Journal of aquatic animal health最新文献

{"title":"Low thiamine concentrations are associated with altered cardiac morphology across reproductive life histories of spawning Chinook Salmon.","authors":"K A Adeli, T E Pitcher, J M Ludwig, J Rinchard, B D Neff","doi":"10.1093/jahafs/vsaf007","DOIUrl":"https://doi.org/10.1093/jahafs/vsaf007","url":null,"abstract":"<p><strong>Objective: </strong>Thiamine deficiency is a widespread issue in salmonine species and has been reported to induce changes in cardiac morphology and cardiac dysfunction in Lake Trout Salvelinus namaycush. Here, we assess the effects of thiamine concentration on the ventricular morphology of three reproductive life histories (jack males, hooknose males, and females) of wild spawning Chinook Salmon Oncorhynchus tshawytscha.</p><p><strong>Methods: </strong>Fish were sampled from the Credit River (a Lake Ontario tributary), and skeletal muscle, ventricle, and liver thiamine concentrations were quantified using high-performance liquid chromatography. A subset of ventricles was retained for histological analyses. Hematoxylin and eosin-stained slides were used to measure cardiomyocyte width and compact myocardium thickness, and Masson's trichrome-stained slides were used to measure levels of cardiac fibrosis. Level of spawning senescence was quantified based on a qualitative score.</p><p><strong>Results: </strong>Thiamine levels did not differ significantly among life histories, except that hooknose males had significantly greater skeletal muscle thiamine concentrations than females. Thiamine concentrations in skeletal muscle and the ventricle were positively correlated. Across all life histories, lower concentrations of thiamine in skeletal muscle were associated with increased levels of cardiomyocyte hypertrophy and cardiac fibrosis, independent of their relationships with ventricle mass and level of spawning senescence. No significant relationships were observed with compact myocardium thickness.</p><p><strong>Conclusions: </strong>Low thiamine concentrations are associated with pathological alterations in cardiac morphology across reproductive life histories in spawning Chinook Salmon.</p>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144159245","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":"Influence of tulsi Ocimum sanctum extract on fish health: Growth, hematology, serum immune parameters, and antioxidant status in Common Carp.","authors":"Syed Sikandar Habib, Saima Majeed, Khalid Hussain Rind, Saira Naz, Ümit Acar, Cristina Cravana, Mujeeb Ullah, Khalid Khan, Muhammad Zahid, Mohamed Mohany, Francesco Fazio","doi":"10.1093/jahafs/vsaf006","DOIUrl":"https://doi.org/10.1093/jahafs/vsaf006","url":null,"abstract":"<p><strong>Objective: </strong>In aquaculture, the trend is shifting towards using plant-derived alternatives that are abundant in phytochemicals as effective replacements for traditional antibiotics and synthetic feed additives. In the present study, the effects of tulsi Ocimum sanctum extract on growth performance, hemato-biochemical indices, serum immune parameters, and antioxidant parameters in Common Carp Cyprinus carpio were investigated.</p><p><strong>Methods: </strong>Common Carp (mean body weight ± SD = 10.6 ± 0.13 g) were fed experimental diets that contained tulsi leaf extract at 0.0 (control), 0.5, 1.0, and 1.5% for 60 d (25 fish/treatment).</p><p><strong>Results: </strong>The findings revealed a considerable enhancement in growth performance and a decreased feed conversion ratio, especially for the 1.0% tulsi-based diet. Additionally, weight gain and feed conversion ratio exhibited significance at both the linear and quadratic levels, as indicated by polynomial contrasts. The hematological and biochemical profiles exhibited improvements in groups receiving tulsi-enriched diets. The antioxidant status of fish serum exhibited a notable increase, as evidenced by elevated activities of total antioxidant capacity, superoxide dismutase, and catalase in fish that received the 1.0% and 1.5% tulsi-based diets. Tulsi-supplemented diets led to remarkable enhancements in serum lysozyme activity, alternative complement activity, and total immunoglobulin content. Moreover, tulsi supplementation at 1.0% and 1.5% showcased a significant reduction in serum glucose and cortisol levels compared to the other groups.</p><p><strong>Conclusions: </strong>In conclusion, tulsi extract emerged as a valuable asset, positively influencing growth, blood parameters, antioxidant balance, and serum immune response in Common Carp, particularly at supplementation levels ranging from 1.0% to 1.5% in the diet.