Occurrence of salmonid alphavirus and piscine orthoreovirus-1 infections in migrating salmon (Salmo salar L.) post-smolt in western Norway.

Viral diseases are a serious problem in Atlantic salmon (Salmo salar L.) farming in Norway, often leading to reduced fish welfare and increased mortality. Disease outbreaks in salmon farms may lead to spread of viruses to the surrounding environment. There is a public concern that viral diseases may negatively affect the wild salmon populations. Pancreas disease (PD) caused by salmonid alphavirus (SAV) and heart and skeletal muscle inflammation (HSMI) caused by piscine orthoreovirus-1 (PRV-1) are common viral diseases in salmon farms in western Norway. In the current study, we investigated the occurrence of SAV and PRV-1 infections in 651 migrating salmon post-smolt collected from three fjord systems (Sognefjorden, Osterfjorden and Hardangerfjorden) located in western Norway in 2013 and 2014 by real-time RT-PCR. Of the collected post-smolts, 303 were of wild origin and 348 were hatchery-released. SAV was not detected in any of the tested post-smolt, but PRV-1 was detected in 4.6% of them. The Ct values of PRV-1 positive fish were usually high (mean 32.0; range: 20.1-36.8). PRV-1 prevalence in post-smolts from the three fjords was 6.1% in Sognefjorden followed by 4.8% in Osterfjorden and 2.3% in Hardangerfjorden. The prevalence PRV-1 was significantly higher in wild (6.9%) compared to hatchery-released post-smolt (2.6%). The occurrence of PRV-1 infection in the fish was lowest in the Hardangerfjorden which has the highest fish farming intensity. Our results suggest that SAV infection are uncommon in migrating smolt while PRV-1 infection can be detected at low level. These findings suggest that migrating smolts were at low risk from SAV or PRV-1 released from salmon farms located in their migration routes in 2013 and 2014.

Non-lethal detection of Eubothrium crassum (Cestoda) in farmed Atlantic salmon, Salmo salar, using anal swabs and real-time PCR.

Detection of intestinal parasites in fish typically requires autopsy, resulting in the sacrifice of the fish. Here, we describe a non-lethal method for detecting the tapeworm Eubothrium crassum in fish using anal swabs and real-time PCR detection. Two assays were developed to detect cytochrome oxidase I (COI) mitochondrial DNA and 18S ribosomal DNA sequences of E. crassum, respectively. The assays were tested on swab samples from confirmed pathogen free Atlantic salmon (Salmo salar L.) and on samples from farmed Atlantic salmon, where the presence and intensity of parasites had been established through autopsy. The COI assay was shown to be specific to E. crassum, while the 18S assay also amplified the closely related E. salvelini, a species infecting Arctic charr (Salvelinus alpinus L.) in freshwater. The COI assay detected E. crassum in all field samples regardless of parasite load while the 18S assay failed to detect the parasite in two samples. The results thus demonstrates that this non-lethal approach can effectively detect E. crassum and can be a valuable tool in assessing the prevalence of infection in farmed salmon, aiding in treatment decisions and evaluating treatment effectiveness.

Most of the escaped farmed salmon entering a river during a 5-year period were infected with one or more viruses.

Disease interactions between farmed and wild populations have been poorly documented for most aquaculture species, in part due to the complexities to study this. Here, we tested 567 farmed Atlantic salmon escapees, captured in a Norwegian river during 2014-2018, for five viral infections that are prevalent in global salmonid aquaculture. Over 90% of the escapees were infected with one or more viruses. Overall prevalences were: 75.7% for piscine orthoreovirus (PRV-1), 43.6% for salmonid alphavirus (SAV), 31.2% for piscine myocarditis virus (PMCV), 1.2% for infectious pancreatic necrosis virus (IPNV) and 0.4% for salmon anaemia virus (ISAV). A significantly higher prevalence of PMCV infection was observed in immature compared to mature individuals. The prevalence of both SAV and PMCV infections was higher in fish determined by fatty acid profiling to be 'recent' as opposed to 'early' escapees that had been in the wild for a longer period of time. This is the first study to establish a time-series of viral infection status of escapees entering a river with a native salmon population. Our results demonstrate that farmed escapees represent a continuous source of infectious agents which could potentially be transmitted to wild fish populations.

