• 한국어병학회지
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• 제36권2호
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• pp.361-368
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• 2023

Juveniles of the white leg shrimp Litopenaeus vannamei (Weight 0.18±0.08 g) were exposed to nitrite-N at 0, 25, 50, 100, 200 and 400 mg/L for 72 hours, and the lethal concentration, heamolymph and genes regulation were evaluated. The lethal concentration 50 (LC₅₀) of L. vannamei exposed to nitrite-N was 141.2 mg/L at 25℃ and 33 psu. In Total protein, total cholesterol, and BUN in heamolymph temporarily increased after the start of the experiment and then stabilized, but glucose, an indicator of stress, decreased over time in the entire experimental group, and creatines, an indicator of tissue damage, decreased with nitrite concentration until the first 12 hours. The genes of immune-related showed that masquerade-like serine proteinase(Mas) increased at 50 and 400 ppm for 24 hours, and then gradually decreased depending on concentration. In the case of prophenoloxidase, it was highest at 400 ppm for 40 hours, and other genes(Ras-related nuclear protein, Masquerade-like serine proteinase, proPO-activating enzyme) showed a response for 48 hours and then gradually decreased. The results of this study indicate that exposure to nitrite can affect the survival and hematological physiology of L. vannamei.

• 환경생물
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• 제37권2호
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• pp.136-143
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• 2019

안정된 바이오플락 사육수에는 대량의 미생물들이 존재하고 있으며 사육수온이 높아 재사용이 가능할 경우 빠른 수질안정화 및 에너지 절약을 할 수 있다. 바이오플락 사육수 내 부유하고 있는 자가 및 타가 영양세균은 호기성과 혐기성 세균을 모두 포함하고 있어 탄소원을 넣고 산소를 공급하지 않는 혐기성 상태로 만들면 탈질과정이 가능하다. 본 연구에서 바이오플락 탈질수의 특성은 암모니아(6.9 mg L^-1), 아질산(0.3 mg L^-1), 질산농도(9.2 mg L^-1), 높은 pH(8.42), alkalinity (590 mg L^-1)였으며 이 탈질수를 첨가한 사육수의 물리적 환경 변화가 어린새우의 생존 및 생리적 특성에 미치는 영향을 조사하였다. 그 결과 탈질수를 100% 사용하여도 생존율의 변화를 보이지 않았으나 혈림프를 포함한 체액 분석결과 탈질수 혼합에 의한 조직손상 및 스트레스 지표인 크레아틴, 혈중 요소성 질소의 증가가 관찰되었고 탈질수 혼합비율이 높을수록 새우 체내 이온(Na⁺, K⁺, Cl^-)의 농도가 유의적으로 감소하여 향후 삼투압조절에 영향을 미칠 수 있는 것으로 나타남에 따라 탈질수를 일정비율로(50% 미만) 혼합하여 사용하는 것이 바람직한 것으로 사료된다.

• 한국어병학회지
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• 제33권1호
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• pp.45-53
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• 2020

Doxycycline is a semi-synthetic broad-spectrum antibiotic, and it has been used to get rid of bacteria in animals and humans. The use of antibiotics has greatly contributed to the aquaculture production although its misuse sometimes presents public health problems. This study was performed to investigate the toxic effects of doxycycline on whiteleg shrimp (Litopenaeus vannamei) administered for possible infection treatments. The shrimp were allocated into four groups and doxycycline was fed three times a day for 7 days at 0, 20, 50 and 100 mg/kg to each group. After 24 hr following the 7-day treatment, hemolymph and hepatopancreas were used for blood and biochemical analysis: Total hemocyte counts, Total protein, Total cholesterol, Gluscose, Glutamic pyruvic transaminase, Glutamic oxaloacetic transaminase, Glutathione peroxidase, Superoxide dismutase, Glutathione-s-transferases, Total antioxidant capacity colorimetric and Acid phosphatase. In addition, histopathological examination was performed on the hepatopancreas and muscle. It was observed that body weight gain was significantly retarded in 100 mg/kg doxycycline group. Doxycycline was found to induce biochemical or functional disorders at 100 mg/kg as observed many of the blood and biochemical parameters were significantly reduced. In conclusion, it was judged that there will be no major toxicity problems with doxycycline when used for shrimp aquaculture at regular doses.