</p>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144020227","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":"Edwardsiella ictaluri type III and type VI secretion system mutant strains as candidates for live attenuated vaccines.","authors":"Matthew L Rogge, Ahmad A Elkamel, Ronald L Thune","doi":"10.1093/jahafs/vsaf005","DOIUrl":"https://doi.org/10.1093/jahafs/vsaf005","url":null,"abstract":"<p><strong>Objective: </strong>Edwardsiella ictaluri, the causative agent of enteric septicemia of catfish, causes substantial economic losses to Channel Catfish Ictalurus punctatus producers in the United States. This study evaluates three E. ictaluri strains, each carrying a markerless deletion mutation in a type III or type VI secretion system gene, as candidates for a live attenuated vaccine against enteric septicemia of catfish in Channel Catfish. Replication in Channel Catfish cells, in vivo invasion and persistence, virulence, and the ability to provide single-dose protection against a wild-type E. ictaluri strain were evaluated for each mutant.</p><p><strong>Methods: </strong>In this study, three isogenic mutants were constructed that introduced deletions in esrC, eseG, and evpC. EsrC is a T3SS-encoded protein that regulates expression of multiple virulence genes, including the T3SS effector EseG and the T6SS structural protein EvpC. Each mutant strain was evaluated for its ability to replicate in Channel Catfish ovary cells and head-kidney-derived macrophage cells. Channel Catfish were also challenged with the mutant strains to evaluate if mutation affected invasion, colonization, or persistence within the head kidney, attenuated mortalities in Channel Catfish, or induced protection against disease following subsequent wild-type E. ictaluri exposure.</p><p><strong>Results: </strong>Each mutant maintained the ability to replicate within head-kidney-derived macrophage cells and Channel Catfish ovary cells, as well as invade and colonize the head kidney. Although able to replicate intracellularly and successfully colonize catfish tissue, all three mutants were significantly attenuated in their ability to persist in tissues and cause mortality. A single immersion in mutant strains 28 d prior to exposure to wild-type E. ictaluri resulted in significantly lower mortality than fish immersed in sterile broth, with relative percent survival ranging from 95% to 100%.</p><p><strong>Conclusions: </strong>The findings demonstrate the potential for the development of live attenuated E. ictaluri vaccine strains through the targeted mutation of one or more E. ictaluri T3SS and T6SS genes.</p>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144011542","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":"Psychoactive drug propranolol modulates behavioral, acetylcholinesterase, and oxidative stress parameters in freshwater African Sharptooth Catfish Clarias gariepinus.","authors":"Temitope Dadewura Melefa, Felix Atawal Andong, Funmilayo Faith Hinmikaiye, Edwin Ejike Ozota, Mary-Claret Nwoko, Venatius Chiamaka Steve Ubah, Gladys Ndidiamaka Ugwu, Christopher Didigwu Nwani","doi":"10.1093/jahafs/vsaf004","DOIUrl":"https://doi.org/10.1093/jahafs/vsaf004","url":null,"abstract":"<p><strong>Objective: </strong>Propranolol is a beta-blocker psychoactive drug used for the management of high blood pressure, tremors, atrial fibrillation, and migraine headaches. This study investigated the effect of propranolol on behavior, acetylcholinesterase, lipid peroxidation, superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase in the brain of African Sharptooth Catfish Clarias gariepinus juveniles.</p><p><strong>Methods: </strong>A total of 180 African Sharptooth Catfish were exposed to 7.00-, 9.00-, 11.00-, 13.00-, and 15.00-mg/L acute propranolol concentrations and a control (0.00 mg/L) for 24, 48, 72, and 96 h, and the 96-h LC50 value was 9.48 mg/L. For sublethal study, 120 juvenile African Sharptooth Catfish were divided into four groups of 30 fish each and exposed to 1.90-, 0.95-, and 0.47-mg/L propranolol concentrations and a control for 21 d and allowed to recover for 7 d. All the treatment groups and control were set in triplicates, with 10 fish in each. The behavioral changes due to propranolol exposure were monitored by direct observation and scoring during the exposure and withdrawal period. The brains of fish were sampled every week for 4 weeks in order to evaluate the effects of propranolol on acetylcholinesterase, lipid peroxidation, and oxidative stress parameters.</p><p><strong>Results: </strong>Behavioral changes were evidenced by alterations in swimming rates, air gulping activities, and opercula beats in the propranolol-exposed fish during the acute exposure. Sublethal exposure resulted in a significant decrease in superoxide dismutase and catalase but increase in glutathione peroxidase and reductase values. Significant increase in lipid peroxidation and acetylcholinesterase enzyme levels were observed as exposure duration increased from day 7 compared with the control. The effects of propranolol on the observed parameters appeared to wane after fish withdrawal from the drug for 7 d.</p><p><strong>Conclusions: </strong>The drug propranolol, as demonstrated by these alterations, may negatively impact nontarget aquatic species and may have ecological consequences.