Journal of fish diseases最新文献

{"title":"Diploid and triploid Chinook salmon (Oncorhynchus tshawytscha) exhibit differential immunological responses to acute thermal stress","authors":"Noah P. Rogozynski,&nbsp;Ivan G. Cadonic,&nbsp;Manuel Soto-Dávila,&nbsp;Valentina Wong-Benito,&nbsp;Tania Rodriguez-Ramos,&nbsp;Paul Craig,&nbsp;Brian Dixon","doi":"10.1111/jfd.13998","DOIUrl":"10.1111/jfd.13998","url":null,"abstract":"<p>Exposure to temperatures outside of a fish's optimal range results in suppression of the immune system, ultimately leaving aquaculture stocks susceptible to disease outbreaks. This effect is exacerbated in triploid fishes, which demonstrate greater susceptibility to stress than their diploid counterparts. This study investigates the impacts of acute heat stress on the abundance of immune transcripts and proteins in diploid and triploid Chinook salmon (<i>Oncorhynchus tshawytscha</i><b>)</b>, an important finfish crop. This study also demonstrates that acute heat stress induces significant increases in the abundance <i>hsp70</i>, <i>hsp90</i> and <i>il1b</i> transcripts in the head kidneys, gills and heart ventricles of both diploid and triploid Chinook salmon. Widespread dysregulation of antigen-presentation transcripts was also observed in fish of both ploidies. These results suggest that acute heat stress activates acute-phase responses in Chinook salmon and dysregulates antigen presentation, potentially leaving fish more susceptible to infection. At the protein level, IL-1β was differentially expressed in the head kidney and ventricles of diploid and triploid salmon following heat shock. Differential expression of two tapasin-like proteins in diploid and triploid salmon subjected to heat shock was also observed. Altogether, these data indicate that diploid and triploid Chinook salmon respond differently to acute thermal stressors.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jfd.13998","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141600200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Immersion immunization with recombinant Saccharomyces cerevisiae displaying ORF25 induced protective immunity against cyprinid herpesvirus 2","authors":"Maoxia Yang,&nbsp;Sheng Luo,&nbsp;Qianjin Zhou,&nbsp;Jianfei Lu,&nbsp;Jiong Chen","doi":"10.1111/jfd.13996","DOIUrl":"10.1111/jfd.13996","url":null,"abstract":"<p>Displaying antigens on yeast surface as an oral vaccine has been widely explored, while its potential as an immersion vaccine has not been evaluated. Here, an immersion vaccine was prepared by displaying ORF25 of Cyprinid herpesvirus 2 (CyHV-2) on the surface of <i>Saccharomyces cerevisiae</i>. <i>Carassius auratus gibelio</i> was immersion immunized by 2 × 10⁷ CFU/mL yeast for 2 h, and reinforce the immunity using the same method 14 days after the first immunization. The results showed that ORF25 specific antibody in immunized crucian carp serum was detected at a high level, and the mRNA expression level of <i>IgM</i>, <i>IgT</i>, <i>IL-1β</i>, and <i>IFN-1</i> in vaccinated head-kidney and spleen tissues were higher than the control group, indicating that innate and adaptive immunity were induced. Moreover, the immersion vaccination provided effective protection for fish against CyHV-2, leading to a relative percent survival of 50.2%. Meanwhile, immersion vaccination restrained virus replication and histological damage in CyHV-2 infected crucian carp. Our data suggested that immersion immunization of <i>S. cerevisiae</i>-displayed ORF25 could be served as a candidate vaccine to prevent CyHV-2 infection.