Journal of aquatic animal health最新文献

{"title":"Notable bacterial diversity isolated from naturally infected fish in an understudied region of Pakistan.","authors":"Muhammad Rauf, Shandana Ali, Richard Daniel, Noor Ul Akbar, Muhammad Adnan, Muhammad Qasim, Farman Ullah Dawar","doi":"10.1093/jahafs/vsag012","DOIUrl":"https://doi.org/10.1093/jahafs/vsag012","url":null,"abstract":"<p><strong>Objective: </strong>The aquaculture sector in Pakistan remains underdeveloped, as aquaculture has not yet received adequate attention. Studies focusing on the health status of fish in the natural water bodies within Pakistan are rare.</p><p><strong>Methods: </strong>This study isolated and characterized bacteria from naturally infected cyprinid species across Khyber Pakhtunkhwa province. In total, 56 bacterial species were identified from 100 different naturally infected freshwater fish samples, with both internal and external organs examined.</p><p><strong>Results: </strong>Molecular characterization showed that among the nine families characterized in total, the dominant families were Enterobacteriaceae and Aeromonadaceae, and the dominant species were Enterobacter spp., Aeromonas spp., Klebsiella spp., Symbiopectobacterium spp., and Citrobacter spp. This study also found bacterial species for the first time in Pakistan that are rarely reported in global aquaculture. These included Rahnella contaminans and species of Rahnella, Yokenella, and Morganella in the gills, liver, and muscle of Common Carp Cyprinus carpio, Rohu Labeo rohita, and Grass Carp Ctenopharyngodon idella. Additionally, human bacterial pathogens were also detected, which may indicate a potential health risk for fish consumers.</p><p><strong>Conclusions: </strong>Based on the level of bacterial infections observed, there is a critical need for continuous monitoring of fish populations to prevent potential disease outbreaks in aquaculture and thus avert economic losses.</p>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148759658","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":"Effects of probiotic dose on growth performance, health, and gut microbiota of Pacific white shrimp reared in biofloc conditions.","authors":"Ishini A Appuhami, Shrijan Bajracharya, D Allen Davis, Timothy J Bruce","doi":"10.1093/jahafs/vsag001","DOIUrl":"10.1093/jahafs/vsag001","url":null,"abstract":"<p><strong>Objective: </strong>This study evaluated the effect of commercial Bacillus spp. probiotics on growth performance, immunity, gut microbiota composition, and disease resistance to Vibrio parahaemolyticus in Pacific white shrimp Litopenaeus vannamei that were reared under biofloc conditions.</p><p><strong>Methods: </strong>A 56-d feeding trial was conducted in a static biofloc system with postlarval shrimp (1.00 ± 0.03 g). A total of 1,080 shrimp were randomly assigned to three groups: two treatment levels (recommended dose [PRO × 1] and a doubled dose [PRO × 2]) of a commercial probiotic blend, PRO4000X, alongside a control group (CTL; no probiotics). At the trial end point, hepatopancreas and gut samples were collected for gene expression. Gut samples were also obtained for gut microbiota analysis via 16S ribosomal RNA sequencing, and hemolymph samples were withdrawn to measure the total hemocyte count.</p><p><strong>Results: </strong>Probiotic applications did not significantly affect growth performance, including final biomass, mean weight, survival, and feed conversion ratio under the experimental conditions. The probiotic-treated shrimp exhibited enhanced survival during a V. parahaemolyticus (strain A3) challenge, with significantly lower mortality rates (P < 0.001; 42.5 ± 4.3% for PRO × 1 and 60 ± 6.5% for PRO × 2) relative to the CTL (100 ± 0.00%). Immune parameters, such as total hemocyte count, did not differ. Interestingly, the expression of the antioxidant gene sod (superoxide dismutase) in the shrimp gut was significantly downregulated in the PRO × 1 group relative to the control (P = 0.030), which suggests reduced oxidative stress under probiotic supplementation. The analysis of the gut microbiota revealed differences in alpha diversity, specifically in evenness and Shannon index, which were significantly higher in the PRO × 1 group. The analysis of the bacterial composition also revealed minor shifts in the dominant genera. Notably, Lysobacter was more abundant in the PRO × 1 group, which potentially reflects positive modulation of gut microbial communities in response to probiotic supplementation.