Uun Yanuhar, Heru Suryanto, Herly Evanuarini, Nico Rahman Caesar, Defa Rizqi Machfuda, Nezya Pramudya Wardani, Aisha Surya Ananda
Grouper farming underpins Indonesia’s coastal livelihoods and supplies both domestic and export markets, yet disease-especially Viral Nervous Necrosis (VNN) in juveniles-remains a major constraint. Conventional tools (antibiotics, standard vaccines) have delivered limited protection, motivating alternative approaches. Leveraging nanotechnology, we evaluated a ZnO-chitosan nanoconjugate carrying a recombinant Chlorella vulgaris antigen for antiviral protection in cantang grouper (E. fuscoguttatus×E. lanceolatus). In a 56-day randomized block trial, 160 fish were allocated to 5 treatments (T1-T5) and two controls. Endpoints included growth (length, weight, survival rate, SR; relative percent survival, RPS), hematology (erythrocytes, leukocytes, hematocrit, hemoglobin), gill histopathology, and flow cytometry of CD4⁺/CD8⁺ T-cell markers. The 33 µL regimen (T3) was consistently superior: length rose from 9.94 → 12.73 cm and weight from 13.57 → 18.00 g, with SR = 95% and RPS = 92%. Hematological profiles improved across all indices; gill lesions were minimal (mild edema, hyperplasia, lamellar fusion); and immunophenotyping showed moderated CD4⁺ activation alongside a marked increase in CD8⁺ expression, indicating effective cellular immunity. While T1 and T4 performed well and T2/T5 yielded moderate responses, T3 delivered the most balanced protection and significantly lowered viral load. These results highlight the promise of recombinant Chlorella antigens formulated in ZnO-chitosan nanoconjugates to strengthen grouper health and bolster aquaculture sustainability. © 2026, Walailak University. All rights reserved.
Faculty of Fisheries and Marine Sciences, Brawijaya University, East Java, Indonesia; Department of Mechanical and Industrial Engineering, Faculty of Engineering, Universitas Negeri Malang, Malang, 65145, Indonesia; Department of Animal Product Technology, Faculty of Animal Science, Brawijaya University, Malang, 65141, Indonesia; Faculty of Veterinary Medicine, Brawijaya University, East Java, Indonesia