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141554952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lactococcus lactis MA5 is a potential autochthonous probiotic for nutrient digestibility enhancement and bacterial pathogen inhibition in hybrid catfish (Ictalurus punctatus × I. furcatus)","authors":"Jing Huang,&nbsp;Heather R. Jordan,&nbsp;Caitlin E. Older,&nbsp;Matt J. Griffin,&nbsp;Peter J. Allen,&nbsp;David J. Wise,&nbsp;Penelope M. Goodman,&nbsp;J. Grant Reifers,&nbsp;Fernando Y. Yamamoto","doi":"10.1111/jfd.13997","DOIUrl":"10.1111/jfd.13997","url":null,"abstract":"<p>With the emergence of diseases, the U.S. catfish industry is under challenge. Current trends prefer autochthonous bacteria as potential probiotic candidates owing to their adaptability and capacity to effectively colonize the host's intestine, which can enhance production performance and bolster disease resistance. The objective of this study was to isolate an autochthonous bacterium as probiotic for hybrid catfish. Initially, an analysis of the intestinal microbiota of hybrid catfish reared in earthen ponds was conducted for subsequent probiotic development. Twenty lactic acid bacteria were isolated from the digesta of overperforming catfish, and most of the candidates demonstrated probiotic traits, including proteolytic and lipolytic abilities; antagonistic inhibition of catfish enteric bacterial pathogens, negative haemolytic activity and antibiotic susceptibility. Subsequent to this screening process, an isolate of <i>Lactococcus lactis</i> (MA5) was deemed the most promising probiotic candidate. In silico analyses were conducted, and several potential probiotic functions were predicted, including essential amino acids and vitamin synthesis. Moreover, genes for three bacteriocins, lactococcin A, enterolysin A and sactipeptide BmbF, were identified. Lastly, various protectant media for lyophilization of MA5 were assessed. These findings suggest that <i>Lactococcus lactis</i> MA5 can be an autochthonous probiotic from hybrid catfish, holding promise to be further tested in feeding trials.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141554953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mass mortality event of round sardinella Sardinella aurita Valenciennes associated with Glugea Thélohan, 1891 microsporidian infection off the southern Italian coast","authors":"Alejandro López-Verdejo,&nbsp;Flavia Occhibove,&nbsp;Barbara degli Uberti,&nbsp;Francisco E. Montero,&nbsp;Mario Santoro","doi":"10.1111/jfd.13995","DOIUrl":"10.1111/jfd.13995","url":null,"abstract":"<p>Intracellular parasites of the genus <i>Glugea</i> Thélohan, 1891 (Microsporidia) comprise about 34 putative species capable of causing high morbidity and mortality in freshwater and marine teleost fishes. In this study, we report on the first mass mortality event associated with <i>Glugea</i> sp. infecting free-ranging round sardinella <i>Sardinella aurita</i> in the southern Tyrrhenian Sea (Italy). Here, we describe the ultrastructure of mature spores of this microsporidian and characterize it molecularly, as well as report its phylogenetic position. Most of the affected fish showed an irregular swelling of its abdomen. At necropsy, a variable number of xenomas, spherical to ellipsoidal in shape, were found in the peritoneal cavity strongly attached to the viscera of all fish. Histological analysis revealed varying severity of chronic inflammation along with occasional necrosis in visceral organs associated with multiple xenoma proliferation. These pathological findings were considered the main cause of this mass mortality event. Morphologically, the present material was closely related to <i>G. sardinellesis</i> and <i>G. thunni</i>. The phylogenetically closest taxa to the newly SSU rDNA sequence were <i>G. thunni</i> and an erroneusly identified  <i>G. plecoglossi</i>, which were very closely related to each other, also suggesting that all these sequences might belong to the same species.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141476735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mullus barbatus L. and Mullus surmuletus L. from western Mediterranean waters (SE Spain) are infected by Hysterothylacium fabri, but not by zoonotic nematodes. Possible impact on fish hosts#","authors":"Manuel Morales-Yuste,&nbsp;Jesús López-Valverde,&nbsp;Natalia Sánchez-Fernández,&nbsp;Jesús Veiga,&nbsp;Mario Garrido,&nbsp;Francisco Javier Adroher,&nbsp;Rocío Benítez","doi":"10.1111/jfd.13989","DOIUrl":"10.1111/jfd.13989","url":null,"abstract":"<p>In order to know whether there is a risk of anisakiasis (or anisakidosis) by consumption of fish of the genus <i>Mullus</i> from the western Mediterranean Sea, which are appreciated for their quality, an epidemiological survey was carried out to