First identification of mycobacteriosis in Atlantic mackerel (Scomber scombrus).

Mycobacterium infection in fish is a well-known disease problem globally, mainly in the farming of ornamental fish or fish for food. Less is known about the prevalence, distribution and the effects such infections have on wild fish species. Presumptive mycobacteriosis has previously been observed in Atlantic mackerel (Scomber scombrus). Since 2018, there has been an increase in reports of granulomatous kidney disease in Atlantic mackerel with the suspicion of this being mycobacteriosis. A total of six individuals were sent to the Institute of Marine Research for further examination. They were caught in the Nordic Sea by either commercial fishing vessels or during the International Ecosystem Summer Survey in the Nordic Seas (IESSNS research cruise) between 2018 and 2020. Samples for both histological and molecular analysis were collected. Here, we detect a likely novel Mycobacterium species in tissue samples from Atlantic mackerel with this condition, on the basis of rDNA and protein gene sequences. The same unnamed bacterium seems to have been found in some Pacific marine fishes. The macroscopic and histological manifestation of the disease is described. Over the past years, there has been an increase in reports of mycobacteriosis worldwide and climate change has been suggested as one of the driving forces as these bacteria prefer warm water.

Infection cycle of Marteilia pararefringens in blue mussels Mytilus edulis in a heliothermic marine oyster lagoon in Norway.

Agapollen is a traditional heliothermic marine oyster lagoon in western Norway, representing the northernmost site of any Marteilia sp. protists detected in Europe. The semi-closed lagoon is a unique site to study the life cycle and development of M. pararefringens in naïve mussels. Two baskets with uninfected mussels were deployed in the lagoon outlet in May and October 2018, respectively, and sampled every 6 wk. The parasite was first detected in the mussels by PCR in early July and by histology in late August. By then, M. pararefringens had developed into mature stages, indicating a rapid development during mid-summer. Sporulation occurred during autumn. Mussels deployed in October never became infected, indicating that transmission was restricted to the warmest period of the year. Pronounced pathology was observed in infected mussels, including degenerated digestive tubules and infiltration of haemocytes. Mussel mortality was observed in the baskets, but whether this was due to infections of M. pararefringens or other environmental factors could not be determined. Plankton samples from the lagoon were also collected for PCR analysis. These samples, dominated by copepods, were positive for M. pararefringens in summer. In sorted samples, M. pararefringens was detected in the Acartia spp. and Paracartia grani fractions between July and October. These plankton copepods are therefore potentially involved in the life cycle of M. pararefringens.

Distribution of Kudoa thyrsites (Cnidaria, Myxozoa) myoliquefactive stages in Northeast Atlantic mackerel (Scomber scombrus) inferred from qPCR and histology.

Kudoa thyrsites is a myxosporean parasite (Cnidaria, Myxozoa) that infects the skeletal and cardiac muscle of Northeast Atlantic (NEA) mackerel (Scomber scombrus). Heavy infections are associated with post-mortem myoliquefaction of the host skeletal muscle which reduces the quality of the fish product. The biological infection characteristics of the parasite in NEA mackerel are poorly known. This study examined the distribution of K. thyrsites in various organs of NEA mackerel from the northern North Sea, and elucidates the relationship between density of infection, developmental stage and parasite distribution in the musculature, and the extent of visible flesh myoliquefaction. Quantitative polymerase chain reaction (qPCR) data showed that K. thyrsites is unevenly distributed in the somatic musculature of the fish host, with highest density in the anterior ventral muscle sections-the belly flaps. A weak positive correlation was observed between the level of myoliquefaction and the parasite density in the fish host muscle. This relationship was also reflected by the amount and distribution of parasite developmental stages seen during histological examinations. Histological findings indicate an association between the dispersion of free myxospores and the level of myoliquefaction of the fish host muscle. Visceral organs were also found infected using qPCR, although at lower densities compared to the musculature.

