Indonesia’s export fishery commodities have high economic value and prices, namely the grouper fish. The grouper fish are cruciferous or hybridized. The Cantang grouper (Epinephelus fuscoguttatus lanceoulatus) is a mating of female Tiger Grouper (Epinephelus fuscoguttatus) and male Kertang Grouper (Epinephelus lanceoulatus). The problem in the production of Cantang grouper is a disease, one of which is a virus. The production of Indonesia’s cultivation grouper fish in 2020 was reported to reach 9,478.03 tons, a decrease of 31.5% compared to 2019 reaching 13,828.93 tons, the failure was due to VNN attacks.
In Indonesia, VNN (Viral Nervous Necrosis) is attacking the grouper cultivation (in 1997-present, global aquaculture production losses due to VNN virus infection attacks reached USD 6 billion /year, with losses of about 
40% of the total of all current global cultural aquaculture production. According to Yanuhar, et al. (2020), Viral Nervous Necrosis (VNN) is a type of nodaviridae virus that is an RNA virus, with a diameter of 20-25 nm. VNN usually attacks fish on juvenile stadia and larva. The main target of VNN is the brain and eye nervous system that will actively replicate in these organs causing extensive vacuolation of fish organ tissue to be disrupted [4]. These VNN can be transmitted horizontally from infected fish by exposure to water contaminated with VNNs and other organisms. VNN can infect grouper fish starting from less than 10 days old and will reduce the mortality rate after the fish is more than 3 months old along can be detected as less healthy or sick fish. The length of the nitrogenous base VNN is 294 bp.
This research was conducted in February-April 2022 at UD. Giso Bangkit, Laboratory of Animal Physiology of UIN Malang, Laboratory of Molecular Biology, Faculty of Science and Technology of UIN Malang, Laboratory of Anatomical Pathology of Faculty of Medicine of UB and UB bioscience institute. The research method used in this study is experimental where the data retrieval technique is based on the primary data used in the form of the influence of recombinant nanovaccination from microalgae of Chlorella Vulgaris against the long growth of fish weight and eye tissue in Cantang grouper fish (Epinephelus fuscoguttatus lanceolatus) infected with Viral Nervous Necrosis (VNN).
Fish infected with VNN show altered swimming behaviors such as swimming in a spinning and fast way. Therefore, fish can suffer erratic injuries due to mechanical damage when the fish hits the wall and make the sick fish easier to detect. Fish infected with VNN have numerous wounds on their mouths and chipped fins that occur as a result of changes in swimming movements. This condition indicates that the fish are starting to lose their balance in swimming so that they can often be seen hitting the walls and bottom of the pond. The results of behavioral observations in the sample fish shown in Table 1.
According to Kaus and Mishra (2019) [17], vacuolation is empty spaces in the cytoplasm that are formed due to pathogenic infections in cells so that death occurs and is irreversible. Vacuolization is characterized by the presence of vacuoles from the loss of cell contents. Vacuolation is formed as a result of VNN infection through the circulatory system (Fig. 1). Based on the results of the research that has been carried out, the average results of vacuolation damage scoring in the eye tissues of the Cantang grouper fish can be obtained.
The administration of the C. vulgaris recombinant (p-PerCv) vaccine also has an influence on the growth of the length and weight of the Cantang grouper. This is because, the growth in length and weight of Cantang grouper from the treatment group was different from the control group (0.039< 0.05). In addition, the administration of C. vulgaris recombinant vaccine (p-PerCv) with different doses exerts a different influence on the degree of damage to eye tissue both damage to vacuolization, necrosis, and hypertrophy which can be seen from the results of the Tukey Test. The results of the Tukey test showed that the treatment that had a significant influence was on the treatment of T1 (treatment of healthy fish + 33 μl of C. vulgaris recombinant vaccine (p-PerCv) + 8.5 μl of Chitosan nanoparticles). The quality of water as a supporting factor in water quality management is temperature (27.7-30.2 °C), pH (7.1-8.2), DO (4-7 mg/L), CO2 (20-22 mg/L), salinity (29-32.5 g/L), nitrates (0.02-0.07 mg/L), ammonia (0.5-0.75 mg/L), and phosphates (0.07-0.25 mg/L). The water quality in the maintenance tank is still appropriate and can not achieve the survival of the Cantang grouper fish.
Author: Prof. Dr. Gunanti Mahasri, Ir., M.Si
Details on the research: Uun Yanuhar1, Gunanti Mahasri2, Heru Suryanto3, Salman Bin Yunus Syamlan1, Nur Sakinah Junirahma4, and Nico Rahman Caesar5. 2024. The Effect of Chitosan Hybrid Nanoparticle-Based Nanovaccines (C-Nps) on the Tissue Demage of Cantang Grouper Fish Infected with Viral Nervous Necrosis. AIP Conference Proceedings.