</p><p><strong>Conclusions: </strong>Overall, the application of PRO4000X probiotics significantly reduced the V. parahaemolyticus infection in the shrimp that were reared in biofloc water and supported the regulation of immunity and microbial communities in the gut. These findings indicate that probiotics potentially help to improve shrimp health when shrimp are cultured in biofloc systems.</p>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":"57-72"},"PeriodicalIF":1.7,"publicationDate":"2026-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147838516","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":"Spontaneous ophthalmic lesions in laboratory-housed common cuttlefish Sepia officinalis and hummingbird bobtail squid Euprymna berryi.","authors":"Nadiah M H A van Eijk, Nina Vogt, Mark F Stidworthy, Emily Northrup, Andrew F Rich","doi":"10.1093/jahafs/vsag003","DOIUrl":"10.1093/jahafs/vsag003","url":null,"abstract":"<p><strong>Objectives: </strong>Given the limited ocular pathology data for common cuttlefish Sepia officinalis and hummingbird bobtail squid Euprymna berryi despite their high visual dependency, the purpose of this study was to investigate and describe the ophthalmic lesions in a cohort of laboratory-housed common cuttlefish and hummingbird bobtail squid.</p><p><strong>Methods: </strong>Cases were retrospectively selected from the International Zoo Veterinary Group Pathology database that reported confirmed clinical ophthalmic lesions or histopathological lesions. Twenty-five cases were identified that included clinical records and gross and histopathological examination of whole specimens. The cases included 19 common cuttlefish and six hummingbird bobtail squid, thus providing a sample of 50 eyes and orbital cavities.</p><p><strong>Results: </strong>Thirty-two of 50 individual eyes (64%) and 30 of 50 white bodies (60%) were affected. The most frequent lesion that was observed was inflammation (n = 29/32, 91%), primarily manifesting as uveitis (n = 23/32, 72%) and phakitis (n = 10/32, 31%). Cataracts were also common (n = 14/32, 44%), often with cataract-associated inflammation (n = 9/14, 64%). Leukopoietic hyperplasia of the white body was bilaterally observed in 15 of 25 animals (60%) and was thought to be associated with exophthalmos. In the absence of notable intraocular or infraorbital lesions in some animals, this change was considered reactive, likely in response to nonocular lesions, such as ulcerative dermatitis and branchitis. Notable additional findings included hypopyon-like lesions (n = 3/32, 9%), a single case of congenital ocular malformation, and one case with mesenchymal proliferations that were reminiscent of florid fibroplasia.</p><p><strong>Conclusions: </strong>This study contributes to the expanding knowledge of cephalopod ocular pathology, with previously unreported findings in these cephalopods including congenital ocular malformation and cases of -hypopyon-like lesions with proteinaceous material exudation and hemocytes in the anterior chamber. Additionally, it offers specific insights into the ocular pathology of the hummingbird bobtail squid.</p>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":"73-86"},"PeriodicalIF":1.7,"publicationDate":"2026-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148138336","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":"Effects of supplemental dietary blend of humic substances and butyric acid plus yeast cell walls on immunity and resistance to bacterial coinfection in juvenile Channel Catfish.","authors":"Abdulmalik A Oladipupo, Anita M Kelly, Benjamin R LaFrentz, D Allen Davis, Luke A Roy, Benjamin H Beck, Timothy J Bruce","doi":"10.1093/jahafs/vsag002","DOIUrl":"10.1093/jahafs/vsag002","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Objective: &lt;/strong&gt;The present study examined the effect of humic substance and butyric acid blend (HSB) supplementation, with and without yeast cell wall (YCW), on gut morphology, immunity, and resistance to Flavobacterium covae, Edwardsiella ictaluri, and their coinfection in juvenile Channel Catfish Ictalurus punctatus.