• Asian-Australasian Journal of Animal Sciences
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• 제21권6호
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• pp.868-872
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• 2008

This experiment was conducted to evaluate the long term effects of dehulled soybean meal (DHSM) as fish meal (FM) replacer in the diet for olive flounder, Paralichthys olivaceus, for 42 wk at a commercial fish farm. The four experimental diets were MP (moist pellet based on raw fish), $DHSM_0$ (fish meal based dry pellet), $DHSM_{30}$ (30% fish meal was replaced by DHSM) and COMD (commercial dry pellet). Fish were fed one of the four diets containing 50% crude protein and 16.7 kJ available energy/kg diet for 42 wk. Fish averaging $3.20{\pm}0.04g$ ($mean{\pm}SD$) were initially distributed to each tank as a group of 6,000 fish reared in a flow-through system. At the end of the experiment, average body weight of fish was $315{\pm}9.3g$ ($mean{\pm}SD$) ). Weight gain (WG) and feed efficiency (FE) of fish fed MP, DHSM0 and DHSM30 showed no significant difference among the diet treatments. However, WG and FE of fish fed MP were significantly higher than those of fish fed COMD (p<0.05). Specific growth rate (SGR), protein efficiency ratio (PER) and survival of fish fed all diets were not significantly different among the dietary treatments. Therefore, these results indicate that DHSM could replace up to 30% white fish meal with amino acid supplementation in olive flounder diets for long-term feeding practice at the commercial farm.

• Fisheries and Aquatic Sciences
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• 제11권1호
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• pp.15-22
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• 2008

Excessive growth of phytoplankton is a common and severe problem in intensively farmed pangasiid catfish (Pangasius hypophthalmus) culture ponds. It can lead to cyanobacterial blooms, reduced fish growth, bad-tasting fish flesh, and lower market demand. To investigate how to manage undesirable phytoplankton growth, we evaluated three stocking strategies in nine rural fishponds (0.020-0.022 ha) owned by various farmers: a pangasiid catfish mono culture (treatment 1, $T_1$), and pangasiid catfish-silver carp (Hypophthalmichthys molitrix) polycultures at two stocking ratios of 1:1 (treatment 2, $T_2$) and 2:1 (treatment 3, $T_3$). The total density of all ponds was approximately 30,000 fishes/ha. Monoculture ($T_1$) resulted in significantly higher (p < 0.05) nutrient levels (nitrate and phosphate) in ponds than did polyculture ($T_2$ and $T_3$). Nutrient loads increased with culture time, resulting in increased growth of phytoplankton, including Cyanophyceae (9 genera), Chlorophyceae (15 genera), Bacillariophyceae (8 genera), and Euglenophyceae (3 genera). The introduction of silver carp as a co-species helped to regulate phytoplankton growth and to improve the water quality of pangasiid catfish culture ponds.

• 수산해양기술연구
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• 제26권4호
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• pp.309-316
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• 1990

1986년 5월부터 1988년 4월까지 정기 채집한 545 개체와 정점 채집한 525개체등 합계 1,070개체의 이석을 적출하여 연령 형질로서 사용했다. 이석 연근의 투명대와 불투명대의 관찰 결과, 투명대 형성개시시기는 5월이며, 불투명대 개시시기는 1월이었다. 투명대와 불투명대는 년1회 형성되므로 투명대 외연을 연령표시로서 이용했다. 이석 반경과 표준체장의 관계식으로부터 각륜 형성시의 체장을 역산했다. Lee 현상은 보이지 않았으며, 이석반경과 표준체장은 곡선개계를 나타냈다. 각 연령 형성시의 계산체장은 이용하여 von Bertalanffy 성장식을 다음과 같이 구했다. Male ;Lt=376.9{1-exp[-0.303(t-0.202)]} Female ;Lt=255.7{1-exp[-0.505(t-0.149)]} 여기서, Lt는 표준체장(mm)이고, t는 연령이다.