</p>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143993179","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":"Identical sequence types of Yersinia ruckeri associated with lethal disease in wild-caught invasive Blue Catfish and cultured hybrid catfish (Channel Catfish ♀ × Blue Catfish ♂) from disparate aquatic ecosystems.","authors":"Christine L Densmore, Madeleine Hendrix, Stephen R Reichley, Clayton D Raines, Noah R Bressman, Zachary S Crum, Lester H Khoo, Geoffrey C Waldbieser, Matt J Griffin, Timothy J Welch, Luke R Iwanowicz","doi":"10.1093/jahafs/vsae004","DOIUrl":"10.1093/jahafs/vsae004","url":null,"abstract":"<p><strong>Objective: </strong>The Blue Catfish Ictalurus furcatus is commonly raised in warmwater aquaculture in the United States to produce Channel Catfish I. punctatus × Blue Catfish hybrids. It is also a prominent aquatic invasive species of concern in the mid-Atlantic region of the United States. Here, Yersina ruckeri was isolated from moribund Blue Catfish and hybrid catfish from disparate regions of the USA. The goal of the research here was to compare these Y. ruckeri strains to each other and other known strains for which adequate sequence data was available. In addition, we sought to determine if the strain from Blue Catfish was pathogenic to Rainbow Trout Oncorhynchus mykiss.</p><p><strong>Methods: </strong>Moribund hybrid catfish from culture ponds in Mississippi were processed for diagnostic evaluation in March 2016. In April 2022, a moribund Blue Catfish specimen was collected from a tributary of the Nanticoke River in Maryland. Bacterial isolates were identified and characterized using biochemical tests, antimicrobial sensitivity screening, serotyping, and complete or partial genome sequencing. Disease pathology was described via histology. The isolate from Blue Catfish was used in challenge experiments to determine if it was pathogenic to Rainbow Trout. Multilocus sequencing typing was conducted using the PubMLST database.</p><p><strong>Results: </strong>Biochemical testing was consistent with Y. ruckeri. A draft genome of the Y. ruckeri isolate was assembled based on Oxford Nanopore Technology sequencing and identified a single genomic replicon (3,791,418 bp) consistent in size to other Y. ruckeri genomes and a pLT plasmid (60, 933 bp). The challenge study demonstrated no significant virulence of this isolate for Rainbow Trout (Y. ruckeri). This isolate was most similar to other strains isolated from ictalurids. Notably, the gyrase B gene from this isolate was identical to that of archived strains isolated from moribund Mississippi hybrid catfish aquaculture during 2016 and these isolates share identical PubMLST sequence type profiles. Similarly, they shared a pLT plasmid that differed by only 6 bp. This plasmid has never been reported from trout isolates and appears to be unique to ictalurids.</p><p><strong>Conclusions: </strong>Analyses here provide preliminary genetic evidence that geographically distant (Maryland and Mississippi, USA) isolates of Y. ruckeri from ictalurids are genetically similar to each other and Y. ruckeri (strain SC09) that infects ictalurids in China. This strain is not a biothreat to Rainbow Trout at typical culture temperatures.</p>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":"21-33"},"PeriodicalIF":1.5,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143780195","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":"Identification and characterization of Vibrio anguillarum (GA strain) isolated from Obscure Pufferfish Takifugu obscurus.","authors":"Wei Gao, Wenji Huang, Ling Shao","doi":"10.1093/jahafs/vsae005","DOIUrl":"10.1093/jahafs/vsae005","url":null,"abstract":"<p><strong>Objective: </strong>Aquaculture has faced significant challenges due to the emergence of various pathogens affecting fish species. One such species, the Obscure Pufferfish Takifugu obscurus, has experienced high mortality rates due to an outbreak of disease on a fishery farm in Shanghai.</p><p><strong>Methods: </strong>The pathogen responsible for this outbreak was isolated and identified as Vibrio anguillarum (GA strain) using a combination of morphological, biochemical, and whole-genome single-nucleotide polymorphism-based phylogenetic analyses. Pathogenicity tests confirmed that the GA strain could cause disease in healthy Obscure Pufferfish, inducing overt hemorrhagic symptoms. Histopathological analysis was performed to assess whether tissue damage had occurred. Whole-genome sequencing revealed that the GA strain possessed 235 virulence genes and two drug resistance-related genes: cyclic AMP receptor protein (CRP) and regulator of secondary metabolites A (rsmA). Testing via PCR further confirmed the presence of 10 common virulence genes.</p><p><strong>Results: </strong>Antibiotic susceptibility testing showed that the GA strain was highly sensitive to antibiotics such as tetracycline, doxycycline, minocycline, and compound sulfamethoxazole and was resistant to cefradine, cefazolin, penicillin, and vancomycin.