The salmon louse genome: Copepod features and parasitic adaptations.

Copepods encompass numerous ecological roles including parasites, detrivores and phytoplankton grazers. Nonetheless, copepod genome assemblies remain scarce. Lepeophtheirus salmonis is an economically and ecologically important ectoparasitic copepod found on salmonid fish. We present the 695.4 Mbp L. salmonis genome assembly containing ≈60% repetitive regions and 13,081 annotated protein-coding genes. The genome comprises 14 autosomes and a ZZ-ZW sex chromosome system. Assembly assessment identified 92.4% of the expected arthropod genes. Transcriptomics supported annotation and indicated a marked shift in gene expression after host attachment, including apparent downregulation of genes related to circadian rhythm coinciding with abandoning diurnal migration. The genome shows evolutionary signatures including loss of genes needed for peroxisome biogenesis, presence of numerous FNII domains, and an incomplete heme homeostasis pathway suggesting heme proteins to be obtained from the host. Despite repeated development of resistance against chemical treatments L. salmonis exhibits low numbers of many genes involved in detoxification.

Lower levels of Persistent Organic Pollutants, metals and the marine omega 3-fatty acid DHA in farmed compared to wild Atlantic salmon (Salmo salar).

Contaminants and fatty acid levels in farmed- versus wild Atlantic salmon have been a hot topic of debate in terms of food safety. The present study determined dioxins (polychlorinated dibenzo-p-dioxin and dibenzofuran), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs), metals and fatty acids in wild and farmed Atlantic salmon. Contaminant levels of dioxins, PCBs, OCPs (DDT, dieldrin, lindane, chlordane, Mirex, and toxaphene), and mercury were higher in wild salmon than in farmed salmon, as were the concentrations of the essential elements selenium, copper, zinc and iron, and the marine omega-3 fatty acid docosahexaenoic acid (DHA). PBDE, endosulfan, pentachlorobenzene, hexachlorobenzene, cadmium and lead levels were low and comparable in both wild and farmed fish, and there was no significant difference in the marine omega-3 fatty acid eicosapentaenoic acid (EPA) concentration. The total fat content was significantly higher in farmed than wild salmon due to a higher content of both saturated and monounsaturated fatty acids, as well as a higher content of omega-6 fatty acids. The omega-3 to omega-6 fatty acid ratio was considerably lower in farmed than wild salmon due to the high level of omega-6 fatty acids. Contaminant concentrations in Atlantic salmon were well below maximum levels applicable in the European Union. Atlantic salmon, both farmed and wild, is a good source of EPA and DHA with a 200g portion per week contributing 3.2g or 2.8g respectively, being almost twice the intake considered adequate for adults by the European Food Safety Authority (i.e. 250mg/day or 1.75g/week).

High nervous necrosis virus (NNV) diversity in wild wrasse (Labridae) in Norway and Sweden.

Wild goldsinny wrasse Ctenolabrus rupestris, corkwing wrasse Symphodus melops and ballan wrasse Labrus bergylta were collected at 8 sampling sites in Sweden and Norway during summer 2014. Brain tissue from 466 wrasses were analyzed for nervous necrosis virus (NNV) infections by real-time RT-PCR, and positive samples were subjected to sequencing and phylogenetic analysis of partial segments of the RNA2 and RNA1 genes. This study shows that NNV is present in wild ballan, corkwing and goldsinny wrasse along the coastline of Sweden and Norway. The overall prevalence in the sampled labrids was 6.7%. Prevalence was 6.4% in goldsinny, 6.3% in corkwing and 18% in ballan wrasse. The wrasse RNA2 NNV sequences revealed high genetic variability and were divided into 3 clusters within the cold water barfin flounder NNV (BFNNV) and warm water cluster red-spotted grouper NNV (RGNNV) genogroups. Within the BFNNV genogroup, wrasse NNVs clustered in 2 sub-genogroups, with grey mullet NNV (GMNNV) and with Atlantic halibut NNV (AHNNV). These groups were previously dominated by virus originating from Atlantic cod Gadus morhua and Atlantic halibut Hippoglossus hippoglossus from the northeast Atlantic. The presence of NNV in wild wrasse and the surprising high genetic variability observed in this study should be considered before moving wild-caught wrasse between geographically distant sites. The results show that use of wild-caught wrasse as brood fish in wrasse farming represents a risk of introducing NNV into aquaculture.

