{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,15]],"date-time":"2026-09-15T11:08:08Z","timestamp":1789470488571,"version":"build-2803163510"},"reference-count":37,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,9,13]],"date-time":"2026-09-13T00:00:00Z","timestamp":1789257600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002855","name":"National Key R&D Program of China","doi-asserted-by":"publisher","award":["2022YFE0203900"],"award-info":[{"award-number":["2022YFE0203900"]}],"id":[{"id":"10.13039\/501100002855","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100011798","name":"Earmarked Fund for the Modern Agroindustry Technology Research System","doi-asserted-by":"publisher","award":["CARS-46-G01"],"award-info":[{"award-number":["CARS-46-G01"]}],"id":[{"id":"10.13039\/501100011798","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100005906","name":"Central Public-Interest Scientific Institution Basal Research Fund CAFS","doi-asserted-by":"publisher","award":["2023TD26"],"award-info":[{"award-number":["2023TD26"]}],"id":[{"id":"10.13039\/501100005906","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100008238","name":"Hebei Provincial Research Project","doi-asserted-by":"publisher","award":["2023HBQZYCSB019"],"award-info":[{"award-number":["2023HBQZYCSB019"]}],"id":[{"id":"10.13039\/501100008238","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Curr. Issues Mol. Biol.","CIMB"],"abstract":"<jats:p>Mass mortality outbreaks threaten cultured big-belly seahorses (Hippocampus abdominalis), but gut microbial changes associated with disease and host sex remain unclear. We analyzed 36 seahorses from a single aquaculture system, classified as apparently normal males (NMHA), diseased males (EMHA), apparently normal females (NFMHA), and diseased females (EFMHA). Intestinal contents from three individuals were pooled per biological replicate, yielding three pooled replicates per group and 12 microbiome samples in total (effective n = 3 per group). The V3\u2013V4 region of the 16S rRNA gene was sequenced, and ASVs were inferred using DADA2 in QIIME 2. \u03b1-diversity showed marginal overall group differences, whereas exploratory two-way ANOVA indicated effects of health status and Health \u00d7 Sex interactions on observed ASVs, Shannon, and Simpson indices. Bray\u2013Curtis PERMANOVA also detected significant effects of health status and the Health \u00d7 Sex interaction on community structure. Pseudomonadota dominated all groups, while Vibrio was strongly enriched in diseased females, reaching 86.94 \u00b1 13.03%. LEfSe identified Vibrio\/Vibrionaceae as biomarkers of diseased females, whereas Arcobacteraceae and Litoreibacter characterized diseased males. PICRUSt2-based prediction suggested higher predicted representation of pathways related to signal transduction, membrane transport, biofilm formation, chemotaxis, and flagellar assembly in diseased groups. Overall, gut microbiota dysbiosis during the outbreak showed sex-stratified patterns, with pronounced Vibrio enrichment representing a prominent disease-associated microbial feature, particularly in females.<\/jats:p>","DOI":"10.3390\/cimb48090936","type":"journal-article","created":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T13:05:26Z","timestamp":1789391126000},"page":"936","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Sex-Stratified Gut Microbiota Dysbiosis in Cultured Big-Belly Seahorses During a Mass Mortality Outbreak"],"prefix":"10.3390","volume":"48","author":[{"given":"Hangzhou","family":"Guo","sequence":"first","affiliation":[{"name":"State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, China-ASEAN Belt and Road Joint Laboratory on Mariculture Technology (Qingdao), Qingdao 266071, China"},{"name":"Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"data-curation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"software","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2987-6228","authenticated-orcid":false,"given":"Zhibin","family":"Sun","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, China-ASEAN Belt and Road Joint Laboratory on Mariculture Technology (Qingdao), Qingdao 266071, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"software","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Huiyu","family":"Xiao","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, China-ASEAN Belt and Road Joint Laboratory on Mariculture Technology (Qingdao), Qingdao 