• 한국수산과학회지
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• 제46권6호
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• pp.769-776
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• 2013

This study evaluated fermented soybean meal (FSM) as a fish meal (FM) replacement and determined the appropriate amount of FSM in juvenile olive flounder diet. Twenty-four aquaria with a flowing-water system were stocked with fish averaging 20.9 g at a density of 25 fish/tank. Five experimental diets were prepared replacing FM with 0, 10, 20, 30, or 40% FSM based on FM protein (designated $FSM_{0}$, $FSM_{10}$, $FSM_{20}$ $FSM_{30}$, and $FSM_{40}$, respectively). Two additional diets were prepared that replaced 30 or 40% of the FM with FSM with added amino acids (methionine and lysine) (designated $FSM_{30+AA}$, and $FSM_{40+AA}$, respectively). Fish (triplicates) were fed one of the eight experimental diets (50% crude protein and 16.7 kJ available energy $g^{-1}$ diet) for 8 weeks. Survival did not differ among the treatments during the feeding experiment. There were no significant differences in weight gain (WG) or specific growth rate (SGR) among the fish fed diets with up to 30% of the FM replaced. However, fish fed $FSM_{40}$ or $FSM_{40+AA}$ had a reduced WG and SGR, as compared to $FSM_0$ (control) (P < 0.05). The feed efficiency and apparent digestibility showed a similar trend (P < 0.05). The proximate composition in the whole body of fish differed only between the control and $FSM_{40}$ for the crude protein level and between the control and $FSM_{30+AA}$ for the crude lipid level. The whole-body amino acid composition did not differ among treatments. No significant differences were found between the diet groups with and without amino acid supplementation, indicating that amino acid supplementation had no effect. The major finding of this study is that fermented soybean meal may replace up to 30% of fish meal without amino acid supplementation for normal growth of juvenile olive flounder.

• 한국환경생물학회:학술대회논문집
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• 한국환경생물학회 2002년도 학술대회
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• pp.141-144
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• 2002

Environmental estrogens are natural or synthetic substances present in the aquatic environment, especially in effluent from sewage treatment. However, the adverse effects of these estrogenic substances on fish reproduction are unknown. Di-2-ethylhexyl phthalate (DEHP) is the most common phthalate, which Ps used as a plasticizer in polyvinylchloride (PVC), and it is widespread in the environment and has been found in aquatic organisms and sediments. Therefore, juvenile common carps (Cyprinus carpio) were exposed to nominal concentrations of 17$\beta$-estradiol (E2) (0.5, 5, 50 $\mu\textrm{g}$/L) and DEHP (10, 100, 500 $\mu\textrm{g}$/L) for 21 days, to determine the adverse reproductive effects of these compounds on plasma vitellogenin (VTG) induction, sex steroid level, and gonad weight. Electrophoresis (SDS-PAGE) revealed that much of VTG was induced in fish exposed to 5 and 50 E$_2$ $\mu\textrm{g}$/L, but none of DEHP exposure showed induction. Enzyme-linked immunosorbent assay (ELISA) revealed that VTG was significantly induced in fish exposed to 5 and 50 E$_2$ $\mu\textrm{g}$/L, and combination of 50 E$_2$ $\mu\textrm{g}$/L with 10 and 500 DEHP $\mu\textrm{g}$/L, but none of DEHP exposure showed induction. Analysis of sex steroid levels in some fish revealed that testosterone (T) was detected in both male and female fish of the control and DEHP exposures, but none of fish exposed to 22 concentrations had detectable testosterone level. On the other hand, E$_2$ exposure induced 17$\beta$-estradiol in plasma of male fish, but there was no induction of 17$\beta$-estradiol in plasma of male fish exposed to DEHP. Comparison of gonadosomatic index (GSI) revealed that maximal E$_2$ exposure inhibited ovarian growth, but maximal DEHP exposure stimulated testicular growth. The results indicated that those comparisons can be a useful bio-indicator for determining adverse reproductive effect of endocrine disrupting chemicals (EDCs).