Occurrence of salmonid alphavirus (SAV) and piscine orthoreovirus (PRV) infections in wild sea trout Salmo trutta in Norway.

Viral diseases represent a serious problem in Atlantic salmon (Salmo salar L.) farming in Norway. Pancreas disease (PD) caused by salmonid alphavirus (SAV) and heart and skeletal muscle inflammation (HSMI) caused by piscine orthoreovirus (PRV) are among the most frequently diagnosed viral diseases in recent years. The possible spread of viruses from salmon farms to wild fish is a major public concern. Sea trout S. trutta collected from the major farming areas along the Norwegian coast are likely to have been exposed to SAV and PRV from farms with disease outbreaks. We examined 843 sea trout from 4 counties in Norway for SAV and PRV infections. We did not detect SAV in any of the tested fish, although significant numbers of the trout were caught in areas with frequent PD outbreaks. Low levels of PRV were detected in 1.3% of the sea trout. PRV-infected sea trout were caught in both salmon farming and non-farming areas, so the occurrence of infections was not associated with farming intensity or HSMI cases. Our results suggest that SAV and PRV infections are uncommon in wild sea trout. Hence, we found no evidence that sea trout are at risk from SAV or PRV released from salmon farms.

A new intracellular bacterium, Candidatus Similichlamydia labri sp. nov. (Chlamydiaceae) producing epitheliocysts in ballan wrasse, Labrus bergylta (Pisces, Labridae).

Certain wrasse species (Labridae) are used as cleaner fish in salmon farms on the Norwegian coast, reducing salmon louse intensities. The pathogen repertoire of wrasse in Norway is poorly known, and the objective of the present study is to describe a novel intracellular bacterium detected in Norwegian Labrus bergylta. Histological examination of gill tissues from ballan wrasse, L. bergylta, revealed epitheliocysts occurring basally to the secondary lamellae in the interlamellar epithelium. Ultrastructurally, these had bacteria-filled inclusions with thickened membranes and radiating ray-like structures (actinae). 16S rRNA gene sequences from the gill bacteria showed the highest (97.1 %) similarity to Candidatus Similichlamydia latridicola from the gills of the latrid marine fish Latris lineata in Australia and 94.9 % similarity to Candidatus Actinochlamydia clariae, causing epitheliocystis in the freshwater catfish Clarias gariepinus in Uganda. A total of 47 gill samples from L. bergylta from Western Norway were screened by real time RT-PCR with an assay targeting Candidatus Actinochlamydiaceae 16S rRNA. Prevalence was 100 %. We propose the name Candidatus Similichlamydia labri sp. nov. for this new agent producing gill epitheliocysts in L. bergylta.

Characterization of 'Candidatus Syngnamydia salmonis' (Chlamydiales, Simkaniaceae), a bacterium associated with epitheliocystis in Atlantic salmon (Salmo salar L.).

