Evidence cluster — Aquarium fish (teleost fish) husbandry, health & nutrition (peer-reviewed, Europe PMC)

Evidence: Aquarium fish (teleost fish) husbandry, health & nutrition

Source: Europe PMC (Europe PubMed Central) REST search — first-hand peer-reviewed abstract records, pulled 2026-08-01. Queries covered husbandry, health/disease/parasitology, and nutrition/feeding for teleost fish. The cluster returns 11 representative studies with abstracts below. Abstract text is verbatim from source; each study is traceable by PMID.

Studies

• PMID 42188959 (2026, Veterinary sciences) — Systemic Granulomatous Mycobacteriosis in Orbiculate Batfish (&lt;i&gt;Platax orbicularis&lt;/i&gt;) Associated with &lt;i&gt;Mycobacterium marinum&lt;/i&gt;-like Organism in an Aquarium in South Korea.. Abstract (opening): In this report, we describe systemic granulomatous mycobacteriosis in an orbiculate batfish from an aquarium in South Korea. Gross examination of the deceased fish showed multifocal nodular lesions in multiple internal organs including the gills, spleen, and kidney. Histopathological analysis demonstrated severe chronic systemic granulomatous inflammation, and Ziehl-Neelsen staining highlighted abundant intralesional acid-fast bacilli. Molecular analysis based on partial sequencing of the 16S ribosomal RNA (rRNA) and heat shock protein 65 (<i>hsp65</i>) genes showed that the detected organism was most closely related to <i>Mycobacterium marinum.</i> Because the molecular analysis was performed using partial sequences obtained from formalin-fixed, paraffin-embedded tissues, definitive species-level identification was not possible. This case represents systemic granulomatous mycobacteriosis associated with a <i>Mycobacterium marinum</i>-like organism in orbiculate batfish in an aquarium in South Korea and emphasizes the need for continuous disease surveillance and improved diagnostic awareness of non-tuberculous mycobacterial infections in ornamental and public aquarium fish. *[CC BY — Open Access, verbatim with attribution.]*

Source: https://pubmed.ncbi.nlm.nih.gov/42188959/

• PMID 42262143 (2026, Ecological applications : a publication of the Ecological Society of America) — Evaluating species at risk in data-limited fisheries: A productivity-susceptibility analysis for marine aquarium fish.. Abstract (opening): The marine aquarium trade (MAT) is a significant global industry harvesting millions of wild-caught, live coral reef fishes for public and private aquaria markets in the United States and Europe annually, while supporting fisher livelihoods in the Indo-Pacific. This diverse and species-rich trade is considered data-limited, creating barriers to quantifying the current and future socio-ecological sustainability of the fishery. We present a revised and expanded productivity-susceptibility analysis (PSA) that serves as a holistic risk assessment to estimate the vulnerability of marine aquarium fish to overfishing. Our global analysis includes 306 species that are actively in trade. Improvements to the PSA framework from previous research including novel susceptibility factors, methods to overcome missing data for individual species factors, and assessing a large, diverse group of marine fish under a single, targeted assessment framework. Our results show that an overwhelming 81.4% of species evaluated fall into the least or moderately vulnerable classification, while the remaining species (n = 57) have higher vulnerability scores designating them as high priority for localized assessment and management initiatives. Most teleost fish in the trade are considered sustainable, while eels and elasmobranchs have the highest vulnerability scores. A comparative case study between our PSA and the popular FishBase vulnerability tool illustrates how the latter can be ill-suited to handle the data limitations common to nonfood fishes. Our study demonstrates how the PSA is a robust, data-limited fishery assessment to prioritize species in the MAT for further assessment, monitoring, and management. *[CC BY — Open Access, verbatim with attribution.]*

Source: https://pubmed.ncbi.nlm.nih.gov/42262143/

• PMID 41391259 (2026, Computational biology and chemistry) — *[Paraphrased derived summary — non-Open-Access source.]* Using quantitative structure-property relationship (QSPR) analysis with reverse degree-based topological indices, this study explored links between drug molecular structure and therapeutic efficacy against fin rot, a common bacterial aquarium-fish disease linked to poor environmental conditions. Several routinely used fin-rot drugs were analysed, correlating their topological indices with properties such as molar weight, complexity, polarizability, and exact mass; the authors suggest the approach could support optimised drug selection and design.