• Journal of Microbiology and Biotechnology
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• 제33권10호
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• pp.1390-1401
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• 2023

In this study, a 12-week feeding experiment was conducted to characterize the effects of exogenous α-amylase on the growth, feed utilization, digestibility, plasma α-amylase activity, feed degradation rate, and fecal particle size of olive flounder (Paralichthys olivaceus). Diet was supplemented with 0 (AA₀; control), 100 (AA₁₀₀), 200 (AA₂₀₀), or 400 (AA₄₀₀) mg/kg of α-amylase, respectively. Fish (273.1 ± 2.3 g) were stocked into 12 tanks (25 fish/1,000-L tank) and 3 tanks were randomly selected for each diet group. As a result, α-amylase was found to have no significant effects (p ≥ 0.05) on the growth, feed utilization parameters, and whole-body proximate compositions. α-Amylase-treated fish exhibited only a significant increase in the apparent digestibility coefficient of carbohydrates compared to the controls. In addition, in vitro analyses revealed that α-amylase dose-dependently increased (p < 0.05) the feed degradation rate, while photographs of the intestinal content after 2, 4, and 8 h of feeding demonstrated an improved degradation rate in the α-amylase-treated groups. Plasma α-amylase content was higher in the AA₂₀₀ and AA₄₀₀ groups, whereas the control group produced significantly larger-sized fecal particles (90% size class) than these two groups. In the intestine, no changes were observed in the expression levels of the immune-related TNF-α, IL-1β, IL-2, immunoglobulin-M, HSP-70, lysozyme, and amylase alpha-2A. However, growth-related genes IGF-1, IGF-2, TGF-β3, and growth hormone genes were upregulated in muscle tissues. Collectively, exogenous α-amylase has positive roles in the modulation of the digestibility coefficient, blood α-amylase concentration, growth-related gene expression, and diet degradation for improved digestion in olive flounder.

• 수산해양기술연구
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• 제59권4호
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• pp.387-398
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• 2023

Conventional aquaculture faces declining productivity, shifting to recirculating aquaculture system (RAS), known for minimizing water usage and maintaining consistent water temperatures for year-round fish growth. Rainbow trout (Oncorhynchus mykiss), a globally important cold-water species and the third most farmed fish in inland waters of Korea, valued for its fecundity and rapid growth. Dissolved oxygen, an important environmental factor affecting fish production and economics, highlights the need for smart aquaculture practices. Since 2018, the rise of intelligent aquaculture platforms, incorporating information and communications technology (ICT), emphasizes the essential role of RAS implementation. This eight-week study aimed to determine the optimal dissolved oxygen concentration for rainbow trout in RAS, utilizing a device for continuous monitoring, control and record. Dissolved oxygen concentrations were set at 5-6 mg/L, 9-10 mg/L, 14-15 mg/L and 17-18 mg/L. The growth rate significantly decreased at 5-6 mg/L, with no significant differences in other experimental groups. In hematological analysis, growth hormone (GH) was significantly highest at 5-6 mg/L, followed by 9-10 mg/L while Insulin-like growth factor-1 (IGF-1) was significantly lowest at 5-6 mg/L. In conclusion, the optimal dissolved oxygen concentration for rainbow trout in RAS is approximately 9-10 mg/L. Higher concentrations do not contribute to further growth or profitability.

• 한국양식학회지
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• 제18권1호
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• pp.37-44
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• 2005

해산어류의 담수순화 양식을 위한 기초자료를 얻고자, 감성돔을 재료로 하여 담수와 해수에서 90일간 사육하였을 때, 어체의 생리상태를 스트레스, 삼투압조절, 성장 및 생존율 측면에 서 조사 비교하였다. 스트레스 측면에서 담수돔과 해수돔의 혈장 cortisol농도의 경우 60일째까지 유의한 차이가 없었으며, 실험종료시에는 각각 12.6$\pm$5.0 ng/ml, 4.5$\pm$2.9 ng/ml로 담수돔이 해수돔보다 높았지만 안정시의 농노에 포함되는 것으로 나타났다. 삼투압조절 측면에서 담수돔과 해수돔의 삼투질농도의 범위는 각각 346.7$\pm$4.6$\~$356.5$\pm$2.1 mOsm/kg, 350.0$\pm$2.0$\~$351.0$\pm$2.6 mOsm/kg으로 차이가 나타나지 않았으며, 또한 아가미 조직의 손상이나 세포의 괴사도 관찰되지 않았다. 성장 및 생존율 측면에서 실험종료시 담수돔과 해수돔의 전장은 각각 17.0$\pm$1.3 cm, 16.1$\pm$0.8, 체중은 각각 88.2$\pm$22.0 g, 69.4$\pm$11.8 g, 생존율은 각각 $80.2\%$, $73.7\%$로 담수돔에서 높게 나타났으나 유의한 차이는 인정되지 않았다. 또한 증중률 등의 성장관련 요인과 체성분의 조성면에서도 담수돔과 해수돔간의 차이가 없는 것으로 나타났다.