• 한국수산과학회지
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• 제50권1호
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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.

• 한국수산과학회지
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• 제45권6호
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• pp.659-665
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• 2012

A 4-week feeding experiment was conducted with juvenile white shrimp Litopenaeus vannamei to compare the growth of shrimp fed different protein sources: fish meal (FM) and soybean meal (SM). By the end of the experiment, the shrimp grew to $4.50{\pm}0.82$ g (FM) and $4.73{\pm}0.95$ g (SM). The food and protein conversion rates were significant (P<0.05), while other factors did not differ significantly. The survival rate of shrimp fed FM and SM was $96.44{\pm}2.04%$ and $97.33{\pm}1.89%$, respectively. The proximate compositions of the entire body and edible part of the shrimp were similar between FM and SM, except for crude protein. The total amino acid levels were slightly lower in SM than FM, but the difference was not significant. During the experiment, the total ammonia, nitrate, and nitrite concentrations increased continuously in both groups and were slightly higher in SM than FM. In conclusion, soybean meal as a substitute for fish meal results in satisfactory growth and survival of white shrimp.

• 한국수산과학회지
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• 제54권5호
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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.

• 한국환경과학회지
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• 제28권1호
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• pp.1-6
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• 2019

Ptecticus tenebriferwas incorporated to partially or totally replace the diets of juvenile white shrimp (Litopenaeus vannamei). Experimental groups of shrimp with an average initial body weight of $0.014{\pm}0.001g$ were fed each of the 5 diets formulated to include 0, 25, 50, 75, and 100% (C, T25, T50, T75, and T100, respectively) of Ptecticus tenebriferpowder substituted for commercial feed. After eight weeks of feeding trials, juvenile shrimp fed with diets T25 and T50 showed higher live weight gain ($2.298{\pm}0.405$ and $2.539{\pm}0.406$, respectively), and a better feed conversion ratio ($1.389{\pm}0.246$ and $1.536{\pm}0.246$, respectively) compared to those of shrimp fed a control diet. Survival rate was 98% in all experimental groups except for the T75 group ($66.67{\pm}57.73%$ survival). The levels of immune markers such as beta-glucan binding protein, prophenoloxidase, and crustin associated with the cellular and humoral immunity of shrimp were found to be higher in 25% and 50% commercial feed replacement groups. A reduction in total nitrogen, nitrite nitrogen, and ammonia levels was greater in T25 and T50 rather than in T75 and T100. These results clearly indicate that replacement of feed with 25 to 50% Ptecticus tenebriferpowder in juvenile white shrimp diet was optimal in promoting the growth performance of shrimp without any adverse effects.

• 한국수산과학회지
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• 제54권5호
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• pp.761-768
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• 2021

This study was carried out to identify an effective method to acclimate low-salinity (4 psu) bred Litopenaeus vannamei (mean body weight 16±3.3 g) to sea water. The fast acclimation group (FA) was directly exposed to filtered sea water (32 psu) while the slow acclimation group (SA) was exposed to a slow increase in salinity. Shrimps were sampled at 0, 1, 3, 6, 12, 24 and 48 h for plasma analyses. The plasma components between experimental groups did not show significant differences. The hemolymph osmolality (HO) in FA increased significantly after 1 h (P<0.05), while in SA it started to increase slowly only at 24 h and reached a similar level to that of FA at 48 h. The levels of Na⁺ and Mg²⁺ ions were significantly different between the two treatments (P<0.05), but there was no significant difference in Ca²⁺ ion levels. We found that the different methods of acclimation of L. vannamei to sea water do not affect the plasma components significantly, but lead to changes in the HO and ion levels, it is considerable to acclimate gradually for at least two days.

• 한국수산과학회지
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• 제53권6호
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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.

• 한국수산과학회지
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• 제53권6호
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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.