Two Chlamydiales have previously been found to infect Atlantic salmon (Salmo salar L.), Candidatus Piscichlamydia salmonis and Candidatus Clavichlamydia salmonicola. Both develop intracellularly in cyst-like inclusions in gill cells, generally referred to as epitheliocysts. Here, we present evidence for the association of a novel species of Chlamydiales with epitheliocystis in Atlantic salmon. Based on its partial 16S rRNA gene sequence, it is a new member of the family Simkaniaceae, and a 95.7 % identity to the type species Candidatus Syngnamydia venezia suggests inclusion in the candidate genus Syngnamydia. The presence of the bacterium in epitheliocysts in gills of Atlantic salmon was demonstrated by RNA-RNA hybridization. Ultrastructurally, the novel bacterium produces pleomorphic reticulate bodies and elementary bodies (EBs) with a characteristic morphology. The EBs are short rods with a terminal disc-like cap area, a sub-apical spherical vacuole-like electron-lucent structure and a post-equatorial nucleoid. We propose the name Candidatus Syngnamydia salmonis for this new agent from epitheliocysts in seawater-reared salmon .

Untangling the Derogenes varicus species complex in Scandinavian waters and the Arctic: description of Derogenes abba n. sp. (Trematoda, Derogenidae) from Hippoglossoides platessoides and new host records for D. varicus (Müller, 1784) sensu stricto.

Several studies have shown that the euryxenic trematode Derogenes varicus (Müller, 1784) represents a species complex. Four lineages have been designated (DV1-4) with the DV1 clade corresponding to D. varicus sensu stricto. Herein, we investigate newly collected specimens of D. varicus sensu lato from Scandinavian and Arctic waters using integrative taxonomy. The trematodes were collected from Melanogrammus aeglefinus, Eutrigla gurnardus, Trachinus draco, and Merluccius merluccius off the Atlantic coast of Sweden and from Hippoglossoides platessoides from Arctic Svalbard. 28S sequences of derogenids from Sweden were identical to D. varicus sensu stricto, confirming its euryxeny. The 28S sequences of Derogenes sp. from H. platessoides were identical to Derogenes DV2 and differed from D. varicus sensu stricto by 3% and from Derogenes DV3 by 2%. The 28S sequence divergences of Derogenes sp. from H. platessoides with D. ruber and D. lacustris were 3 and 10%, respectively. ITS2 and cox1 divergences between Derogenes sp. from H. platessoides and other Derogenes species/lineages were at levels of interspecific differences. The species from H. platessoides is described here as D. abba n. sp. We also examined the type material of Progonus muelleri (Levinsen, 1881), the type and only species of the genus Progonus, with redescription and designations of paralectotypes. Based on specimens from Theodor Odhner's collections at the Swedish Museum of Natural History, SMNH, Stockholm, we provide novel morphological and anatomical data for D. varicus sensu lato species complex. Lastly, we investigated Arthur Looss's "lost collection" of Trematodes at the SMNH and characterised a putative species Derogenes sp. "limula".

Title: Démêler le complexe d'espèces Derogenes varicus dans les eaux scandinaves et arctiques : description de Derogenes abba n. sp. (Trematoda, Derogenidae) parasite d'Hippoglossoides platessoides et nouveaux signalements d'hôtes pour D. varicus (Müller, 1784) sensu stricto. Abstract: Plusieurs études ont montré que le trématode euryxene Derogenes varicus (Müller, 1784) représente un complexe d'espèces. Quatre lignées ont été désignées (DV1­4), le clade DV1 correspondant à D. varicus sensu stricto. Ici, nous étudions des spécimens nouvellement collectés de D. varicus sensu lato dans les eaux scandinaves et arctiques en utilisant la taxonomie intégrative. Les trématodes ont été collectés de Melanogrammus aeglefinus, Eutrigla gurnardus, Trachinus draco et Merluccius merluccius au large de la côte atlantique de la Suède et d'Hippoglossoides platessoides du Svalbard arctique. Les séquences 28S des Derogenidae de Suède étaient identiques à D. varicus sensu stricto, confirmant son euryxénie. Les séquences 28S de Derogenes sp. de H. platessoides étaient identiques à Derogenes DV2 et différaient de D. varicus sensu stricto par 3% et de Derogenes DV3 par 2%. Les divergences des séquence 28S de Derogenes sp. de H. platessoides avec D. ruber et D. lacustris étaient respectivement de 3 et 10%. Les divergences ITS2 et cox1 entre Derogenes sp. de H. platessoides et d'autres espèces/lignées de Derogenes se situaient à des niveaux de différences interspécifiques. L'espèce de H. platessoides est décrite ici comme Derogenes abba n. sp. Nous avons également examiné le matériel type de Progonus muelleri (Levinsen, 1881), type et seule espèce du genre Progonus, avec une redescription et des désignations de paralectotypes. Sur la base de spécimens des collections de Theodor Odhner au Musée suédois d'histoire naturelle (SMNH), Stockholm, nous fournissons de nouvelles données morphologiques et anatomiques sur le complexe d'espèces de D. varicus sensu lato. Enfin, nous avons étudié la « collection perdue ¼ de Trématodes d'Arthur Looss au SMNH et caractérisé une espèce putative, Derogenes sp. « limula ¼.

