Diseases of aquatic organisms最新文献

{"title":"Non-lethal detection of the invasive American eel parasite Anguillicola crassus.","authors":"Danielle R Lavoie, Kenneth Oliveira","doi":"10.3354/dao03849","DOIUrl":"https://doi.org/10.3354/dao03849","url":null,"abstract":"<p><p>The invasive species Anguillicola crassus is a nematode that infects the swimbladders of anguillid eels. Heavy, repeated infections cause the swimbladder to become thickened and scarred, which can alter swimbladder gas volume, increase energy demands of buoyancy regulation, and influence normal function. Silver-phase (sexually maturing) eels migrate up to thousands of kilometers to the Sargasso Sea to reproduce, and increased energetic requirements may be detrimental to migration and breeding success. Currently, the best practice to confirm A. crassus infection is to dissect an eel and examine the swimbladder. We used a portable digital X-ray system to determine the presence of A. crassus in American eels Anguilla rostrata. Silver-phase eels were anesthetized and radiographed. Post-imaging, individuals were dissected to compare the contents of the swimbladder to the radiographs. Infections appeared opaque on radiographs. Results showed no false positives and an accuracy of 74.8%. Out of 193 X-rayed eels, 107 contained parasites; 27 infections were undetectable on radiographs (false negatives). Detection was influenced by the intensity, size, and location of parasites within the swimbladder. This digital X-ray method is a quick and non-lethal process that could be incorporated into existing monitoring programs.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"161 ","pages":"87-93"},"PeriodicalIF":1.1,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143662788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metastatic gastric adenocarcinoma in a grey seal Halichoerus grypus: clinicopathological and immunohistochemical characterization.","authors":"Gonçalo Nogueira Marques, Bernat Marti-Garcia, Miriam Oliveira Leal, Nuno Urbani Ramos da Silva, Carla Anne Flanagan, Alejandro Suárez-Bonnet","doi":"10.3354/dao03845","DOIUrl":"https://doi.org/10.3354/dao03845","url":null,"abstract":"<p><p>A 33 yr old female grey seal Halichoerus grypus presented with inappetence and progressive weight loss. Medical management included blood analysis, imaging, and fecal evaluation, along with multimodal supportive therapy, which periodically improved the overall medical condition. Six months after the initial presentation, the clinical condition deteriorated significantly, including severe hyporexia, hematemesis, and marked neutrophilic leukocytosis, which led to the decision to euthanise based on welfare grounds. Necropsy findings included severe thickening of the distal esophagus, cardia, and proximal gastric fundus, as well as multiple nodular to cystic structures over the stomach's serosa, omentum, and mesentery. Histologically, a mucinous gastric adenocarcinoma was diagnosed, with metastasis to the gastric lymph nodes and prominent carcinomatosis involving the omentum, mesentery, and diaphragm. Immunohistochemically, the gastric adenocarcinoma was positive for cytokeratin AE1/AE3, weakly positive for COX-2 and E-cadherin, and negative for vimentin. The Ki-67 proliferative index was low (0.8). Although rare, this case offers further insights into the clinical presentation, histopathology, and immunohistochemical profile of gastric tumors in pinnipeds.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"161 ","pages":"125-131"},"PeriodicalIF":1.1,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143662783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spirometry as a diagnostic tool to assess respiratory health in beached bottlenose dolphins Tursiops spp.","authors":"A Fahlman, B Sterba-Boatwright, F Cauture, J Sweeney, R Stone","doi":"10.3354/dao03843","DOIUrl":"https://doi.org/10.3354/dao03843","url":null,"abstract":"<p><p>In this study, we used a dataset including 42 individual bottlenose dolphins (Tursiops spp.) to determine the reliability of lung function testing as a method for assessing respiratory health. Each dolphin was trained to beach voluntarily, allowing researchers to measure respiratory flow in a controlled, beached state. From the collected respiratory flow data, alongside timing parameters, we extracted 18 specific variables, supplemented by additional factors such as body mass, age, and sex. These variables were hypothesized to serve as potential variables for identifying respiratory compromise. A model was developed that reduced the number of predictive variables, showing that 4 specific variables were particularly effective, yielding an accuracy of 88.4% in determining whether a dolphin was free from respiratory disease. This high level of accuracy underscores the potential of lung function testing as a diagnostic tool in the context of stranded dolphins, where rapid, non-invasive methods are crucial for assessing health status. These results suggest that lung function testing provides a non-invasive and efficient method for evaluating respiratory health in stranded dolphins and supports the use of lung function assessments in wildlife management and conservation. By enabling early detection of respiratory issues, this approach can enhance the success of rehabilitation efforts, potentially improving the survival rates of dolphins that have stranded, which is often a critical concern in marine conservation initiatives.