266071, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"data-curation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"}]},{"given":"Pengfei","family":"Yan","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, China-ASEAN Belt and Road Joint Laboratory on Mariculture Technology (Qingdao), Qingdao 266071, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0473-498X","authenticated-orcid":false,"given":"Xin\u2019an","family":"Wang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, China-ASEAN Belt and Road Joint Laboratory on Mariculture Technology (Qingdao), Qingdao 266071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Siqi","family":"Wang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, China-ASEAN Belt and Road Joint Laboratory on Mariculture Technology (Qingdao), Qingdao 266071, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"data-curation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3766-4372","authenticated-orcid":false,"given":"Annita","family":"Yong Seok-Kian","sequence":"additional","affiliation":[{"name":"Higher Institution Centre of Excellence (HICoE), Institut Marin Borneo, University Malaysia Sabah, Kota Kinabalu 88400, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aijun","family":"Ma","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, China-ASEAN Belt and Road Joint Laboratory on Mariculture Technology (Qingdao), Qingdao 266071, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"funding-acquisition","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"439","DOI":"10.1111\/jfd.12254","article-title":"Diseases of captive yellow seahorse Hippocampus kuda Bleeker, pot-bellied seahorse Hippocampus abdominalis Lesson and weedy seadragon Phyllopteryx taeniolatus (Lac\u00e9p\u00e8de)","volume":"38","author":"LePage","year":"2015","journal-title":"J. Fish Dis."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"867","DOI":"10.1111\/are.14421","article-title":"Novel co-infection by ciliates and Barentsia outbreak in large-scale cultured lined seahorse (Hippocampus erectus) in the northern China","volume":"51","author":"Chen","year":"2020","journal-title":"Aquac. Res."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"263","DOI":"10.1111\/jwas.12189","article-title":"Comparison of the intestinal bacterial flora in healthy and intestinal-diseased seahorses Hippocampus trimaculatus, Hippocampus erectus, and Hippocampus spinosissimus","volume":"46","author":"Li","year":"2015","journal-title":"J. World Aquac. Soc."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"101466","DOI":"10.1016\/j.aqrep.2023.101466","article-title":"Supplementation with Enterococcus faecium enhances growth performance, intestinal health and immunity of big-belly seahorses (Hippocampus abdominalis) during diet conversion","volume":"28","author":"Tian","year":"2023","journal-title":"Aquac. Rep."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"195","DOI":"10.3354\/dao03350","article-title":"Isolation, identification, and histopathological analysis of Vibrio tubiashii from lined seahorse Hippocampus erectus","volume":"133","author":"Shao","year":"2019","journal-title":"Dis. Aquat. Org."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1007\/s10482-009-9398-4","article-title":"Isolation of Vibrio alginolyticus and Vibrio splendidus from captive-bred seahorses with disease symptoms","volume":"97","author":"Planas","year":"2010","journal-title":"Antonie Van Leeuwenhoek"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"730","DOI":"10.1007\/s00284-019-01859-6","article-title":"Altered intestinal microbiota composition associated with enteritis in yellow seahorses Hippocampus kuda (Bleeker, 1852)","volume":"77","author":"Wang","year":"2020","journal-title":"Curr. Microbiol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"391","DOI":"10.1016\/j.fsi.2020.01.049","article-title":"Edwardsiella tarda induces enteritis in farmed seahorses (Hippocampus erectus): An experimental model and its evaluation","volume":"98","author":"Wang","year":"2020","journal-title":"Fish Shellfish Immunol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"110024","DOI":"10.1016\/j.fsi.2024.110024","article-title":"Host-intestinal microbiota interactions in Edwardsiella piscicida-induced lethal enteritis in big-belly seahorses: Novel insights into the role of carbohydrate-active enzymes and host transcriptional responses","volume":"156","author":"Jia","year":"2025","journal-title":"Fish Shellfish Immunol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"111124","DOI":"10.1016\/j.cbpb.2025.111124","article-title":"Microplastic and Vibrio harveyi co-exposure induces oxidative stress in big-belly seahorse Hippocampus abdominalis","volume":"279","author":"Kim","year":"2025","journal-title":"Comp. Biochem. Physiol. B Biochem. Mol. Biol."