Post-mortem 'soft flesh' in three commercial fish species from off Atlantic Morocco associated with the myxosporean parasites Kudoa thyrsites and K. encrasicoli (Myxozoa).

Small pelagic fishes represent one of the most important food resources off the Northwest coast of Africa. Despite their economic significance, little is known about the infections with flesh invading myxosporean parasites of genus Kudoa (Cnidaria, Myxozoa). Heavy infections in the flesh may be associated with post-mortem myoliquefaction, commonly known as 'soft flesh'. This condition may reduce the quality and marketability of the fish fillet, resulting in both economic losses to the fishing industry and loss of consumer confidence. In this study, we investigated Kudoa-induced 'soft flesh' occurrence in European anchovy Engraulis encrasicolus, European pilchard Sardina pilchardus, and Atlantic chub mackerel Scomber colias caught in 2019 off the Moroccan Atlantic coast. Five hundred specimens of each fish species were examined for 'soft flesh' by texture testing and visual inspection 48 h post-catch. 'Soft flesh' occurred in 0.2 % of the European anchovies, 1.4 % of the European pilchard, and in 4.4 % of the Atlantic chub mackerel. Microscopic examination of muscle samples revealed that 'soft flesh'-affected fish were infected with myxospores of K. thyrsites-like morphotype. Analysis of the kudoid SSU rDNA sequence obtained from European pilchard and the Atlantic chub mackerel identified these as K. thyrsites (100 % identity), whereas analysis of the sequence from European anchovy identified the presence of K. encrasicoli (100 % identity). Even if there are no known human health consequences associated with the ingestion of these Kudoa species, the unsightly appearance of some infected fillets is a food quality issue, that can eventually lead to reduced marketability and value.

Sphaeromyxa artedielli sp. n. (Myxozoa: Sphaeromyxidae), a parasite of sculpins (Cottidae) in northern Norway.

Sphaeromyxa artedielli sp. n. is described from the gall bladder of the Atlantic hookear sculpin Artediellus atlanticus Jordan et Evermann (Cottidae; type host) from northern Norway. The parasite was also found to infect Triglops murrayi Günther (Cottidae). Spores are produced in disporic pansporoblasts in large flat plasmodia. Spores are straight and fusiform with truncated ends, and measure 16.5-18.7 microm x 4.9-6.2 microm. Valves are thick, striated and suture line is straight. Two equal ovoid polar capsules measure 4.2-6.8 microm x 2.9-4.4 microm and contain irregularly folded polar filaments. Distinctive features include spore shape and size, spore length/width relationship, striated valves, equal polar capsules and a short intercapsular distance. Sphaeromyxa bonaerensis Timi et Sardella, 1998, Sphaeromyxa cannolii Sears, Anderson et Greiner, 2011, and Sphaeromyxa sevastopoli Naidenova, 1970 produce straight spores with truncated ends that are of similar length as those of the new species. Sphaeromyxa cannolii differs in showing smooth spores with unequal polar capsules. The new species differs from S. bonaerensis and S. sevastopoli in significantly wider spores and polar capsules. Sphaeromyxa balbianii Thélohan, 1892, a species originally described with significantly smaller spores than S. artedielli sp. n., has previously been recorded from T. murrayi. We show that S. artedielli sp. n. differs from S. balbianii from the type host Gaidropsarus vulgaris (Cloquet) by its SSU rDNA sequence, and suggest that Atlantic records of Sphaeromyxa spp. from T. murrayi represent S. artedielli sp. n. The closest relative to S. artedielli sp. n. according to the SSU rDNA sequences, S. longa Dunkerly, 1921, differs clearly by spore size and shape. In the SSU rDNA-based phylogenetic analyses, S. artedielli sp. n. groups with other Sphaeromyxa spp. with straight spores and truncated ends in a clade that represents a sister-group to Sphaeromyxa spp. with arcuate spores and rounded ends. Our results indicate that an SSU rDNA pseudogene is present in S. balbianii.

