• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.960-966
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• 2022

We aimed to determine the dietary myo-inositol (MI) requirements of Pacific white shrimp Litopenaeus vannamei. A basal diet was formulated without myo-inositol (M0) and a negative control diet (M0-) was prepared by adding tetracycline hydrochloride to the basal diet to prevent intestinal inositol synthesis. Five MI diets were prepared by adding MI at 300, 600, 900, 1,200 and 1,500 mg/kg to the basal diet (designated as, M300, M600, M900, M1200 and M1500, respectively). Triplicate groups of shrimp (initial body weight, 0.55±0.01 g) were fed one of the experimental diets for 42 days. The growth performance of shrimp in M0- group was significantly lower when compared to that of shrimp in M0, M1200 and M1500 groups. Feed efficiency was significantly improved in M1200 and M1500 groups when compared to the M0 and M0- groups. GPx activity was significantly higher in M1200 and M1500 groups compared to that in M0 and M0- groups. Therefore, a practical diet (over 240 mg/kg) meets the minimum MI requirements of Pacific white shrimp. However, the optimum dietary MI level would be potentially above 1,200 mg/kg for better feed utilization efficiency and antioxidant capacity of Pacific white shrimp.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.3
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• pp.287-292
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• 2021

This study was conducted to evaluate the effects of dietary supplementation with shrimp soluble extract (SSE) on growth performance, feed utilization, innate immunity and digestibility of Pacific white shrimp Litopenaeus vannamei. A basal diet (Con) was formulated and three other diets were prepared with SSE supplementation at different levels of 1, 2 and 4% (designated as SSE1, SSE2 and SSE4, respectively). Triplicate groups of shrimp (1.20±0.01 g) were fed one of the experimental diets for 6 weeks. At the end of the feeding trial, growth performance and feed utilization of the shrimp were significantly improved by dietary supplementation of SSE4 compared to those of shrimp fed the Con diet. Shrimp fed SSE4 diet had significantly higher phagocytic activity than shrimp fed the Con diet. Dietary supplementation of SSE improved the protein and dry matter digestibility of shrimp. These results indicate that SSE can be used as a functional additive in the diets for Pacific white shrimp.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.6
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• pp.909-917
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• 2020

This study was conducted to evaluate dietary supplementation of Sargassum horneri (SH) meal on growth performance, feed utilization, innate immunity, antioxidant capacity and disease resistance of Pacific white shrimp. The diets were added with graded levels of SH meal by 0, 0.5, 1, 2, 4 and 8% (designated as Con, SH0.5, SH1, SH2, SH4 and SH8, respectively). Quadruplicate groups of shrimp were hand-fed with one of the diets five times daily for 39 days. The innate immunity and antioxidant capacity of shrimp were significantly improved by the dietary SH supplementation. The cumulative survival of shrimp exposed to Vibrio parahaemolyticus in a challenge was higher in shrimp group fed SH diets, except for SH8, than that of shrimp fed the control diet. Growth performance and feed utilization of the shrimp were significantly decreased with the dietary SH inclusions except for 0.5%. Results indicated that dietary SH meal could be used as a functional supplement for improvements in innate immunity, antioxidant capacity and disease resistance in Pacific white shrimp. The suggested dietary inclusion level of dried SH is approximately 0.5% for the shrimp.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.6
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• pp.900-908
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• 2020

This study was conducted to partially replace fish meal with black soldier fly (BSF) larvae or mealworm (MW) larvae in the diet for Pacific white shrimp Litopenaeus vannamei. A tuna by-product meal (27%) was used as the protein source in a control (Con) diet, which was replaced with 20%, 40%, or 60% BSF (designated as BSF20, BSF40, and BSF60, respectively), or MW (MW20, MW40, and MW60, respectively). The shrimp (average body weight, 0.09 g) were randomly stocked in 28 acrylic tanks and quadruplicate groups were fed one of the experimental diets six times daily. After 57 days of the feeding trial, growth and feed efficiency were significantly higher in shrimp that were fed the BSF40 and BSF60 diets than those in shrimp fed the Con diet. Phenoloxidase, superoxide dismutase, glutathione peroxidase and gene expression of crustin were significantly higher in shrimp fed BSF or MW diets than those in shrimp fed the Con diet. The results indicate that BSF or MW could be used as a fish meal replacement or as a functional protein source in diets and can help improve the growth, feed utilization, innate immunity and antioxidant capacity of Pacific white shrimp.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.886-893
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• 2022