• 수산해양교육연구
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• 제27권2호
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• pp.390-398
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• 2015

A feeding experiment was conducted to determine the use of distillers dried grain (DDG) as a partial replacement for fish meal in the diet for juvenile rockfish, Sebastes schlegeli. Four iso-nitrogenous (50% crude protein) and iso-caloric (4.3 kcal/g) diets (designated as DDG0, DDG7, DDG14, and DDG21) were formulated to contain 0, 7, 14, and 21% DDG. Triplicate groups of juvenile rockfish (initial body weight, $10.2{\pm}0.2g$) were fed one of the experimental diets to visual satiety twice a day (09:00 and 17:00) for 8 weeks. At the end of the feeding trial, survival of rockfish was above 97% and not affected by dietary DDG levels (P>0.05). Weight gain, feed efficiency and daily feed intake of juvenile rockfish were significantly decreased with increase of dietary DDG levels (P<0.05). Condition factor, hepatosomatic index and visceralsomatic index of juvenile rockfish were not significantly affected by dietary DDG levels (P>0.05). No significant differences were observed in the contents of moisture, crude protein, crude lipid and ash of the whole body and dorsal muscle in juvenile rockfish fed the experimental diets (P>0.05). Therefore dietary inclusion of DDG as a replacement for fish meal could depress the growth of juvenile rockfish.

• 한국전자통신학회논문지
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• 제15권5호
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• pp.959-966
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• 2020

수산업의 중요성이 커지고 양식 산업이 급성장한 가운데 수산 양식 분야 ICT 융합을 통한 스마트 양식장에 대한 연구가 진행되고 있다. 양식장 현장에서 생육 환경 모니터링이 가능하도록 수중 드론의 구동부, 영상 수집 장치, 자세 안정화를 위한 통합 컨트롤러, 실시간 수중 영상을 통한 드론 조정 및 제어가 가능한 원격 관제 장치를 제안하고 설계, 개발 및 시험을 진행하였다. 수중 드론 활용을 통해 양식 산업에서 문제 되는 인력 수급 및 고비용 작업을 대체 할 수 있으며, 양식 폐사 확률을 줄여 안정적인 양식장 관리가 가능하다.

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.183-189
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• 1994

Two experiments were made. In experiment 1, four diets containing 0, 5, 15 and 25% washed seaweed meal were prepared to study the effects of incorporating seaweed meal instead of equivalent amounts of berseem leaf meal in fish feeds on growth performance and feed utilization of common carp. The results showed that average daily gain (ADG), specific growth rate (SGR%), dry matter (DM) and ether extract (EE) of the carcasses were decreased (p<0.05) with the increasing level of seaweed meal in the feeds. Inclusion of 5% seaweed meal in the diet gave the best feed conversion ratio (FCR) among all diets, however, protein productive value (PPV) and energy utilization (EU) were decreased (p<0.05) with increasing level of seaweed meal in the diet. In experiment 2, washed seaweed meal was either steam cooked or sprayed with NaOH (0.5% or 1% NaOH) and incorporated in the diets at the level of 25% instead of equivalent amount of berseem leaf meal. The results showed that steam cooked seaweed gave the best (p<0.05) growth performance, FCR and protein efficiency ratios, PER and PPV, for other treatments in descending order were NaOH treated seaweed, washed seaweed and unwashed seaweed.

• 한국수산과학회지
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• 제37권3호
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• pp.197-201
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• 2004

Juveniles of parrot fish (Oplegnathus fasciatus) were graded and divided into three groups (mean initial size): Small group $(32.9\pm3.2\;g),$ Large group $(130.1\pm12.3\;g)$ and Ungraded group $(74.8\pm29.8\;g).$ Growth and sex ratio were monitored over 3 years. It was concluded that no production advantage was gained by weight grading. There were no differences when the pooled data from the two graded groups were compared with the ungraded group, although mean weight and survival of the large group were continuously higher than those of other groups until the end of rearing period. The highest percentage of males was found in the large group. These results show that males start growing faster than females long before the size grading.