evaluate the occurrence of zoonotic or potentially zoonotic nematodes in <i>M. barbatus</i> and <i>M. surmuletus</i>. Although the presence of the third larval stage (L3) of anisakids (<i>Anisakis</i> and <i>Contracaecum</i>) has been previously described in these fish, the results showed the absence of anisakids and the presence, never in muscle, of L3 and L4 of raphidascaridids of the genus <i>Hysterothylacium</i>, molecularly identified as <i>H. fabri</i>. Phylogenetic analysis groups them into the Mediterranean Sea clade, far from individuals isolated in the Pacific Ocean. Prevalence was slightly higher, but not significant, in <i>M. barbatus</i> versus <i>M. surmuletus</i> (72.3% vs 60.0%), but mean intensity (MI) and mean abundance (MA) parameters were approximately twice as high in <i>M. barbatus</i> as in <i>M. surmuletus</i> (MI 5.8 vs 2.8, <i>p</i> = .001; MA 4.2 vs 1.7, <i>p</i> &lt; .001). The presence of the parasite seems to have different effects on these two sympatric species. In <i>M. barbatus</i> it seems to affect their growth, as it appreciably reduces the value of allometry coefficient in infected fish (2.78 vs. 2.18). On the other hand, in <i>M. surmuletus</i> the infection significantly (<i>p</i> &lt; .04) affects the Fulton's condition factor, an indicator of the health status of the fish. It can be concluded that the ingestion of these fish by the people poses negligible risk of anisakiasis, but the consumer should continue to be urged to follow the rules of prevention against this illness.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jfd.13989","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141492275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Changes in blood serum parameters in farmed rainbow trout (Oncorhynchus mykiss) during a piscine lactococcosis outbreak","authors":"Giuseppe Esposito,&nbsp;Stefania Bergagna,&nbsp;Silvia Colussi,&nbsp;Khalid Shahin,&nbsp;Roberta Rosa,&nbsp;Donatella Volpatti,&nbsp;Caterina Faggio,&nbsp;Camilla Mossotto,&nbsp;Alice Gabetti,&nbsp;Alessandra Maganza,&nbsp;Elena Bozzetta,&nbsp;Marino Prearo,&nbsp;Paolo Pastorino","doi":"10.1111/jfd.13994","DOIUrl":"10.1111/jfd.13994","url":null,"abstract":"<p>The aquaculture sector plays a vital role in global food security, yet it grapples with significant challenges posed by infectious diseases. Piscine lactococcosis is one of the significant threats in rainbow trout aquaculture due to its potential to cause severe economic losses through mortalities, reduced growth rates, and increased susceptibility to other pathogens. It poses challenges in disease management strategies, impacting the sustainability and profitability of rainbow trout farming. The current study focuses on the variations in serum blood parameters of farmed rainbow trout <i>Oncorhynchus mykiss</i> during a lactococcosis outbreak caused by <i>Lactococcus garvieae</i>. Blood samples were collected for biochemical analysis, fish were examined for parasites and bacteria, and DNA from bacterial colonies was PCR-amplified and sequenced for identification. Overall, 13 biochemical parameters, including proteins, enzymes, lipids, chemicals, and minerals, were measured in serum blood samples from both diseased and healthy fish. The results indicate significant alterations in the levels of these parameters during the outbreak, highlighting the impact of infections on the blood profile of farmed rainbow trout. Urea levels were significantly higher in diseased fish compared to controls, and creatinine, phosphorus, and magnesium also showed similar trends. Alanine aminotransferase and total protein levels were higher in control fish. Chloride levels differed significantly between groups. Iron levels were higher in controls and lower in diseased fish. No significant differences were found in other parameters. This study reveals significant changes in serum blood parameters of rainbow trout during a lactococcosis outbreak caused by <i>L. garvieae</i>. These changes highlight the potential of these parameters as tools for monitoring health status, stress, and aquaculture management. Continuous monitoring can provide valuable insights into disease severity and overall fish health, aiding in the development of improved management practices. The presented data contribute to understanding the pathophysiology of piscine lactococcosis and developing effective mitigation strategies for farmed rainbow trout.