• 한국양식학회:학술대회논문집
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• 한국양식학회 2006년도 수산관련학회 공동학술대회 발표요지집
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• pp.330-331
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• 2006

• 한국양식학회:학술대회논문집
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• 한국양식학회 2006년도 수산관련학회 공동학술대회 발표요지집
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• pp.328-329
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• 2006

• 한국수산과학회지
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• 제32권1호
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• pp.18-21
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• 1999

본 연구는 넙치 치어 (평균체중 1.6g)의 적정 사료 공급 횟수를 조사하여 경제적이고 수질오염원을 줄이기 위한 먹이 공급 체계를 제시하기 위해 수행되었다. 양어가들이 주로 사용하고 있는 건조 pellet 형태의 상품사료와 습사료 (moist pellet, MP)를 제조하여 각 실험수조 (50$\iota$)에 40마리씩 3 (diet)$\times$5 (feeding regimen)$\times$3 (replication) factorial design으로 수용하여 사육 실험 하였다. 사료 공급은 1일 4회 (06:00, 10:00, 14:00, 18:00), 1일 3회 (06:00, 12:00, 18:00), 1일 2회 (06:00, 18:00), 1일 1회 (06:00) 및 2일 1회 (09:00)로 설정하였다. 3 종류의 실험사료로 넙치 치어를 30일간 사육 실험한 결과, 모든 사료에서 공급 횟수가 낮아질수록 일일사료섭취량은 감소하였으며 (P<0.05),사료 공급 횟수가 동일할 때에도 사료 종류에 따라 사료 섭취량이 달라지는 경향을 보였고, 특히 MP 사료가 다른 두 사료보다 그 섭취량이 낮았다. 성장은 세 사료 모두 1일 3회 공급구는 1일 4회 공급구와 유의적인 차이가 없었으므로 1.6$\~$4g의 넙치 치어의 적정 사료 공급 횟수는 1일 3회가 적당할 것으로 판단된다. 따라서 사료를 불필요하게 자주 공급할 필요가 없을 것으로 보이며, 과다한 사료 공급은 경제적으로나 인력적인 면에서 불이익이 초래될 것으로 판단된다.

• 한국양식학회지
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• 제19권3호
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• pp.197-204
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• 2006

넙치 치어 3 cm와 5 cm 그룹을 이용하여 Philasterides dicentrarchi에 대한 병원성과 감염경로를 조사하였다. 소형수조에서 넙치치어에 스쿠티카충을 인위감염시킨 결과 3 cm 그룹인 경우 접종 4일 후에 40%가 감염되었으며, 24일 후에는 감염률이 90.1%로 대부분의 실험어가 감염되었다. 5 cm 그룹은 3 cm그룹에 비해서 초기 감염률이 현저히 낮았다. 접종 8일 후에 최초로 20%의 감염률을 보였으며 16일 후에도 42%로 완만한 속도로 감염률이 증가하였다. 그러나 그 이후에는 감염률이 급격히 증가하여 24일 후에는 81%에 달했다. 반면에 스쿠티카충을 접종시키지 않은 대조구에서는 스쿠티카충이 감염되지 않았다. 인위감염시킨 스쿠티카충의 어체내 침투는 몇 가지 경로로 이루어졌는데, 지느러미 연조막에 감염된 후 지느러미 조직과 근육에 침투하는 경로, 주둥이 부위의 부드러운 표피를 통하여 감염 된 후 두부 골격과 근육 결을 따라 안구와 뇌로 침투하는 경로, 꼬리지느러미를 통해서 미병부에 침투한 후 척수에 도달하고, 척수를 따라 뇌에 침투하는 경로 등이었다. 이외에도 복강에 침투하는 경우도 있었는데, 항문주위에 다량으로 증식하며 조직을 괴사시킨 후 복강으로 침투하였다. 치명적인 피해를 입히는 뇌 침투는 3cm그룹은 충 접종 후 14일 만에, 5cm그룹은 20일 만에 각각 확인되어 어체가 작을수록 빨리 이루어졌다.