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;A feeding trial was conducted in a recirculating aquaculture system with Channel Catfish fingerlings (19.7 ± 0.2 g). Thirty-seven Channel Catfish were randomly assigned into four dietary groups with supplemented feed (g/kg): HSB (2.0 HSB), YCW (0.5 YCW), HSB + YCW (1.0 HSB, 0.25 YCW), and a control group (not supplemented), each consisting of eight replicates. After 45 d of feeding the diets, growth performance was assessed and head kidney, spleen, and gill tissues were sampled for gene expression, while serum was collected for lysozyme activity. Subsequently, fish were pooled by treatment and challenged by immersion with either E. ictaluri (S97-773; 7.4 × 106 CFU/mL), F. covae (ALG-00-530; 1.2 × 106 CFU/mL), or coinfection with simultaneous half-doses of both bacteria.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;No significant differences were observed in fish growth performance and survival across treatments. However, Fulton's K-factor was significantly higher in the HSB group compared with the control. Serum lysozyme activity was significantly higher in the HSB group, while a numerically higher body mucus lysozyme activity was observed in the HSB + YCW group. No diet-related cytokine gene expression differences were observed in the kidney and splenic tissues. However, differences were observed in the expression of lysozyme genes lysc and lysg in the gill, with the highest expression in the YCW group. Furthermore, expression of ctsd (cellular protease) and defb (antimicrobial peptide) were different across all groups. Specifically, ctsd was upregulated in the HSB group when compared with the control. The expression of defb was upregulated in all treated groups, including HSB, YCW, and HSB + YCW, compared with the control group. After a 14-d bacterial challenge with either F. covae, E. ictaluri, or simultaneous exposure to both, significant differences in survival probabilities were observed across the treatment groups in the single E. ictaluri and coinfection groups but not in the F. covae group. Survival following E. ictaluri challenge varied among groups, with higher survival observed in the HSB group (79%) compared with the control fish (52%). Similarly, the HSB group showed improved survival (72%) compared with YCW (30%), HSB + YCW (45%), and the control group (30%) within the coinfected groups. Furthermore, the survival rate of Channel Catfish was lower in the coinfected groups than in those solely infected with E. ictaluri.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;Feeding Channel Catfish with a dietary humic substance and buryate blend reduced the susceptibility of Channel Catfish to E. ictalu","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":"37-56"},"PeriodicalIF":2.1,"publicationDate":"2026-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147486130","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":"Integration of histopathology and molecular tools in shrimp health surveillance: A case study from Colombia.","authors":"Jahnier A Caicedo Martínez, Gersson M Vásquez Machado, Claudia P Calderón Parra, Jennifer-Natalie Castro Vargas, Camilo E Rivera Palomino, Arun K Dhar","doi":"10.1093/jahafs/vsaf018","DOIUrl":"10.1093/jahafs/vsaf018","url":null,"abstract":"<p><strong>Objective: </strong>The present study assessed the added diagnostic value of histopathology in complementing molecular detection of World Organization for Animal Health-listed viral pathogens during Colombia's national shrimp health surveillance program.</p><p><strong>Methods: </strong>Pooled samples of pleopods from 1,470 whiteleg shrimp Penaeus vannamei (5 animals/pool for a total of 294 pooled samples) were screened for white spot syndrome virus, Taura syndrome virus, and yellow head virus using standardized PCR/reverse transcription PCR assays in accordance with Instituto Colombiano Agropecuario protocols. A subset of 81 shrimp was taken for whole-body histopathology analysis following standardized protocols and a semiquantitative G0-G4 lesion grading scale. Lesions were classified by organ system, and histopathological findings were compared to molecular results.