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jfd.13994","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141476733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic pathology and pathogen distribution of the yeast Metschnikowia bicuspidata in the Chinese mitten crab (Eriocheir sinensis)","authors":"Xinran Shi,&nbsp;Na Sun,&nbsp;Jiannan Liu,&nbsp;Senting Pu,&nbsp;Zhouling Chen,&nbsp;Dong Sheng,&nbsp;Kexin Hao,&nbsp;Xiaodong Li,&nbsp;Shigen Ye","doi":"10.1111/jfd.13993","DOIUrl":"10.1111/jfd.13993","url":null,"abstract":"<p>In this study, the “milky disease” model of <i>Eriocheir sinhensis</i> was constructed via intramuscular injection with the pathogenic yeast <i>Metschnikowia bicuspidata</i>. The dynamic pathological changes of <i>E. sinensis</i> after injection were elucidated with two staining methods (haemotoxylin-eosin and alcian blue periodic acid-Schiff) and fluorescence in situ hybridization technology. Anatomical observation revealed three stages of the “milky disease”: no clinical signs (1–4 days after infection), the appearance of signs of disease (5–7 days), and significant liquefaction (10 days). Histological observation also revealed three stages of the disease: yeast diffusion (1–2 days after infection), yeast slow development (3–4 days), and yeast rapid proliferation (5 days). And FISH technique was suitable for the early detection of infection with <i>M. bicuspidata</i> in <i>E. sinensis</i>. We found that <i>M. bicuspidata</i> spread to the whole body of the crab through the haemolymph and developed into fungal septicaemia. These results elucidate the systemic pathological characteristics of “milky disease” in <i>E. sinensis</i> and suggest the pathogenic mechanism of <i>M. bicuspidata</i>.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141476734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proteomic characterization of Tenacibaculum dicentrarchi under iron limitation reveals an upregulation of proteins related to iron oxidation and reduction metabolism, iron uptake systems and gliding motility","authors":"Ruben Avendaño-Herrera,&nbsp;Macarena Echeverría-Bugueño,&nbsp;Mauricio Hernández,&nbsp;Pablo Saldivia,&nbsp;Rute Irgang","doi":"10.1111/jfd.13984","DOIUrl":"10.1111/jfd.13984","url":null,"abstract":"<p>A strategy for vaccine design involves identifying proteins that could be involved in pathogen–host interactions. The aim of this proteomic study was to determine how iron limitation affects the protein expression of <i>Tenacibaculum dicentrarchi</i>, with a primary focus on virulence factors and proteins associated with iron uptake. The proteomic analysis was carried out using two strains of <i>T. dicentrarchi</i> grown under normal (control) and iron-limited conditions, mimicking the host environment. Our findings revealed differences in the proteins expressed by the type strain CECT 7612^T and the Chilean strain TdCh05 of <i>T. dicentrarchi</i>. Nonetheless, both share a common response to iron deprivation, with an increased expression of proteins associated with iron oxidation and reduction metabolism (e.g., SufA, YpmQ, SufD), siderophore transport (e.g., ExbD, TonB-dependent receptor, HbpA), heme compound biosynthesis, and iron transporters under iron limitation. Proteins involved in gliding motility, such as GldL and SprE, were also upregulated in both strains. A negative differential regulation of metabolic proteins, particularly those associated with amino acid biosynthesis, was observed under iron limitation, reflecting the impact of iron availability on bacterial metabolism. Additionally, the TdCh05 strain exhibited unique proteins associated with gliding motility machinery and phage infection control compared to the type strain. These groups of proteins have been identified as virulence factors within the <i>Flavobacteriaceae</i> family, including the genus <i>Tenacibaculum</i>. These results build upon our previous report on iron acquisition mechanisms and could lay the groundwork for future studies aimed at elucidating the role of some of the described proteins in the infectious process of tenacibaculosis, as well as in the development of potential vaccines.