IFA, 30 out of 244 tested samples (12%) were positive at a 1/50 dilution. The commercial ELISA yielded 7% positives with a cut-off of the sample-to-positive (S/P) ratio≥50; and 12% when the cut-off was set at S/P ratio≥20. The high number of positives in MAT may be an overestimation due to the high degree of haemolysis of the samples and/or the presence of lipids. The ELISA results could be an underestimation due to the use of a multispecies conjugate. Our results confirm the presence of T. gondii in marine mammals in The Netherlands and show exposure to the parasite in both the North Sea and the Eastern Atlantic Ocean. We also highlight the limitations of the tests used to diagnose T. gondii in stranded marine mammals.

Ecotonal marine regions - ecotonal parasite communities: helminth assemblages in the convergence of masses of water in the southwestern Atlantic Ocean.

With the aim of evaluating the utility of marine parasites as indicators of ecotonal regions in the marine environment, we analysed data on assemblages of long-lived larval parasites of Zenopsis conchifer inhabiting the region of convergence of three masses of water in the southwestern Atlantic Oceans. These masses of water with different origins are expected to affect the structure of parasite communities by acting as sources of infective stages of helminth species typical of adjacent zoogeographical regions. Multivariate analyses at both infracommunity and component community levels, including data of four other species recognised as harbouring parasite assemblages representatives of these zoogeographical regions, were carried out to corroborate the existence of repeatable distribution patterns and to provide further evidence of the utility of parasites as zoogeographic indicators in the region. Results showed a tight correspondence with the existing zoogeographical classification in the study region, namely two zoogeographical provinces, one of which is subdivided into two districts demonstrating the ecotonal nature of parasite assemblages from the convergence region, which were characterised by a species rich component community but depauperate and heterogeneous infracommunities. The borders of biological communities have been suggested as priority areas for conservation where a fully functioning ecosystem can be protected and parasite communities can be considered as reliable indicators to define such transitional regions.

New insight into dolphin morbillivirus phylogeny and epidemiology in the northeast Atlantic: opportunistic study in cetaceans stranded along the Portuguese and Galician coasts.

BACKGROUND: Screening Atlantic cetacean populations for Cetacean Morbillivirus (CeMV) is essential to understand the epidemiology of the disease. In Europe, Portugal and Spain have the highest cetacean stranding rates, mostly due to the vast extension of coastline. Morbillivirus infection has been associated with high morbidity and mortality in cetaceans, especially in outbreaks reported in the Mediterranean Sea. However, scarce information is available regarding this disease in cetaceans from the North-East Atlantic populations. The presence of CeMV genomic RNA was investigated by reverse transcription-quantitative PCR in samples from 279 specimens stranded along the Portuguese and Galician coastlines collected between 2004 and 2015. RESULTS: A total of sixteen animals (n = 16/279, 5.7 %) were positive. The highest prevalence of DMV was registered in striped dolphins (Stenella coeruleoalba) (n = 14/69; 20.3 %), slightly higher in those collected in Galicia (n = 8/33; 24.2 %) than in Portugal (n = 6/36; 16.7 %). CONCLUSIONS: Phylogenetic analysis revealed that, despite the low genetic distances between samples, the high posterior probability (PP) values obtained strongly support the separation of the Portuguese and Galician sequences in an independent branch, separately from samples from the Mediterranean and the Canary Islands. Furthermore, evidence suggests an endemic rather than an epidemic situation in the striped dolphin populations from Portugal and Galicia, since no outbreaks have been detected and positive samples have been detected annually since 2007, indicating that this virus is actively circulating in these populations and reaching prevalence values as high as 24 % among the Galician samples tested.

Disease surveillance of Atlantic herring: molecular characterization of hepatic coccidiosis and a morphological report of a novel intestinal coccidian.

Surveillance for pathogens of Atlantic herring, including viral hemorrhagic septicemia virus (VHSV), Ichthyophonus hoferi, and hepatic and intestinal coccidians, was conducted from 2012 to 2016 in the NW Atlantic Ocean, New Jersey, USA. Neither VHSV nor I. hoferi was detected in any sample. Goussia clupearum was found in the livers of 40 to 78% of adult herring in varying parasite loads; however, associated pathological changes were negligible. Phylogenetic analysis based on small subunit 18S rRNA gene sequences placed G. clupearum most closely with other extraintestinal liver coccidia from the genus Calyptospora, though the G. clupearum isolates had a unique nucleotide insertion between 604 and 729 bp that did not occur in any other coccidian species. G. clupearum oocysts from Atlantic and Pacific herring were morphologically similar, though differences occurred in oocyst dimensions. Comparison of G. clupearum genetic sequences from Atlantic and Pacific herring revealed 4 nucleotide substitutions and 2 gaps in a 1749 bp region, indicating some divergence in the geographically separate populations. Pacific G. clupearum oocysts were not directly infective, suggesting that a heteroxenous life cycle is likely. Intestinal coccidiosis was described for the first time from juvenile and adult Atlantic herring. A novel intestinal coccidian species was detected based on morphological characteristics of exogenously sporulated oocysts. A unique feature in these oocysts was the presence of 3 long (15.1 ± 5.1 µm, mean ±SD) spiny projections on both ends of the oocyst. The novel morphology of this coccidian led us to tentatively name this parasite G. echinata n. sp.