This study was conducted to evaluate the effects of dietary silymarin supplementation on the growth performance, feed utilization, innate immunity and antioxidant capacity of Pacific white shrimp Litopenaeus vannamei. Four experimental diets were formulated to contain 0, 0.025, 0.05 and 0.1% silymarin (designated as Con, S0025, S005 and S01, respectively). Triplicate groups of shrimp (initial body weight: 0.70 g) were fed each of the diets for 6 weeks. After the feeding trial, weight gain and specific growth rate were significantly higher in silymarin-supplemented groups compared to Con group. Dietary silymarin significantly enhanced protein efficiency ratio of S01 group and reduced feed conversion ratio of S005 and S01 groups. Phenoloxidase and anti-protease activities were significantly higher in S01 group compared to Con group. Glutathione peroxidase and catalase activities were significantly higher in silymarin-supplemented groups compared to those of Con group. The results of this study indicate that dietary silymarin could improve the growth performance, feed utilization, innate immunity and antioxidant capacity of Pacific white shrimp. The optimum level of silymarin in diet for Pacific white shrimp is suggested to be ≥0.025%.

• Fisheries and Aquatic Sciences
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• v.27 no.7
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• pp.447-455
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• 2024

This study was conducted to investigate the effects of feeding Artemia nauplii enriched with poly-β-hydroxybutyrate (PHB) on Pacific white shrimp (Penaeus vannamei) post-larvae. A total 900 shrimp (initial average body weight: 2.50 ± 0.01 mg) were randomly distributed into 9 acrylic tanks (96 L) in triplicate groups. The Artemia reared in 0%, 0.25% and 0.50% PHB dissolved water (designated as Con, PHB25 and PHB50, respectively) were fed to the shrimp post-larvae for 14 days. The growth performance of shrimp was significantly higher in PHB25 and PHB50 groups than those in Con group. Survival was not significantly different among all the groups. Relative gene expressions of trypsin and amylase were significantly upregulated in PHB25 group than those of Con group. Relative gene expression of chymotrypsin was significantly upregulated in PHB25 and PHB50 groups compared to Con group. Relative gene expression of insulin-like growth factor-I was significantly upregulated in PHB25 group than in Con group. Relative gene expression of insulin-like growth factor-binding protein was significantly upregulated in both PHB25 and PHB50 groups than that of Con group. Relative expression of prophenoloxidase gene was significantly upregulated in PHB25 and PHB50 groups as compared to Con group. Relative expression of penaeidin-3a gene was significantly upregulated in PHB50 group as compared to Con group. This study demonstrated that PHB, as a functional nutritional enrichment for Artemia, improves the growth, digestibility and immunity of shrimp post-larvae.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.5
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• pp.624-633
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• 2021

This study was conducted to determine the supplemental effects of two insect meals, mealworm (MW) and black soldier fly (BSF), with high or low lipid levels in diets, on Pacific white shrimp Litopenaeus vannamei. Sardine and tuna by-product meals were used as the fish meal source in a control (Con) diet. The fish meals were replaced with MW, defatted MW (deMW), BSF or defatted BSF (deBSF), respectively. The shrimp (body weight: 0.47 g) were stocked into 20 acryl tanks (215 L) and fed the diets six times a day. After 45 days of the feeding trial, the shrimp that were fed insect meals had significantly higher phenoloxidase and superoxide dismutase activities than the shrimp fed Con diet. The gene expressions of prophenoloxidase, crustin and penaeidine-3c in shrimp hepatopancrease were also higher in shrimp that were fed the insect diets, regardless of defatting than those in shirmp that were fed Con diet. The survival against Vibrio parahaemolyticus was higher in shrimp that were fed the diets containing defatted insect meals than in shrimp that were fed Con diet. These results indicate that MW and BSF, regardless of lipid levels, could be good protein sources for the enhancement of innate immunity and anti-oxidant capacity of the shrimp.