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141468513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deciphering the pathogenesis of melanized focal changes in the white skeletal muscle of farmed Atlantic salmon (Salmo salar)","authors":"Håvard Bjørgen,&nbsp;Malin Brimsholm,&nbsp;Charlotte Finstad Asserson,&nbsp;Kirstin Skaar,&nbsp;Geir Magne Knutsen,&nbsp;Øyvind Oaland,&nbsp;Randi Haldorsen,&nbsp;Per Gunnar Fjelldal,&nbsp;Tom Hansen,&nbsp;Espen Rimstad,&nbsp;Britta Andrea Kleist,&nbsp;Marius Lund-Iversen,&nbsp;Mariusz Pawel Kowalewski,&nbsp;Erling Olaf Koppang","doi":"10.1111/jfd.13988","DOIUrl":"10.1111/jfd.13988","url":null,"abstract":"<p>Melanized focal changes (MFCs) in the fillet of farmed Atlantic salmon is a major quality concern. The changes are thought to initially appear as acute red focal changes (RFCs) that progress into chronic MFCs. Recent findings have indicated that hypoxia may be important in their development, possibly leading to necrosis affecting not only myocytes but also adipocytes. Thus, the aim of this study was to investigate possible hypoxic conditions in RFCs and the subsequent inflammatory responses and lesions in the adipose tissue in RFCs and MFCs. A collection of RFCs, MFCs and control muscle samples from several groups of farmed salmon was studied. Using immunohistochemistry, we found induction of the hypoxia-inducible factor 1 pathway in RFCs. Histological investigations of RFCs and MFCs revealed different stages of fat necrosis, including necrotic adipocytes, a myospherulosis-like reaction and the formation of pseudocystic spaces. Accumulations of foamy macrophages were detected in MFCs, indicating degradation and phagocytosis of lipids. Using in situ hybridization, we showed the presence of tyrosinase- and tyrosinase-related protein-1-expressing amelanotic cells in RFCs, which in turn became melanized in MFCs. In conclusion, we propose a sequence of events leading to the formation of MFCs, highlighting the pivotal role of adiposity, hypoxia and fat necrosis.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jfd.13988","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141468510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the use of fatty acid ethyl esters as a potential natural solution for the treatment of fish parasitic diseases","authors":"Arunjyothi Jawaji,&nbsp;Inna Khozin Goldberg,&nbsp;Dina Zilberg","doi":"10.1111/jfd.13991","DOIUrl":"10.1111/jfd.13991","url":null,"abstract":"<p>Alternatives to conventional chemical treatments for parasitic diseases in fish are needed. Microalgal-sourced fatty acid ethyl esters (FAEEs) have shown an antiparasitic effect against <i>Gyrodactylus turnbulli</i> infection in guppies. Here, we tested a range of commercial FAEEs of various carbon chain lengths and unsaturation levels against two fish parasites. Guppies and barramundi infected with <i>G. turnbulli</i> and <i>Trichodina</i> sp., respectively, were used. The most effective FAEE, after excluding those toxic to fish, was ethyl laurate (12:0). For both parasites, the LD50 was 18.75 μM within 250 min of incubation. Ethyl eicosapentaenoate (20:5<i>n</i>3) was the next most effective FAEE against <i>G. turnbulli</i>, and dihomo-γ-linolenic acid ethyl ester (20:3<i>n</i>6) and ethyl α-linolenate (18:3<i>n</i>3) were the next most effective against <i>Trichodina</i> sp. In addition, FAEEs prepared from the microalga <i>Phaeodactylum tricornutum</i> residue, after fucoxanthin extraction, were examined against <i>Trichodina</i> sp. infection in barramundi for the first time. LD85 and LD100 was achieved at 2.5 and 5 μL mL⁻¹ of the FAEE preparation, respectively. In vivo, immersion of infected barramundi in 1.25 μL mL⁻¹ of this preparation for 24 h reduced infection prevalence from 100% to 53% and was non-toxic to fish.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jfd.13991","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141468511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}