• Environmental Analysis Health and Toxicology
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• 제22권1호
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• pp.83-90
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• 2007

This study was investigated the effort of growth and gonadal development in olive flounder, Paralichthys olivaceus exposed to PCBs Effluent Allowance Concentration, 3.0 ppb in Korea. Total length, body weight and weight gam of fish were no significant differences between two treatments (control: T.L.-110.0 mm, T.W.-9.61 g: treatment: T.L.-112.8 mm, T.W.-9.68 g), however, weight gain of fish unexposed to PCBs wat observed to increase gradually from 100 days after hatching (30 days after treatment). In the indifferentiated gonad to the juvenile stage, the differentiation of the ovary occured at 60 days after hatching (20 days after treatment) and that of the testis occured at 70 days after hatching (30 days after treatment) in two groups. In the ovary, the oogonia and ovarian lamellar appeared 130 days after hatching (50 days after treatment). The spermatogonia and resticular lobule of the testis were observed at 130 days after hatching (50 days after treatment). Testicular cyst appeared 140 days after hatching (60 days After treatment). There was no difference on the development of ovary and testis. There was no obvious difference of sex ratios. Therefore, These results considerate that PCBs have any effect for growth and gonadal development, but a little act for early growth in olive flounder.

• 한국어병학회지
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• 제16권3호
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• pp.183-191
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• 2003

본 연구는 넙치의 수온 스트레스에 대한 사료첨가제(미역 5%, 미역 10%, 어보산 0.5%, 고추냉이 잎 2%, 고추냉이 줄기 2%)의 영향을 혈액학적, 면역학적 측면과 Edwardsiella tarda를 사용하여 질병에 대한 저항성으로서 평가하였다. 혈장의 글루코즈와 콜티졸 농도는 1차 수온 변동 후 대조구에 비하여 미역 5%와 고추냉이잎 2% 첨가구에서 유의적으로 낮게 나타났다(P<0.05). 1차 수온 변동 후 혈장 라이소자임 활성과 E. tarda의 공격 시험 후 생존율은 미역 5% 첨가구에서 대조구에 비하여 유의적으로 높게 나타났다(P<0.05). 본 실험 결과 미역 5% 첨가 사료 투여는 넙치의 스트레스 상태에서 질병 감염에 대한 저항성을 높일 수 있을 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제19권5호
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• pp.720-726
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• 2006

In an attempt to develop an artificial diet for growing olive flounder (Paralichthys olivaceus), weight gain, feed utilization and nutrient retention were investigated in fish fed moist (MP), semi-moist (SMP) and extruded pellets (EP). Excretion of nitrogen and phosphorus was also estimated based on their whole body gain and intake. EP and MP composed of raw fish and SMP made of formulated powder feed with water were prepared to have the same energy contents on a dry matter basis. A total of 240 fish with an average initial weight of 120 g were randomly distributed to each (20 fish/tank) of 12 circular plastic tanks (4 tanks/treatment) and fed experimental diets for 8 weeks. Fish groups fed EP (209 g) or SMP (209 g) recorded higher final weight than those fed MP (176 g), while dry feed consumption was highest in SMP groups (106 g), followed by MP (71 g) and EP groups (62 g). As a consequence, fish groups fed EP showed much lower feed conversion ratio than the other two groups. Protein efficiency ratio was also significantly higher in fish groups fed EP (2.55) than in those fed MP (1.44) and SMP (1.31). Fish groups fed EP, which showed the highest nitrogen retention of 43.9%, resulted in the lowest excretion of nitrogen of 35.5 g per kg gain. Also, the lowest phosphorus excretion of 6.0 g per kg gain was found in the EP groups with the highest P retention (37.0%) among treatments. Although the EP groups had the lowest dietary energy intake, they retained the highest energy in the whole body among treatments. The present results showed that EP could be more advantageous than MP or SMP in terms of growth, feed utilization and excretion of nitrogen and phosphorus for olive flounder.