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"161 ","pages":"113-124"},"PeriodicalIF":1.1,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143662795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel echinostomatoid trematode (Himasthlidae) parasitising an edible snail, Euspira gilva (Gastropoda), in the East China Sea.","authors":"Na Ying, Yuan Wang, Bo Qin, Xuefeng Song, Liguo Yang, Yanqing Wu, Zhixing Su, Huijuan Chen, Wenhong Fang","doi":"10.3354/dao03842","DOIUrl":"https://doi.org/10.3354/dao03842","url":null,"abstract":"<p><p>A trematode was identified in the gastropod Euspira gilva in the East China Sea. The intensity of infection in individual snails ranged from light to heavy, with an overall prevalence of 83.1% (n = 219). Given the observed decline in the E. gilva population, a series of diagnostic techniques were employed to identify the trematode and investigate the damage caused. These included smear observation, histopathological observation and molecular analysis. The results of the smear observation and histological sections indicated that this trematode only infected the gonad, and the presence of the larval rediae stage in the parasitized tissue was observed. The 28S rDNA sequence was used for molecular identification, which revealed a homology of 92.1-95.8% with the Echinostomatoidea superfamily and a genetic distance of 0.042-0.093 with existing genera within the superfamily. The considerable genetic distance between this trematode and other genera of the superfamily indicates that it cannot be clustered into any genus at present. The phylogenetic tree also demonstrated that this trematode constituted a discrete branch, albeit one that was closely related to Himasthla and Acanthoparyphium spp. within the family Himasthlidae. Based on the aforementioned data and in consideration of the observed decline in wild populations, we postulate that this echinostomatoid trematode represents a potential threat to E. gilva. This is the first report on trematodes in E. gilva.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"161 ","pages":"95-101"},"PeriodicalIF":1.1,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143662792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tissue tropism and molecular data of Myxobolus ellipsoides ex S. cephalus (Myxozoa: Myxobolidae) infecting European chub Squalius cephalus.","authors":"Eva Lewisch, Josef Harl, Hans-Peter Fuehrer, Licha N Wortha, Kurt Pinter, Mansour El-Matbouli","doi":"10.3354/dao03841","DOIUrl":"https://doi.org/10.3354/dao03841","url":null,"abstract":"<p><p>In the River Traun in Austria, diseased European chub Squalius cephalus were observed for several years. In 2019, an investigation of the condition revealed the presence of several myxozoan species in different tissues, without evidence of other pathogens. The most prevalent and abundant myxozoan parasite in the different organs was Myxobolus ellipsoides ex S. cephalus, a parasite formerly only reported to infect the fin of European chub. To further investigate tissue tropism and molecular data of this parasite, samples from 11 different organs of 13 European chub were collected 1 yr later and examined with various methods. Myxospore morphology was assessed by microscopy and compared to the literature. A specific PCR protocol targeting the 18S rRNA gene of M. ellipsoides ex S. cephalus and subsequent sequence analyses detected 11 different 18S variants clustering into 2 groups. To differentiate M. ellipsoides ex S. cephalus unambiguously from other myxozoan parasites in the tissues, histological methods and in situ hybridization with a species-specific probe targeting the 18S rRNA of the parasite were applied. DNA of M. ellipsoides ex S. cephalus could be detected by PCR in each of the examined fish in at least 2 of the sampled organs, but not in any blood sample. In 2 fish, M. ellipsoides ex S. cephalus myxospores were detected in plasmodia in the kidney. Our findings present new data regarding tissue tropism and molecular diversity of M. ellipsoides ex S. cephalus in European chub and provide a basis for further studies investigating possible health impacts by this parasite.