Waiting to Publish

Artemia parthenogenetica is an emerging species used in marine hatcheries in Vietnam. Disinfection during their cyst incubation is important, however, disinfectants might have side-effects. This study examined the effects of polyvinylpyrrolidone coated nanosilver particles (AgNPs) on A. parthenogenetica cyst hatching and nauplii development. Cysts were exposed to low (0.1, 0.4, 0.7 mg/L) and high (1, 4, and 7 mg/L) levels of AgNPs for 48h. The total Vibrio in incubated water and nauplii significantly decreased when AgNPs were applied, however, the hatching success significantly reduced when the AgNPs level exceeded 1 mg/L. Nauplii instar I and instar II were exposed to 10; 50; 100; 200; 500; 600; 700; 750; 800; 900 and 1000 mg/L to determine their LD50. The LD50-36h and LD50-48h of AgNP on Instar I were 136.5 and 53.21 mg/L while those on Instar II were 22.15 and 12.1 mg/L.    

Flavobacterium oreochromis is a major bacterial pathogen that causes columnaris disease in tilapia (Oreochromis spp.) and other freshwater fish species. assessed the antibiotic resistance profiles and minimum inhibitory concentrations (MICs) of F. oreochromis isolates obtained from infected tilapia cultured in Northern Vietnam. A total of 51 isolates retrieved from diseased fish collected in Hai Duong (n=23), Bac Ninh (n=16), and Hoa Binh (12 isolates) were used in the study. The bacteria were cultured on TYES agar, identified through morphological and biochemical analyses, and confirmed by PCR. Antimicrobial susceptibility testing employed the disk diffusion method against 16 antibiotics, while MICs of six frequently used antibiotics were determined via the broth microdilution method. The antimicrobial susceptibility test revealed that isolates exhibited high resistance to oxacillin (100%) and neomycin (76.5%),  moderate resistance to sulfamethoxazole-trimethoprim (37.3%), doxycycline (35.3%), and oxytetracycline (41.2%). Resistance to the remaining antibiotics was below 12%. Notably, all isolates were multidrug-resistant (MDR), exhibiting resistance to 2–10 antibiotics and 14 distinct resistance phenotypes were identified. MIC values ranged from 0.063 to 1 µg/ml for amoxicillin, 0.125–8 µg/ml for erythromycin, and 0.25–8 µg/ml for florfenicol. For oxytetracycline, doxycycline, and sulfamethoxazole-trimethoprim, MICs ranged from 0.016–1 µg/ml, 0.125–2 µg/ml, and 0.5–16 µg/ml, respectively. These findings highlight a decline in the efficacy of commonly used antibiotics against F. oreochromis, underscoring the necessity for routine antimicrobial susceptibility testing to promote rational antibiotic use in aquaculture.

Probiotics and prebiotics are increasingly encouraged in aquaculture to reduce antibiotic use. The present study aimed to investigate the effects of dietary supplementation of peptidoglycan or Lactobacillus plantarum or its combination on the growth performance, disease resistance, and immune status of striped catfish juvenile. Fish were fed on the commercial feed supplemented with various concentrations of peptidoglycan and Lactobacillus plantarum at 0, 5, 5, 2.5 + 2.5, and 5.0 + 5.0 per kg of feed, named to PP0.0, PG5.0, LP5.0, PP2.5, and PP5.0 treatments. Fish were then fed at a ration of 3% of fish body weight for 6 weeks. After feeding trial, fish were infected with Aeromonas veronii at 50% lethal dose (LD50, 107 CFU/mL). Blood samples were collected after 2, 4, and 6 weeks of experiment (T2, T4, and T6) and at second day after bacterial infection for hematological parameters and immune assays. The results demonstrated that supplementation with PP2.5 significantly improved growth performance and feed utilization in fish, while the LP5.0-based diet reduced mortality in A.veronii-challenged fish, indicating enhanced disease resistance. The modifications in hematology and immune status were affected by pro-, pre-, and synbiotics tested in this study. In conclusion, dietary supplementation with peptidoglycan and L.plantarum enhances growth, immunity, and disease resistance in striped catfish, supporting sustainable aquaculture practices for improved fish health and production efficiency. 

Depuration is a widely used post-harvest technique to reduce contaminants in shellfish. However, its effects on the nutritional quality of blood cockles (Anadara granosa) in the removal of microplastics (MPs) are not well understood. This study aimed to assess the variations in proximate composition and mineral content of cockle meat during a five-day MP depuration process. Cockles were subjected to a controlled depuration protocol, with samples collected at day 0, 3, and 5 for analysis of MP abundance and nutritional contents. Standard methods were used to determine MPs, proximate composition (including ash, protein, lipid, and carbohydrate), and mineral content (Ca, Mg, P, and Fe). The result showed that the five-day depuration period effectively reduced the mean MP load by 71.6%. The process removed larger particles and films, resulting in a higher relative abundance of smaller MPs (<500 µm) and fibers. However, this process resulted in a statistically significant decrease in the nutritional value of the cockles. By day 5, the contents of proximate composition and mineral content declined significantly. These findings demonstrate that while depuration is an effective process for reducing MP contamination in A. granosa, it decreases nutritional quality