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Zhang, L., Wang, F., Jia, L., Yan, H., Gao, L., Tian, Y., Su, X., Zhang, X., Lv, C., and Ma, Z. (2023). Edwardsiella piscicida infection reshapes the intestinal microbiome and metabolome of big-belly seahorses: Mechanistic insights of synergistic actions of virulence factors. Front. Immunol., 14, Erratum in: Front. Immunol.\u00a02023, 14, 1135588.","DOI":"10.3389\/fimmu.2023.1222662"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Egerton, S., Culloty, S., Whooley, J., Stanton, C., and Ross, R.P. (2018). The gut microbiota of marine fish. Front. Microbiol., 9.","DOI":"10.3389\/fmicb.2018.00873"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"464","DOI":"10.1016\/j.aquaculture.2015.06.033","article-title":"A new view of the fish gut microbiome: Advances from next-generation sequencing","volume":"448","author":"Ghanbari","year":"2015","journal-title":"Aquaculture"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1111\/jam.13415","article-title":"Fish intestinal microbiome: Diversity and symbiosis unravelled by metagenomics","volume":"123","author":"Tarnecki","year":"2017","journal-title":"J. Appl. Microbiol."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Butt, R.L., and Volkoff, H. (2019). Gut microbiota and energy homeostasis in fish. Front. Endocrinol., 10.","DOI":"10.3389\/fendo.2019.00009"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Sehnal, L., Brammer-Robbins, E., Wormington, A.M., Blaha, L., Bisesi, J., Larkin, I., Martyniuk, C.J., Simonin, M., and Adamovsky, O. (2021). Microbiome composition and function in aquatic vertebrates: Small organisms making big impacts on aquatic animal health. Front. Microbiol., 12.","DOI":"10.3389\/fmicb.2021.567408"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"280","DOI":"10.1111\/lam.13511","article-title":"High-throughput sequencing-based analysis of bacterial communities associated with Barbour\u2019s seahorses (Hippocampus barbouri) from Surigao del Norte, Philippines","volume":"73","author":"Ortega","year":"2021","journal-title":"Lett. Appl. Microbiol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"590","DOI":"10.1152\/physiolgenomics.00039.2024","article-title":"Deciphering taxonomic and functional patterns of microbial communities associated with the tiger tail seahorse (Hippocampus comes)","volume":"56","author":"Dalayap","year":"2024","journal-title":"Physiol. Genom."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"e240159","DOI":"10.1530\/REP-24-0159","article-title":"Changes to the reproductive microbiome of the brood pouch during male pregnancy in seahorses (Hippocampus abdominalis)","volume":"169","author":"Wang","year":"2025","journal-title":"Reproduction"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"114711","DOI":"10.1016\/j.ecoenv.2023.114711","article-title":"Microbial profiles and immune responses in seahorse gut and brood pouch under chronic exposure to environmental antibiotics","volume":"253","author":"Zhao","year":"2023","journal-title":"Ecotoxicol. Environ. Saf."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"738366","DOI":"10.1016\/j.aquaculture.2022.738366","article-title":"Comparative analyses reveal sex-biased gut microbiota in cultured subadult pufferfish Takifugu obscurus","volume":"558","author":"Chen","year":"2022","journal-title":"Aquaculture"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Piazzon, M.C., Naya-Catal\u00e0, F., Sim\u00f3-Mirabet, P., Picard-S\u00e1nchez, A., Roig, F.J., Calduch-Giner, J.A., Sitj\u00e0-Bobadilla, A., and P\u00e9rez-S\u00e1nchez, J. (2019). Sex, age, and bacteria: How the Intestinal microbiota is modulated in a protandrous hermaphrodite fish. Front. Microbiol., 10.","DOI":"10.3389\/fmicb.2019.02512"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"37065","DOI":"10.1038\/s41598-025-20869-y","article-title":"Comprehensive insight into gut microbiota and their interaction with fatty acid profiles in Channa striata during the spawning season","volume":"15","author":"Sharma","year":"2025","journal-title":"Sci. Rep."