</p><p><strong>Results: </strong>All PCR assays were negative, with internal and external controls performing as expected. Using histopathology, lesions were identified in 77% of the shrimp examined, and lesions were primarily mild. Frequent findings included integumentary and gill colonization by Zoothamnium spp.; hepatopancreatic tubular necrosis with hemocytic granuloma-like reactions compatible with bacterial infection; intranuclear inclusion-like bodies, possibly of parvoviral origin; and focal myofiber necrosis, with organisms consistent with microsporidia. Autolysis was common but did not preclude lesion interpretation.</p><p><strong>Conclusions: </strong>Histopathology provided diagnostic information that was not captured by targeted molecular assays, revealing subclinical, opportunistic, and nonviral processes relevant to shrimp health. Incorporating histopathology into routine surveillance programs enhances pathogen detection and strengthens health assessments to certify disease-free status of shrimp production systems, as recommended by the World Organization for Animal Health.</p>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":"1-10"},"PeriodicalIF":1.7,"publicationDate":"2026-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147443607","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":"Mercury concentrations, pathological, and biometrical findings in Smallmouth Bass from Great Smoky Mountains National Park.","authors":"Ashley N Morgan, Madison Callicott, Zachary Winston Clark, Augustin Clark Engman, Michelle M Dennis","doi":"10.1093/jahafs/vsaf016","DOIUrl":"10.1093/jahafs/vsaf016","url":null,"abstract":"<p><strong>Objective: </strong>The objective of this study was to evaluate the potential influence of skeletal muscle mercury (Hg) concentrations on the biometric parameters and the frequency of lesions in Smallmouth Bass Micropterus dolomieu that were captured from three streams in Great Smoky Mountains National Park. By investigating the correlations between lesions, parasitism, and Hg concentrations, this study details the potential sublethal Hg contamination in fish in protected stream ecosystems.</p><p><strong>Methods: </strong>Postmortem examinations with comprehensive histopathological analysis were performed on Smallmouth Bass (n = 62) that were collected from three streams in Great Smoky Mountains National Park, Abrams Creek (nAC = 27), Little River (nLR = 19), and Middle Prong Little Pigeon River (nMP = 16), from June to October 2022. Postmortem and histopathological data were matched to existing data on the concentrations of Hg in skeletal muscle to determine relationships between Hg concentration and pathology.</p><p><strong>Results: </strong>Smallmouth Bass from Abrams Creek had higher total Hg concentrations, higher proportions of gill lesions, lymphohistiocytic epicarditis, and increased percentages of splenic pigmented macrophage aggregates but lower proportions of myxozoan cysts relative to the fish from other streams. Smallmouth Bass with high concentrations of Hg exhibited increased total length and body mass and more frequently showed the presence of glycogen-like vacuolation and increased pigmented macrophage aggregates in kidney tissue. Myxozoan cysts were more common in fish with lower total Hg levels, signifying the possible role of environmental impacts on myxozoan infection pressure.</p><p><strong>Conclusions: </strong>These findings highlight the complex health profiles of Smallmouth Bass in a protected stream ecosystem, including high levels of Hg, parasitism, and lesions. Furthermore, this study underscores the importance of monitoring and mitigating heavy metal contaminants to safeguard wildlife health and recreational fishing resources.</p>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":"11-23"},"PeriodicalIF":2.1,"publicationDate":"2026-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146010534","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":"From parasite to pathology: A novel manifestation of cestodiasis in Octopus maya.","authors":"Linda Yacsiri Guadalupe Marmolejo-Guzmán, Eunice Danilú Couoh-Puga, Sheila Castellanos-Martínez, M Leopoldina Aguirre-Macedo","doi":"10.1093/jahafs/vsaf017","DOIUrl":"10.1093/jahafs/vsaf017","url":null,"abstract":"<p><strong>Objective: </strong>This study aimed to characterize the effects of Prochristianella sp. infection (Cestoda: Trypanorhyncha) in the Octopus maya, with focus on tissue pathology, immune response, and potential implications for host health.