• Fisheries and Aquatic Sciences
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• v.21 no.10
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• pp.30.1-30.6
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• 2018

A study of three feeding trials was conducted to investigate the dietary protein requirements of Pacific white shrimp (Litopenaeus vannamei) at three different growth stages. Six experimental diets were formulated to include increasing protein levels of 25, 30, 35, 40, 45, and 50% (designated as P25, P30, P35, P40, P45, and P50, respectively) for three feeding trials. The three feeding trials were conducted in different-sized shrimp at 0.65 g (trial 1), 4.80 g (trial 2), and 10.5 g (trial 3). Triplicate groups of shrimp were fed one of the experimental diets for 36, 42, and 48 days in trials 1, 2, and 3, respectively. In trial 1, the growth performance was not affected by the dietary protein levels. However, protein efficiency ratio was significantly higher in P30 diet compared to P40, P45, and P50 diets. In trial 2, growth rate was significantly higher in P35 diet than in P25 diet. In trial 3, the lowest growth performance was obtained in P25 diet which significantly differed from that of other experimental diets. Broken line analysis of growth data indicates that the optimal dietary level of crude protein is 34.5, 35.6, and 32.2% for small-, medium-, and large-sized (juvenile, sub-adult, and adult stages) Pacific white shrimp, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.1
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• pp.8-14
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• 2017

A feeding trial was conducted to evaluate the effect of dietary supplementation with fermented soybean meal by Bacillus subtilis (BFSBM) on growth performance, feed utilization, innate immunity, water quality, and disease resistance of Litopenaeus vannamei. A basal fish meal-based diet was regarded as a control and two other diets were prepared by replacing 30% fish meal with either soybean meal (SBM) or BFSBM. Triplicate groups of shrimp ($0.80{\pm}0.010g$) were fed one of the experimental diets for 6 weeks. No differences were found in final body weight, feed conversion ratio, or survival among all dietary treatments after the feeding trial. Shrimp fed the BFSBM diet had significantly higher phagocytic and phenoloxidase activities than those of shrimp fed the SBM diet. Total ammonia concentrations in culture water during a zero water exchange test tended to decrease in tanks where BFSBM diet was provided. Disease resistance of shrimp to Vibrio harveyi tended to increase in the BFSBM group during 14 days of challenge compared to that in the control (CON) and SBM groups. These results show that dietary supplementation with BFSBM can enhance the innate immunity of Pacific white shrimp and replace at least 30% of dietary fish meal.

• Journal of Microbiology and Biotechnology
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• v.34 no.8
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• pp.1705-1710
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• 2024

Plastic waste has emerged as a major environmental concern in recent years. As plastic waste discharged into the marine environment, it undergoes a breakdown process, eventually accumulating in aquatic organisms in the form of microplastics (MPs). To date, reduced food intake, nutritional absorption, and impaired immune system are known adverse effects of MPs-exposed aquatic organisms. This study aims to investigate whether MP exposure accelerated white spot syndrome virus (WSSV) infection in Pacific white shrimp (Penaeus vannamei) via laboratory tests. Briefly, experimental shrimp were divided into four groups; WSSV (group 1); MP (group 2); WSSV + MP (group 3); and Control (group 4). No mortality was observed in group 2, group 4, and even in group 1. However, group 3 showed a cumulative mortality of 50% during the experimental period. The PCR assay results showed no WSSV in the other three groups (groups 1, 2, and 4), but the dead and alive shrimp collected from group 3 were confirmed to be infected with the virus. Histopathological examination revealed normal structures in the hepatopancreas, gill, and muscle tissues of group 4, whereas numerous abnormally shaped nuclei were detected in the gill tissue of group 2. Moreover, group 1 showed minor WSSV-related lesions with few basophilic inclusion bodies in the gills, interestingly, group 3 exhibited severe lesions with numerous basophilic inclusion bodies in the gills. In conclusion, this study confirmed the correlation between the viral disease of shrimp and MPs, which can cause significant economic losses to the shrimp aquaculture industry.