</p><p><strong>Conclusions: </strong>To the best of our knowledge, this is the first study to report V. anguillarum as the pathogen responsible for this disease in Obscure Pufferfish. The isolate exhibited strong virulence and multidrug resistance. The findings lay the foundation for further disease control in Obscure Pufferfish and the investigation of the epidemiological mechanisms of V. anguillarum.</p>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":"34-46"},"PeriodicalIF":1.5,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143780201","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":"Pyrimidine analog effect on health and nutritional value of freshwater Stinging Catfish Heteropneustes fossilis.","authors":"Bulbul Ali, Pooja Pandey, Jyoti Pandey, Abha Mishra","doi":"10.1093/jahafs/vsae003","DOIUrl":"10.1093/jahafs/vsae003","url":null,"abstract":"<p><strong>Objective: </strong>Pyrimidine has a broad range of biological actions and may be an eco-friendly substitute for health management.</p><p><strong>Methods: </strong>To explore bioefficiency in fish, different concentrations (10 fg/mL to 1 mg/mL) of a pyrimidine analog (4,6-dimethyl-2-hydroxypyrimidine hydrochloride) were prepared from stock solution in water with Stinging Catfish Heteropneustes fossilis for 24 h to determine the effective concentration based on hematological parameters. The effective concentration of pyrimidine (10 pg/mL) was further examined for a study of duration effects (1, 5, and 21 d), followed by a 1-week recovery period (in only water).</p><p><strong>Results: </strong>The pyrimidine analog improved health-supportive hematological parameters and moderated antioxidative stress. Pyrimidine treatment significantly increased red blood cell count and hemoglobin in Stinging Catfish. It also significantly decreased the white blood cell count, myeloperoxidase activity, and nitroblue tetrazolium in a time-dependent manner, thus helping to manage stress. Nutrient levels (protein, carbohydrate, and lipid) also were improved in pyrimidine-treated fish compared to control fish without treatment.</p><p><strong>Conclusions: </strong>Results supported the stimulatory effect of pyrimidine on fish immunity, nutrient level, and health parameters. During the recovery period, the levels of the analyzed parameters remained close to those measured at 21 d of treatment compared to the control fish. A reduction in health-supportive parameters 1 week after pyrimidine treatment supported the metabolized nature of the pyrimidine analog compared to other contemporary bioaccumulative drugs. There was no side effect of the effective concentration of the pyrimidine analog, and it did not cause any change in body weight and growth after treatment.</p>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":"11-20"},"PeriodicalIF":1.5,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143780143","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":"Finding the pulse of healthy native freshwater mussels (order Unionida): Insights from propagation biologists.","authors":"Madison E Mueller, Catherine E LePrevost, W Gregory Cope","doi":"10.1093/jahafs/vsae001","DOIUrl":"10.1093/jahafs/vsae001","url":null,"abstract":"<p><strong>Objective: </strong>This study engaged representative native freshwater mussel propagation biologists in focus group discussions to learn their views and priorities related to the development and adoption of freshwater mussel health metrics. It provides a case study on how early consultation with practitioners can better inform research questions and improve imperiled species conservation.</p><p><strong>Methods: </strong>Two focus group discussions were conducted with freshwater mussel propagation biologists from across the United States to understand the needs of conducting mussel health assessments, current approaches, technical capacity, and where advances may be most beneficial.</p><p><strong>Results: </strong>Propagation biologists identified how they currently measure freshwater mussel health, listed the largest threats to health, explained similarities among approaches, and made recommendations for future research.</p><p><strong>Conclusions: </strong>Propagation biologists called for quantitative metrics that complement current procedures that could be measured nonlethally and were reflective of health and resilience rather than presence or absence of disease. Further conservation research could benefit from early engagement with propagation biologists to better ensure adoption of research products and tools.