</p><p><strong>Methods: </strong>Molecular analyses of 28S ribosomal DNA were performed to confirm the identity of collected parasites from the buccal mass of octopus hosts. Macro- and microscopic observations of O. maya tissues, hemocyte counts, and histological analyses were conducted to assess the damage caused by the infection. Comparisons were made between naturally infected octopuses from Río Lagartos, Yucatán (the affected group), and minimally infected octopuses from Campeche (the control group) to establish a reference baseline for health and tissue morphology.</p><p><strong>Results: </strong>Prochristianella sp. 1 was the only parasitic species infecting the buccal mass of octopuses collected from Río Lagartos, contrasting with the absence of the parasite in octopuses from Campeche, which were used as a reference group to characterize the infection. The affected group exhibited an undescribed capsular structure on the superior mandibular muscle of the buccal mass, containing cestodes and mucus and associated with tissue alterations, such as fibrosis, hemocyte infiltration, and focal necrosis. These findings led to the provisional designation of this condition as \"myocestodiasis in cephalopods.\"</p><p><strong>Conclusions: </strong>This work provides new findings on helminth-induced pathologies, generating hypotheses about the underlying mechanisms in infected cephalopods. The study highlights the importance of multidisciplinary approaches to understanding host-parasite interactions. Furthermore, it lays the groundwork for managing and conserving the O. maya, an important marine resource of the Yucatán Peninsula.</p>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":"24-36"},"PeriodicalIF":1.7,"publicationDate":"2026-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145804353","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":"Does environmental enrichment mitigate parasite infection by reducing stress in Masu Salmon Oncorhynchus masou?","authors":"Yuhei Ogura, Koh Hasegawa","doi":"10.1093/jahafs/vsaf014","DOIUrl":"10.1093/jahafs/vsaf014","url":null,"abstract":"<p><strong>Objective: </strong>Captive animals are exposed to various stressors originating from their artificial environment. Although stress can initially be an adaptive physiological response, persistent stress generally decreases immune function and makes animals more susceptible to pathogens. Environmental enrichment is a strategy that has been widely used to mitigate excessive stress and enhance animal welfare, but the effectiveness of individual enrichment components remains controversial. Hence, this study aimed to reveal the effect of shelter enrichment on stress levels and parasite infections in Masu Salmon Oncorhynchus masou. By using a single component, the study will help to provide a better understanding of the underlying mechanism of the enrichment effect.</p><p><strong>Methods: </strong>We explored whether shelter-enriched conditions relieved stress in Masu Salmon by evaluating plasma cortisol levels. Fish provided with shelters were expected to experience less aggression from conspecifics and less stress from human disturbance. Moreover, we conducted a parasite challenge test using Ichthyobodo sp. to determine whether the presence of shelters inhibited infection by mitigating stress levels.</p><p><strong>Results: </strong>Fish in enriched tanks had significantly lower basal cortisol levels than those in control tanks, suggesting that they were less affected by stressors. Although the difference was not significant, fish in enriched tanks also tended to experience less infection by the parasites than fish in control tanks.</p><p><strong>Conclusions: </strong>Given these results, simple shelter enrichment appears to be an effective method for mitigating stress among captive fish and reducing stress intensity or frequency. In addition, shelter enrichment could be used to inhibit infectious diseases, although further work is needed to prove the effect. These findings confirm that shelter enrichment has measurable effects on the factors related to fish welfare, which should encourage the adoption of enrichment in fish farms.