Source: https://pubmed.ncbi.nlm.nih.gov/41391259/

• PMID 41060374 (2026, Conservation biology : the journal of the Society for Conservation Biology) — Extent of threats to marine fish from the online aquarium trade in the United States.. Abstract (opening): The global marine aquarium hobby is a multibillion-dollar industry, largely driven by demand from the United States. Much of this trade occurs online. We web scraped 4 major US-based e-commerce platforms selling marine aquarium fish to determine the retail price and source (wild capture, aquaculture, or both) of 13 families of ray-finned marine fish (Actinopterygii). We supplemented this with ecological and economic trait data from FishBase and the International Union for Conservation of Nature (IUCN). Across all platforms and 13 popular fish taxonomic families, we found 734 unique species for sale, 89.2% (655 species) of which were sourced exclusively from the wild. A total of 45 species were of conservation concern (20 threatened species and 25 additional species with decreasing population trends), 38 of which were sourced solely from the wild. Retail price was significantly correlated with source, body length, minimum occupied depth, and schooling behavior. A further 100 species for sale were not listed as being in the aquarium trade in FishBase or by the IUCN, indicating incomplete information on this fishery in 2 important databases. For 58 species (encompassing 71 variants) with both wild-caught and captive-bred individuals for sale, aquaculture fish were a mean 28.1% (95% confidence interval 15.3) cheaper than their wild-caught counterparts. *[CC BY — Open Access, verbatim with attribution.]*

Source: https://pubmed.ncbi.nlm.nih.gov/41060374/

• PMID 41857250 (2026, Parasitology research) — First record of Camallanus cotti (Fujita, 1927) in traded guppies (Poecilia reticulata) from India.. Abstract (opening): The guppy Poecilia reticulata is a widely traded ornamental fish species, valued for its popularity in aquariums globally. Parasitic infections pose a significant threat to both ornamental culture and native fish populations. This study records the first occurrence of the intestinal nematode Camallanus cotti (Fujita, 1927) in guppies from India, confirmed through both morphological and molecular analysis. Sixteen guppies were collected from the Kolathur ornamental fish market, Chennai, Tamil Nadu. Examination revealed that 11 fish (68.75%) were infected with red thread-like nematodes protruding from the anus. A total of 41 worms were recovered, with a mean intensity of 3.73 and a mean abundance of 2.56 worms per fish. Light microscopy confirmed diagnostic features of C. cotti, including the robust cephalic capsule and scanning electron microscopy illustrates the attachment of the parasite to intestinal wall. Molecular characterization using 18 S rRNA gene sequencing (GenBank Accession PX446961.1) showed 99.84% similarity with reference sequences, validating the morphological identification. Infected guppies exhibited visible clinical signs, including abdominal distension and threadlike worms protruding from the anus. The findings highlight the risk posed by C. cotti to ornamental fish health and emphasize the importance of quarantine, monitoring, and surveillance to prevent its spread through the aquarium trade. *[CC BY — Open Access, verbatim with attribution.]*

Source: https://pubmed.ncbi.nlm.nih.gov/41857250/

• PMID 42116709 (2026, The Journal of experimental biology) — Gut microbial composition varies with host metabolic phenotype in juvenile Atlantic salmon.. Abstract (opening): Standard metabolic rate (SMR) influences growth, behaviour and energy use in fish, yet its relationship with gut microbiota remains unclear. Here, we combined physiological measurements with 16S rRNA sequencing of foregut and hindgut tissue to test whether gut microbial communities differ with metabolic phenotype in juvenile Atlantic salmon. High-SMR fish showed greater growth efficiency and lower body water content than low-SMR fish, indicating higher fat levels. In contrast, microbial differences were most evident in the foregut, where low-SMR fish exhibited significantly higher alpha diversity. Microbial beta-diversity analyses revealed clear segregation among metabolic groups, and distance-based redundancy analysis showed that both SMR and body mass strongly explained variation in foregut microbial composition. Correlation analysis identified a negative association between SMR and members of the Rhodobacteraceae family, which were consistently more abundant in the foregut of low-SMR fish. Together, these findings indicate that the metabolic phenotype is associated with distinct patterns of energy utilisation and gut microbiota composition, suggesting that foregut microbial communities may contribute to individual differences in metabolic strategy. *[CC BY — Open Access, verbatim with attribution.]*

Source: https://pubmed.ncbi.nlm.nih.gov/42116709/

• PMID 42511625 (2026, International journal of molecular sciences) — *[Paraphrased derived summary — non-Open-Access source.]* Channel catfish (Ictalurus punctatus) exposed to beta-glucan were analysed by ChIP-seq for four histone modifications in the anterior kidney. H3K4me3-associated upregulation mapped to metabolism, signalling, pathogen recognition, and immune regulation, while H3K27ac and H3K4me1 marks linked to apoptosis, cytoskeletal dynamics, autophagy, adhesion, and stress responses, and H3K27me3 conferred loci-specific repression. The authors interpret the coordinated chromatin and transcriptional remodelling as trained innate immunity, supporting beta-glucan as a functional immunomodulator in aquaculture.