Molecular epidemiology and risk factors for Anisakis simplex s.l. infection in blue whiting (Micromesistius poutassou) in a confluence zone of the Atlantic and Mediterranean: Differences between A. simplex s.s. and A. pegreffii.

Our study determined parameters of parasitization of Anisakis simplex s.l. in Micromesistius poutassou in a confluence zone of the Atlantic and Mediterranean, with a total prevalence of 82%. Also, in the three seasons analyzed, high prevalence's values were found, reaching 100% in spring; however mean intensity and abundance values were higher in winter. The use of molecular techniques to differentiate between Anisakis genotypes of the larvae characterized allowed obtaining values of 99.7% Anisakis simplex s.l. (50.1% A. simplex s.s., 42.9% A. pegreffii, 7.0% A. simplex s.s. - A. pegreffii hybrids) and 0.3% A. typica. The infections found in the fish were of both single and mixed species, in all the different possible combinations. The presence of A. simplex s.l. in the viscera varied according to genotype and season. Likewise, factors associated with the presence of the parasite in the ventral or dorsal musculature were different, where A. simplex s.s. proportion was double than that of A. pegreffii. The ecology of the two sibling species with regard to their location in fish and the influence of the season were different.

Epidemiology of lobomycosis-like disease in bottlenose dolphins Tursiops spp. from South America and southern Africa.

We report on the epidemiology of lobomycosis-like disease (LLD), a cutaneous disorder evoking lobomycosis, in 658 common bottlenose dolphins Tursiops truncatus from South America and 94 Indo-Pacific bottlenose dolphins T. aduncus from southern Africa. Photographs and stranding records of 387 inshore residents, 60 inshore non-residents and 305 specimens of undetermined origin (inshore and offshore) were examined for the presence of LLD lesions from 2004 to 2015. Seventeen residents, 3 non-residents and 1 inshore dolphin of unknown residence status were positive. LLD lesions appeared as single or multiple, light grey to whitish nodules and plaques that may ulcerate and increase in size over time. Among resident dolphins, prevalence varied significantly among 4 communities, being low in Posorja (2.35%, n = 85), Ecuador, and high in Salinas, Ecuador (16.7%, n = 18), and Laguna, Brazil (14.3%, n = 42). LLD prevalence increased in 36 T. truncatus from Laguna from 5.6% in 2007-2009 to 13.9% in 2013-2014, albeit not significantly. The disease has persisted for years in dolphins from Mayotte, Laguna, Salinas, the Sanquianga National Park and Bahía Málaga (Colombia) but vanished from the Tramandaí Estuary and the Mampituba River (Brazil). The geographical range of LLD has expanded in Brazil, South Africa and Ecuador, in areas that have been regularly surveyed for 10 to 35 yr. Two of the 21 LLD-affected dolphins were found dead with extensive lesions in southern Brazil, and 2 others disappeared, and presumably died, in Ecuador. These observations stress the need for targeted epidemiological, histological and molecular studies of LLD in dolphins, especially in the Southern Hemisphere.

Histopathological assessment of liver and gonad pathology in continental slope fish from the northeast Atlantic Ocean.

The deep-sea environment is a sink for a wide variety of contaminants including heavy metals and organic compounds of anthropogenic origin. Life history traits of many deep-water fish species including longevity and high trophic position may predispose them to contaminant exposure and subsequent induction of pathological changes, including tumour formation. The lack of evidence for this hypothesis prompted this investigation in order to provide data on the presence of pathological changes in the liver and gonads of several deep-water fish species. Fish were obtained from the north east region of the Bay of Biscay (north east Atlantic Ocean) by trawling at depths between 700 and 1400 m. Liver and gonad samples were collected on board ship and fixed for histological processing and subsequent examination by light microscopy. Hepatocellular and nuclear pleomorphism and individual cases of ovotestis and foci of cellular alteration (FCA) were detected in black scabbardfish (Aphanopus carbo). Six cases of FCA were observed in orange roughy (Hoplostethus atlanticus) (n = 50) together with a single case of hepatocellular adenoma. A wide variety of inflammatory and degenerative lesions were found in all species examined. Deep-water fish display a range of pathologies similar to those seen in shelf-sea species used for international monitoring programmes including biological effects of contaminants. This study has confirmed the utility of health screening in deep-water fish for detecting evidence of prior exposure to contaminants and has also gained evidence of pathology potentially associated with exposure to algal toxins.