A parvicapsulid (Myxozoa) infecting Sprattus sprattus and Clupea harengus (Clupeidae) in the Northeast Atlantic uses Hydroides norvegicus (Serpulidae) as invertebrate host.

A myxosporean producing actinospores of the tetractinomyxon type in Hydroides norvegicus Gunnerus (Serpulidae) in Denmark was identified as a member of the family Parvicapsulidae based on small-subunit ribosomal DNA (SSU rDNA) sequences. Myxosporean samples from various Danish and Norwegian marine fishes were examined with primers that detect the novel myxosporean. Sprattus sprattus (Linnaeus) and Clupea harengus Linnaeus (Teleostei, Clupeidae) were found to be infected. The sequences of this parvicapsulid from these hosts were consistently slightly different (0.8% divergence), but both these genotypes were found in H. norvegicus. Disporic trophozoites and minute spores of a novel myxosporean type were observed in the renal tubules of some of the hosts found infected through PCR. The spores appear most similar to those of species of Gadimyxa Køie, Karlsbakk et Nylund, 2007, but are much smaller. The actinospores of the tetractinomyxon type from H. norvegicus have been described previously. In GenBank, the SSU rDNA sequences of Parvicapsulidae gen. sp. show highest identity (82%) with Parvicapsula minibicornis Kent, Whitaker et Dawe, 1997 infecting salmonids (Oncorhynchus spp.) in fresh water in the western North America. A phylogenetic analysis places P. minibicornis and Parvicapsulidae gen. sp. in a sister clade to the other parvicapsulids (Parvicapsula spp. and Gadimyxa spp.).

Resurrection of genus Phocanema Myers, 1959, as a genus independent from Pseudoterranova Mozgovoi, 1953, for nematode species (Anisakidae) parasitic in pinnipeds and cetaceans, respectively.

Species of the genus Pseudoterranova, infect kogiid cetaceans and pinnipeds. However, there is mounting molecular evidence that those from cetaceans and pinnipeds are not congeneric. Here, we provide further evidence of the non-monophyly of members of Pseudoterranova from phylogenetic analyses of the conserved nuclear LSU rDNA gene, entire ITS rDNA region and mtDNA cox2 gene, and identify morphological characters that may be used to distinguish the members of the two clades. We propose the resurrection of the genus Phocanema, with Ph. decipiens (sensu stricto) as the type species, to encompass Ph. decipiens, Ph. azarasi, Ph. bulbosa, Ph. cattani and Ph. krabbei, all parasites of pinnipeds. We propose to restrict the conception of genus Pseudoterranova, which now harbours two species infecting kogiid whales; Ps. kogiae (type species) and Ps. ceticola. Members of the genera Phocanema and Pseudoterranova differ by the shape and orientation of the lips, relative tail lengths, adult size, type of final host (pinniped vs. cetacean) and phylogenetic placement based on nuclear rDNA and mtDNA cox2 sequences.