Cryptocaryon irritans is an ectoparasitic protozoan responsible for white spot disease posing a significant threat to mariculture systems in Vietnam. This study aimed to isolate and propagate C. irritans, and to establish an experimental infection model in Trachinotus spp. (5-7 cm in lengh) under laboratory conditions. Between February and June 2025, a total of 106 fish samples were sourced from aquaculture operations in Quang Ninh and Khanh Hoa, revealing an average C. irritans infection rate of 59.43%, with the highest prevalence observed during March and April. Infected fish exhibited clinical signs including skin darkening, mucus loss, white spots on skin and gills, fin erosion, ulcerations, and tissue damage. The parasite was successfully cultured at the trophont stage and was propagated to the tomont and theront stages at 28-30°C, achieving a conversion efficiency of 61.7% after 48 hours and yielding an average of 150-300 theronts per tomont. These theronts introduced to Trachinotus spp. at a density of 5,000 theronts per 250L tank (50 fish) at a temperature of 28°C. The infection progressed rapidly, with trophont emergence observed within 2-3 days and complete mortality by day 7. The established infection model offers a robust platform for further research in epidemiology, immunology, and therapeutic interventions against C. irritans.

Coastal aquaculture zones, including areas for shrimp and mollusk farming, are subject to multiple stressors, such as internal farming activities, inland runoff, and extreme weather events driven by climate change. These factors contribute to spatiotemporal fluctuations in water quality, directly affecting aquaculture productivity and sustainability. This study aims to assess the current status of water quality in shrimp and clam farming areas across coastal districts of Nam Dinh Province, Vietnam, identify spatial and temporal variation trends, and propose appropriate management measures. Environmental parameters, including pH, dissolved oxygen (DO), salinity, alkalinity, COD, ammonium (N-NH₄⁺), nitrite (N-NO₂⁻), hydrogen sulfide (H₂S), total suspended solids (TSS), and total vibrio count, were monitored biweekly. The results indicated significant temporal fluctuations in water quality, with a clear deterioration trend during the rainy season and in storm-affected months, particularly in September, during the passage of Typhoon Yagi. In shrimp farming areas, water source quality tended to decline during June–August. Localized differences were also observed: Nghia Hung was characterized by low DO levels, while Hai Hau experienced large salinity fluctuations. In clam farming zones, water quality was lowest in June and July. Giao Thuy exhibited a higher frequency of salinity values falling below acceptable thresholds compared to Nghia Hung, suggesting greater variability in salinity levels. These findings provide a scientific basis for local authorities and farmers to plan adaptive water management strategies, such as storing high-quality water for use during periods of environmental stress.  

Fish is an important source of high-quality proteins, polyunsaturated omega-3 fatty acids, vitamins and other nutrients. Previous studies have emphasized that wild fish is chosen over cultivated fish by consumers. However, whether there exists a real nutritional difference between wild and cultivated fish is unknown. This paper reviews 41 studies available on quality differences between wild and cultivated fish of 27 species, including proximate compositions, mineral contents, fatty acids, amino acids profile, colour and texture. This review depicts that cultivated fishes have significantly lower moisture, but higher lipid content. However, protein and ash contents did not differ significantly between wild-caught and cultivated fish. Cultivated fish, sometimes, had lower polyunsaturated fatty acids percentage. Nevertheless, Eicosapentaenoic acid and Docosahexaenoic acid were remarkably higher than wild fish. Mineral contents of both cultivated and wild fish were rich in compositions and contents, whilst the wild counterparts had significantly higher contents of toxic elements. Colour and texture analysis showed that there were great differences between fish origins. These results suggest that both cultivated and wild fish possess virtuous quality attributes. We conjecture that the variations exist in the differentiated profiles depending on genders, diets, regions, seasons, farming modes and environmental conditions, at which fishes grow. This paper offers insights into the sustainable development for aqua products’ quality.

Biochar has been applied in various fields due to its unique physicochemical properties. Although its application has been extensively used in other countries, research within the Philippine context remains limited. With the growing demand and popularity of biochar, understanding the trends in its application within the country could provide direction for future research on the material. The result of the bibliometric analysis showed that the trend in biochar research in the Philippines is gaining traction and popularity for various uses. Although still at a slower pace than its neighboring countries, biochar research is gaining popularity in the Philippines due to its numerous applications, primarily used in agriculture and the environment. Currently, clustered areas of biochar research in the country include identifying suitable biomass for pyrolysis, exploring the adsorptive properties of biochar, and utilizing it as a carrier for arbuscular mycorrhizal fungi (AMF). The limited clusters imply fewer applications, indicating the potential for biochar to expand into various other utilizations. Additionally, aside from research and development funding, there is a noticeable gap in international collaborations, and the number of dedicated experts in biochar research is still insufficient. These factors must be addressed, which are vital for advancing biochar research in the Philippines.