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Sundaray, J.K., Mohapatra, M., Rasal, A., Udit, U.K., Mohanty, S., Mohanty, D., Das, I.I., Sahoo, L., and Sahoo, P.K. (2025). Sex-specific gut microbiome dynamics in Labeo catla: Links to reproductive hormones, metabolic dimorphism, and environmental factors. Front. Microbiol., 16.","DOI":"10.3389\/fmicb.2025.1651975"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Valeri, F., and Endres, K. (2021). How biological sex of the host shapes its gut microbiota. Front. Neuroendocrinol., 61.","DOI":"10.1016\/j.yfrne.2021.100912"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"101459","DOI":"10.1016\/j.aqrep.2022.101459","article-title":"Pathology and pathogenesis of Vibrio infection in fish: A review","volume":"28","author":"Manchanayake","year":"2023","journal-title":"Aquac. Rep."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"231","DOI":"10.1007\/s42995-020-00037-z","article-title":"Vibrio harveyi: A serious pathogen of fish and invertebrates in mariculture","volume":"2","author":"Zhang","year":"2020","journal-title":"Mar. Life Sci. Technol."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Hao, Y., Zhao, Y., Zhang, Y., Liu, Y., Wang, G., He, Z., Cao, W., Han, T., Zhang, X., and Zhang, Z. (2023). Population response of intestinal microbiota to acute Vibrio alginolyticus infection in half-smooth tongue sole (Cynoglossus semilaevis). Front. Microbiol., 14.","DOI":"10.3389\/fmicb.2023.1178575"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"217","DOI":"10.1093\/dnares\/dst052","article-title":"Design and experimental application of a novel non-degenerate universal primer set that amplifies prokaryotic 16S rRNA genes with a low possibility to amplify eukaryotic rRNA genes","volume":"21","author":"Mori","year":"2014","journal-title":"DNA Res."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"852","DOI":"10.1038\/s41587-019-0209-9","article-title":"Reproducible, interactive, scalable and extensible microbiome data science using QIIME 2","volume":"37","author":"Bolyen","year":"2019","journal-title":"Nat. Biotechnol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"581","DOI":"10.1038\/nmeth.3869","article-title":"DADA2: High-resolution sample inference from Illumina amplicon data","volume":"13","author":"Callahan","year":"2016","journal-title":"Nat. Methods"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"996","DOI":"10.1038\/nbt.4229","article-title":"A standardized bacterial taxonomy based on genome phylogeny substantially revises the tree of life","volume":"36","author":"Parks","year":"2018","journal-title":"Nat. Biotechnol."},{"key":"ref_33","first-page":"32","article-title":"A new method for non-parametric multivariate analysis of variance","volume":"26","author":"Anderson","year":"2001","journal-title":"Austral Ecol."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Zhou, R., Weng, S., and He, J. (2025). Bacterial infection disrupts the intestinal bacterial community and facilitates the enrichment of pathogenic bacteria in the intestines of Penaeus vannamei. Microorganisms, 13.","DOI":"10.3390\/microorganisms13040864"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1007\/s00251-020-01194-2","article-title":"The intersection of stress, sex and immunity in fishes","volume":"73","author":"Campbell","year":"2021","journal-title":"Immunogenetics"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Li, S., Liu, X., Shen, F., Lin, T., and Zhang, D. (2024). First insight of the genome-wide association study and genomic prediction into enteritis disease (Vibrio harveyi) resistance trait in the lined seahorse (Hippocampus erectus). Front. Immunol., 15.","DOI":"10.3389\/fimmu.2024.1474746"},{"key":"ref_37","first-page":"AQUAST1629","article-title":"Experimental infection and treatment of Vibrio alginolyticus and Vibrio splendidus in captive bred spotted seahorse, Hippocampus kuda larvae","volume":"24","author":"Ranasinghe","year":"2024","journal-title":"Aquac. Stud."}],"container-title":["Current Issues in Molecular Biology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1467-3045\/48\/9\/936\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,15]],"date-time":"2026-09-15T10:58:21Z","timestamp":1789469901000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1467-3045\/48\/9\/936"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,13]]},"references-count":37,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["cimb48090936"],"URL":"https:\/\/doi.org\/10.3390\/cimb48090936","relation":{},"ISSN":["1467-3045"],"issn-type":[{"value":"1467-3045","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,13]]}}}