</p>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":"184-191"},"PeriodicalIF":1.7,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145225268","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 molecular identification, biological diversity, and infection features of myxozoan parasites in Whiting Merlangius merlangus along the Turkish coast of the Black Sea.","authors":"Cem Tolga Gürkanlı, Sevilay Okkay, Yılmaz Çiftçi, Ahmet Özer","doi":"10.1093/jahafs/vsaf010","DOIUrl":"10.1093/jahafs/vsaf010","url":null,"abstract":"<p><strong>Objective: </strong>Myxosporean parasites are worldwide-distributed cnidarians that infect the organs and tissues of marine and freshwater organisms, primarily fish. Based on morphological peculiarities, two myxosporean species, Myxidium gadi and Ceratomyxa merlangi, from the gallbladder content of Whiting Merlangius merlangus inhabiting four sampling localities (Kocaeli, Sinop, Ordu, and Trabzon) along the Black Sea coast of Türkiye have been identified.</p><p><strong>Methods: </strong>Concordant with the morphological data, the first phylogenetic analyses on the nucleotide sequences of 18S ribosomal DNA confirmed our Myxidium specimens to be M. gadi. This study also provided the first molecular data on C. merlangi, which appeared to be the closest species to C. cretensis and C. arcuata on the phylogenetic trees. The infection prevalence (%) and density values of each parasite species were calculated according to season and sampling localities of Whiting.</p><p><strong>Results: </strong>Ceratomyxa merlangi had a higher overall prevalence value (39.6%) than M. gadi (25.7%). The density values of both parasite species ranged between 2+ and 3+ in all fish samples. When the infection indices in sampling localities were compared for both parasite species, C. merlangi and M. gadi had the highest infection prevalence values in Sinop samples (66.3%); the highest density of infection (3+) was recorded in Sinop samples for C. merlangi and in Ordu samples for M. gadi.</p><p><strong>Conclusions: </strong>This study provides the first molecular data on M. gadi and C. merlangi, revealing their phylogenetic positions. In addition, seasonal and regional infection data for these species in the southern Black Sea region are reported for the first time, and it has been determined that both species can occur together.</p>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":"170-183"},"PeriodicalIF":1.7,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145225363","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":"Nonlethal detection of Renibacterium salmoninarum in Greenback Cutthroat Trout Oncorhynchus clarkii stomias comparing mucus, blood, and ovarian fluid samples to kidney tissues.","authors":"Tawni B R Firestone, Eric R Fetherman, Dana L Winkelman","doi":"10.1093/jahafs/vsaf013","DOIUrl":"10.1093/jahafs/vsaf013","url":null,"abstract":"<p><strong>Objective: </strong>Renibacterium salmoninarum, the causative agent of bacterial kidney disease, poses a major threat to both wild and aquaculture salmonid populations. Traditional detection methods typically involve lethal sampling to collect kidney tissues but are often impractical for species of conservation concern. This study evaluates nonlethal sampling techniques for detecting R. salmoninarum in Greenback Cutthroat Trout Oncorhynchus clarkii stomias by comparing mucus, blood, and ovarian fluid samples to conventional kidney tissue.</p><p><strong>Methods: </strong>During the 2019 spawning season, we collected samples from 781 adult fish and tested for R. salmoninarum via direct fluorescent antibody test (DFAT) and quantitative polymerase chain reaction (qPCR).</p><p><strong>Results: </strong>A total of 25 and 256 kidney tissues were positive by DFAT and qPCR, respectively. Of the three nonlethal samples tested, mucus swabs showed the highest percent correlation for detection with positive kidney tissues (DFAT = 47.6%, qPCR = 41.7%). Blood and ovarian fluid samples showed a lower percent correlation with positive kidney tissues (blood: DFAT = 12.0%, qPCR = 1.2%; ovarian fluid: DFAT = 12.5%, qPCR = 21.4%).</p><p><strong>Conclusions: </strong>Our results suggest that nonlethal mucus swabbing could serve as a practical alternative for monitoring R. salmoninarum, especially in conservation efforts where minimizing fish mortality is critical.</p>","PeriodicalId":15235,"journal":{"name":"Journal of aquatic animal health","volume":" ","pages":"192-198"},"PeriodicalIF":1.7,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145023359","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}