</p>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":"47-53"},"PeriodicalIF":1.5,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12087955/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143780166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Fingerling stocking size has no influence on proliferative gill disease severity in farm-raised Channel Catfish.","authors":"Bradley M Richardson, Noor Ul-Huda, Cynthia Ware, Alvin C Camus, Caitlin E Older, Fernando Y Yamamoto, Penelope M Goodman, J Grant Reifers, Charles M Walker, Justin M Stilwell, David P Marancik, David J Wise, Matt J Griffin","doi":"10.1093/jahafs/vsae002","DOIUrl":"10.1093/jahafs/vsae002","url":null,"abstract":"<p><strong>Objective: </strong>The myxozoan Henneguya ictaluri is the causative agent of proliferative gill disease (PGD) in Channel Catfish Ictalurus punctatus and hybrid catfish (Channel Catfish × Blue Catfish I. furcatus), which is a significant disease concern within the commercial catfish industry of the southeastern United States. Incidence of PGD occurs most frequently in fingerling-sized catfish when the fish are being transferred from nursery ponds to grow-out ponds. Mitigation strategies for PGD primarily involve the avoidance of stocking fish into ponds with existent lethal concentrations of the parasite, as determined through sentinel fish exposures or H. ictaluri-specific quantitative PCR. This study aimed to evaluate the potential of stocking larger fingerlings to improve survival and investigate the influence on three metrics of gill condition.</p><p><strong>Methods: </strong>Two sizes of Channel Catfish fingerlings (∼12 and ∼20 cm) were stocked into nylon-mesh net-pens located in 19 commercial ponds with varying levels of H. ictaluri activity. After 1 week, fish were removed from the ponds and mortality was recorded. All survivors were euthanized for gross, histological, and molecular assessment. Gill biopsies from surviving fish were evaluated to estimate gill damage based on the presence of chondrolytic lesions in gill clip wet mounts. The number of characteristic PGD lesions and the number of presporogonic stages present were assessed histologically.</p><p><strong>Results: </strong>Generalized linear regression showed no interaction between parasite burden in the pond water or gill tissues and fingerling size. In all regressions, only parasite concentrations in pond water or gill tissues were significant predictors of any gill condition metrics.</p><p><strong>Conclusions: </strong>This study suggests that stocking of larger fingerlings provides no appreciable protection from PGD mortality or sublethal gill damage. Though smaller fingerlings regularly showed slightly better average gill condition compared to larger fingerlings, this occurred primarily in ponds with the highest parasite concentrations, which were likely influenced by survival bias.</p>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":"1-10"},"PeriodicalIF":1.5,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12087954/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143780189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Predicting the abundance of Lepeophtheirus salmonis in the Bay of Fundy, New Brunswick","authors":"Marianne I. Parent,&nbsp;Henrik Stryhn,&nbsp;K. Larry Hammell,&nbsp;Mark D. Fast,&nbsp;Raphaël Vanderstichel","doi":"10.1002/aah.10235","DOIUrl":"10.1002/aah.10235","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>The primary objective was to construct a time series model for the abundance of the adult female (AF) sea lice <i>Lepeophtheirus salmonis</i> in Atlantic Salmon <i>Salmo salar</i> farms in the Bay of Fundy, New Brunswick, Canada, for the period 2016–2021 and to illustrate its short-term predictive capabilities.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Sea lice are routinely counted for monitoring purposes, and these data are recorded in the Fish-iTrends database. A multivariable autoregressive linear mixed-effects model (second-order autoregressive structure) was generated with the outcome of the abundance of AF sea lice and included treatments, infestation pressures (a measure that represents the dose of exposure of sea louse parasitic stages to potential fish hosts) within sites (internal) and among sites (external), and other predictors. The treatments were categorized by duration and type.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Result</h3>\u0000 \u0000 <p>The effect of mechanical treatments decreased with increasing sea surface temperature. In-sample predictions had good accuracy. A one-standard-deviation increase in the external infestation pressures (EIP_AF) produced a significant relative increase in the abundance of AF sea lice by 5% when other model predictors were kept constant. Sites separated by short seaway distances had stronger EIP_AF than sites with more considerable distances.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>This model may be helpful for managers and farmers in implementing sea lice mitigation strategies on salmon farms in the Bay of Fundy.</p>\u0000 </section>\u0000 </div>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":"36 4","pages":"355-373"},"PeriodicalIF":1.5,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11685058/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142909726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}