Source: https://pubmed.ncbi.nlm.nih.gov/42511625/

• PMID 42413203 (2026, Veterinary immunology and immunopathology) — *[Paraphrased derived summary — non-Open-Access source.]* This review synthesises innate immune modulation in teleost fish, arguing that immune-gene expression should be interpreted as a phased, coordinated response (early inflammatory activation through to regulatory homeostasis) rather than a simple linear measure of immune strength. It highlights the Toll-like receptor-MyD88-NF-kappaB axis and contrasts pro-inflammatory mediators (IL-1beta, TNF-alpha, IL-8, NF-kappaB) with regulatory ones (IL-10, TGF-beta), offering a framework for context-sensitive fish-health assessment in aquaculture.

Source: https://pubmed.ncbi.nlm.nih.gov/42413203/

• PMID 42001862 (2026, Veterinary immunology and immunopathology) — *[Paraphrased derived summary — non-Open-Access source.]* This review examines antibacterial immunity in teleost fish, identifying bacterial infection as the major barrier to sustainable aquaculture and stressing that innate-adaptive immune integrity is undermined by common farming stressors (temperature change, water quality, chronic stress, microbiome diversity). It advocates an 'eco-immunology' framework integrating innate-adaptive crosstalk with environmentally driven immune reprogramming and autophagy-mediated control of chronic bacterial infection.

Source: https://pubmed.ncbi.nlm.nih.gov/42001862/

• PMID 42069193 (2026, Fish & shellfish immunology) — *[Paraphrased derived summary — non-Open-Access source.]* In Asian swamp eel, dietary Bacillus velezensis D1 was shown to interact selectively with host Toll-like receptor 5 via the flagellar hook protein FlgE (validated at ~48 kDa). Supplementation altered expression of TLR5, IL-6, IL-1beta, and TNF-alpha with early upregulation (6-12 h) and peaks at 24-48 h, improved gut architecture (villus height/width, wall and muscle thickness), and shifted the gut microbiota (527 versus 239 OTUs in controls; Firmicutes and Actinobacteria increased, Proteobacteria decreased), indicating TLR5-linked immune and microbial restructuring.

Source: https://pubmed.ncbi.nlm.nih.gov/42069193/

• PMID 42516369 (2026, Frontiers in immunology) — *[Paraphrased derived summary — non-Open-Access source.]* In common carp (Cyprinus carpio), the authors profiled expression of 13 secreted AID/APOBEC-like deaminase (snad1) genes across embryonic and early larval development. Twelve genes showed significant stage-dependent variation forming four temporal patterns; four were maternally deposited (snad_318, snad_800, snad_835, snad_810) and three showed delayed post-zygotic activation (snad_409, snad_208, snad_962), coinciding with post-hatching immune maturation. The work gives the first comprehensive developmental map of these genes.

Source: https://pubmed.ncbi.nlm.nih.gov/42516369/

Source text: pdf-raw/evidence/europepmc_fish_husbandry_health_2026-08-01.txt (Europe PMC first-hand abstracts, pulled 2026-08-01).

License & attribution

Mixed licensing per COPYRIGHT_POLICY §3: Open Access (CC BY / CC BY-NC / CC BY-NC-ND) studies are reproduced verbatim with attribution under their specific CC license; non-Open-Access studies are paraphrased as derived fact summaries (numbers and proper nouns preserved, sentences rewritten). Original records:

• https://pubmed.ncbi.nlm.nih.gov/42188959/
• https://pubmed.ncbi.nlm.nih.gov/42262143/
• https://pubmed.ncbi.nlm.nih.gov/41391259/
• https://pubmed.ncbi.nlm.nih.gov/41060374/
• https://pubmed.ncbi.nlm.nih.gov/41857250/
• https://pubmed.ncbi.nlm.nih.gov/42116709/
• https://pubmed.ncbi.nlm.nih.gov/42511625/
• https://pubmed.ncbi.nlm.nih.gov/42413203/
• https://pubmed.ncbi.nlm.nih.gov/42001862/
• https://pubmed.ncbi.nlm.nih.gov/42069193/
• https://pubmed.ncbi.nlm.nih.gov/42516369/

Cleaning removal log (2026-08-05, codebuddy)

PMID 42048776 — paediatric emergency-dept distraction study on children using aquarium-fish observation; human subjects, not fish