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"161 ","pages":"103-112"},"PeriodicalIF":1.1,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143662798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flat oysters Ostrea edulis are not susceptible to Marteilia pararefringens infection.","authors":"Mats Bøgwald, Cecilie Skår, Stein Mortensen","doi":"10.3354/dao03839","DOIUrl":"https://doi.org/10.3354/dao03839","url":null,"abstract":"<p><p>The host specificity of Marteilia pararefringens is under discussion after its suggested reseparation from the flat oyster pathogen M. refringens in 2018. In Norway, M. pararefringens has been detected in mussels Mytilus spp. sampled from several isolated, small heliothermic ponds (polls) that, at least on the western coast, inhabit some of the last reproducing flat oyster populations. M. refringens has never been detected in Norway. The polls have a limited water exchange, and their uniquely warm temperature can result in high M. pararefringens prevalence and infection intensities, representing unique sites to study the susceptibility of flat oysters to this parasite. We have sampled flat oysters and mussels from all known M. pararefringens sites along the Norwegian coast. All flat oysters and mussels were screened by histology and PCR. Furthermore, to study the potential effect of natural resistance breeding of local flat oysters subjected to repetetive M. pararefringens cycles, we deployed naïve flat oysters from a known Marteilia-free poll to Agapollen, where the parasite has had consistent infection cycles since its discovery in 2016. Naïve mussels were deployed simultaneously in 2 separate years to verify that the flat oysters were subjected to at least 2 transmission cycles. M. pararefringens was not detected in any flat oysters in any poll, local or naïve, despite presence in the mussel populations. Our results show that the European flat oyster Ostrea edulis is not a susceptible host for M. pararefringens.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"161 ","pages":"75-85"},"PeriodicalIF":1.1,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143467131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isolation and characterization of viral hemorrhagic septicemia virus from farmed bastard halibut.","authors":"Ye Xu, Taishan Tang, Jing Wang, Weiwei Dou, Na Wang, Yi Zhou, Hongan Duan","doi":"10.3354/dao03840","DOIUrl":"https://doi.org/10.3354/dao03840","url":null,"abstract":"<p><p>Viral hemorrhagic septicemia virus (VHSV) was detected and identified in healthy bastard halibut Paralichthys olivaceus on the east coast of China through a combination of virus isolation, real-time reverse transcription polymerase chain reaction (RT-PCR) and conventional RT-PCR followed by sequencing. Analysis using MEGA11 software revealed that the isolated VHSV belongs to genotype IVa. Bastard halibut fry were experimentally infected by immersion and gill inoculation with infected cell culture medium and exhibited clinical signs. Cytopathic effects (CPE) were observed again when the epithelioma papulosum cyprini (EPC) cells were inoculated with homogenized tissue samples from the diseased fish. Real-time RT-PCR confirmed the existence of the virus in the infected fish tissues. Transmission electron microscopy (TEM) revealed the presence of numerous virus particles in the infected EPC cells, both extracellularly and intracellularly. The combination of clinical signs, typical CPE, and genetic analysis identified the isolated virus as VHSV.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"161 ","pages":"69-74"},"PeriodicalIF":1.1,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143467084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the impact of the widely introduced Pacific oyster Magallana gigas on the dispersal of Bonamia (Haplosporida): a global snapshot.","authors":"Kristina M Hill-Spanik, Hannah Rothkopf, Allan E Strand, Ryan B Carnegie, James T Carlton, Lucia Couceiro, Jeffrey A Crooks, Hikaru Endo, Masakazu Hori, Mitsunobu Kamiya, Gen Kanaya, Judith Kochmann, Kun-Seop Lee, Lauren Lees, Masahiro Nakaoka, Eric Pante, Jennifer L Ruesink, Evangelina Schwindt, Åsa Strand, Richard Taylor, Ryuta Terada, Martin Thiel, Takefumi Yorisue, Danielle Zacherl, Erik E Sotka","doi":"10.3354/dao03834","DOIUrl":"https://doi.org/10.3354/dao03834","url":null,"abstract":"<p><p>Bonamia (Haplosporida) are oyster parasites capable of devastating oyster populations. The near-circumglobal distribution of the host generalist B. exitiosa has previously been associated with the natural and anthropogenic dispersal of broadly distributed non-commercial oysters in the Ostrea stentina species complex. Here, we took a global snapshot approach to explore the role of the widely introduced Pacific oyster Magallana gigas, a commercially important species that can be found on every continent except Antarctica, in transporting Bonamia. We screened 938 M. gigas individuals from 41 populations in this oyster's native and non-native geographic range for presence