• Fisheries and Aquatic Sciences
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• 제13권4호
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• pp.284-293
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• 2010

To reduce anti-nutritional factors in plant protein sources for fish meal replacement in fish feeds, cottonseed and soybean meal (CS) were fermented with Aspergillus oryzae. A feeding trial was conducted to verify the effects of fermented CS (FCS) with phytase supplementation on gossypol detoxification, phosphorus digestibility, antioxidant activity, and growth performance of juvenile olive flounder over 10 weeks. Four diets were formulated to replace 0, 30, or 40% fish meal protein with CS or FCS (designated as CS0, CS30, FCS30P, and FCS40P). Phytase (1,000 FTU/kg) was added to FCS30P and FCS40P. The microbial fermentation significantly increased dietary total polyphenols and consequently led to higher DPPH radical-scavenging activities in fish feed and fish tissue. Dietary and liver gossypol concentrations were dramatically decreased by the fermentation process. Phosphorus digestibility was significantly increased in fish fed the FCS40P diet. However, growth performance decreased in fish fed FCS diets. This study demonstrates that the fermentation process and phytase supplementation can improve the phosphorus availability of plant protein sources in fish. The fermentation of CS by A. oryzae could increase antioxidant activities in feed and fish and effectively degrade toxic gossypol in cottonseed meal.

• 한국수산과학회지
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• 제51권2호
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• pp.157-162
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• 2018

A feeding trial was conducted to investigate the effects of supplementation with four phosphorus (P) additives [mono-calcium phosphate (MCP), dicalcium phosphate (DCP), tricalcium phosphate (TCP) and magnesium hydrogen phosphate (MHP)] on the growth, feed utilization and whole body mineral composition of juvenile olive flounders Paralichthys olivaceus. A basal diet without P supplementation was prepared as a negative control and four supplemental P sources were added at a level of 2%. Triplicate groups of fish (initial mean body weight 11 g) were fed one of the experimental diets to apparent satiation twice a day, at 08:30 and 18:00 for 10 weeks. The final body weights of fish fed the experimental diets ranged from 29.4 g (DCP) to 34.2 g (MCP) and did not differ significantly (P>0.05) among treatments. Similar tendencies were found for all parameters including weight gain (%), specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER), feed intake (FI) and survival rate (SR). The hematocrit (%), hemoglobin (g/dL), serum inorganic P and whole body mineral composition did not differ significantly different (P>0.05) among the treatments. Therefore, dietary P addition is not necessary for juvenile olive flounder fed a fish meal-based diet.

• Fisheries and Aquatic Sciences
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• 제7권4호
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• pp.192-203
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• 2004

The effects of temperatures, starvation, and kind of foods on growth, RNA/DNA ratio and protein contents during metamorphosis and early juvenile stage of olive flounder (Paralichthys olivaceus) were examined. During metamorphosis, warm-acclimated fish showed higher RNA and DNA content than those of the cold-acclimated fish, excepting H stage (28 DAH) at which the ratio was higher at cold temperature. RNA/DNA ratio during metamorphosis showed similar values at two temperatures tested. However, after 42 DAH warm-acclimated juveniles had higher DNA content compared with cold-acclimated fish, resulted in marked decreases in RNA/DNA ratios. Higher RNA content at H stage of cold-acclimated fish was consistent with an increase in protein content. Growth of fish rearing at warm temperature was higher than those of fish at cold temperature during all experiments. In starvation experiment, contents of DNA, RNA and protein significantly decreased. Even though there were no significant differences in total length (TL) and body weight between the live mysid-fed and artificial pellet-fed fish at 35 mm TL, both RNA/DNA and protein/DNA ratios of the former group was significantly higher than those of the latter due primarily to lower DNA content of the live mysid-fed group. The results from this study suggest that temperature, starvation and kind of foods should be considered when RNA/DNA ratio applied to assessing the cultured larval and juvenile fish condition.