of Bonamia DNA using PCR. B. exitiosa was the only species detected and only within 2 of 5 populations from southern California, USA (10 and 42% PCR prevalence). Therefore, M. gigas could have played a role in transporting B. exitiosa to California (if introduced) and/or maintaining B. exitiosa populations within California, but morphological confirmation of infection needs to be done to better understand the host-parasite dynamics within this system. We detected no Bonamia DNA within any other non-native M. gigas populations (n = 302) nor within native M. gigas populations in Japan and Korea (n = 582) and thus found no evidence to support the co-dispersal of M. gigas and other Bonamia species. Lower sample sizes within some populations and the non-systematic nature of our sampling design may have led to false negatives, especially in areas where Bonamia are known to occur. Nevertheless, this global snapshot provides preliminary guidance for managing both natural and farmed oyster populations.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"161 ","pages":"39-46"},"PeriodicalIF":1.1,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143254309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First report of ictavirus acipenseridallo2 (AciHV-2) in Danube sturgeons Acipenser gueldenstaedtii in Austria.","authors":"Hella Schwegler, Laurent Bigarré, Karoline Lipnik, Nora Dinhopl, Astrid Holzer, Eva Lewisch","doi":"10.3354/dao03837","DOIUrl":"https://doi.org/10.3354/dao03837","url":null,"abstract":"<p><p>Newly stocked Danube sturgeons Acipenser gueldenstaedtii developed cutaneous lesions and nearly 100% mortality over the course of 2 mo after introduction into an Austrian fish farm. Necropsy revealed cutaneous plaques and hemorrhages, and histological findings in skin, gills, spleen and kidney tissues showed cell-nucleus alterations consistent with infection by a herpesvirus. The presence of a herpesvirus was demonstrated by the visualization of numerous typical viral particles in different tissues by electron microscopy. A newly developed conventional PCR protocol, targeting a fragment of the viral DNA polymerase gene, further confirmed the presence of a virus related to the species Ictavirus acipenseridallo2 (formerly Acipenserid herpesvirus-2; AciHV-2) in the diseased fish. Amplification products were sequenced and showed 100% identity to the Siberian sturgeon herpesvirus (SbSHV) strain. This is the first report of herpesvirus detection in sturgeon in Austria and of SbSHV, a strain of AciHV-2, in Danube sturgeons.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"161 ","pages":"47-53"},"PeriodicalIF":1.1,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143254421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Infection with Vibrio aestuarianus limits the utility of increasing resistance of Pacific oyster Crassostrea (Magallana) gigas against OsHV-1 µVar.","authors":"Asunción Cao, Marie-Agnès Travers, Tania Varela, Antonio Villalba","doi":"10.3354/dao03838","DOIUrl":"https://doi.org/10.3354/dao03838","url":null,"abstract":"<p><p>Infection with the oyster herpesvirus type 1 microvariant (OsHV-1 μVar) has caused mass mortalities of Pacific oyster larvae and spat in multiple countries. Selective breeding to enhance resilience against that virus had been shown as a promising defence strategy. Mass spat mortalities associated with OsHV-1 μVar affected Pacific oyster farms in Ría de Arousa (Galicia, NW Spain), which led us to explore the potential utility of selective breeding to increase cultured oyster survival. Thus, adult oysters that had survived through culture in that area, heavily affected by OsHV-1 μVar, and oysters collected from a naturalised oyster bed that had never been affected, were used as broodstocks in hatchery facilities to produce spat families from each origin. Spat families derived from each stock were transferred into a culture raft in Ría de Arousa; survival and occurrence of OsHV-1 μVar were monitored through cultivation. Spat mortality associated with OsHV-1 μVar was higher in the families deriving from the naïve stock. Adult oyster mortality was detected close to the end of growing-out, which was not associated with OsHV-1 μVar but putatively caused by Vibrio aestuarianus infection. Adult mortality was higher in the families with the highest V. aestuarianus loads; notably, the oyster families with the lowest spat mortality showed the highest adult mortality. Therefore, a potential increase of spat survival in Ría de Arousa through selective breeding to enhance oyster resilience against OsHV-1 μVar could be counteracted by high adult mortality associated with V. aestuarianus infection.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"161 ","pages":"55-67"},"PeriodicalIF":1.1,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143254632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}