• 한국수산과학회지
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• 제47권6호
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• pp.824-831
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• 2014

This study was conducted to investigate the effects of fishmeal replacement with acid-concentrated soybean meal (ACSBM) on growth performance, blood biochemistry, and ingredient digestibility in juvenile olive flounder Paralichthys olivaceus. Six experimental diets were formulated to replace fishmeal protein with ACSBM at 0%, 20%, 30%, 40%, 50%, and 60% (designated ACSBM0, ACSBM20, ACSBM30, ACSBM40, ACSBM50, and ACSBM60, respectively). Triplicate groups of fish (initial fish mean weight: $14.3{\pm}0.03g$) were fed the experimental diets to apparent satiation (twice daily at 08:00 and 18:00 h). After a 12-week feeding trial, a total of 180 healthy fish were randomly distributed into three Guelph system tanks at a density of 60 fish/tank (initial fish mean weight : $50.6{\pm}2.4g$) to test the apparent digestibility coefficients of the ingredients (ACSBM, fishmeal, and soybean meal). Although negative effects were observed with ACSBM40, ACSBM50 and ACSBM60 after 12 weeks of feeding, up to 20% of the fishmeal protein could be successfully replaced with ACSBM without significant growth depression. Hemoglobin and hematocrit values of fish fed the ACSBM50 and ACSBM60 diets were significantly lower than those of fish fed the ACSBM0 diet. Glucose values of fish fed the ACSBM60 diet were significantly higher than those of fish fed the ACSBM0 and ACSBM20 diets. Digestibility of protein in ACSBM and soybean meal was 85.9% and 82.5%, respectively. Results indicated that at least 20% of fishmeal protein can be replaced by ACSBM in diets of juvenile olive flounder without supplementation of limiting amino acids.

• ALGAE
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• 제22권3호
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• pp.235-240
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• 2007

The red tide-causing flagellate Chattonella anticfua can cause mass fish kills by their clogging in fish gills. Thisstudy examined the nutrient requirements of C. antiqua isolated from Korea. C. anticfua displayed maximum growthat the day five, followed by a decrease in cell density. Nitrate and nitrite were the preferred nitrogen sources, alonewith adenosine diphosphate for phosphorus compounds. In medium that contained ammonium, a significantdecrease in cell density was observed. Half-saturation constants, Ks, calculated from the maximum growth ratewere 4.94 U|M for NC>3 and 0.79 flM for P04. The growth of C. antiqua was not within the function of the N:P ratio (RU= 0.29). With an N:P ratio as low as 10, the increase in cell density was apparent, with a higher division rate. At lev-els above 50 fiM of NaNOg or 8 ;uM of NaHUPCU, the growth rates were somewhat decreased. Phosphate was thelimiting factor for C. antiqua growth since the starvation of phosphate had brought about a rapid decrease in celldensity in semi-continuous culture. Studies about the temporal modification of the efficiency of nitrate or phosphateuptake may be necessary to explain the bloom dynamics of C. antiaua.

• 한국어병학회지
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• 제15권1호
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• pp.37-42
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• 2002

Effect of mercury (Hg) toxicity on survival, growth, feed efficiency and oxygen consumption were examined in the juvenile olive flounder. Paralichthys olivaceus. Fishes were exposed to sublethal concentrations of Hg ranging from 0 to 0.13mg/L for 6 weeks. Hg reduced survival rate in a concentration and exposure period-dependent way and suddenly reduction occurred at Hg concentrations greater than 0.05mg/L after 6 weeks. Growth rate and feed efficiency also significantly decreased at greater than 0.028 and 0.05 mg/L respectively. Oxygen consumption rate was significantly decreased to 25 and 32% than that of the control at the Hg concentration of 0.05 and 0.13 mg/L respectively. These results suggest that Hg toxicity inhibit physiological function including growth, feed efficiency and oxygen consumption in the juvenile olive flounder, resulting in survival failure at high concentration.

• Fisheries and Aquatic Sciences
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• 제15권1호
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• pp.43-47
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• 2012

Growth hormone (GH) transgenesis in fish has the potential to improve aquaculture efficiency and capacity. However, many fast-growing transgenic fish have experienced side effects caused by excess GH expression. To overcome this unwanted issue associated with several GH transgenic mud loach Misgurnus mizolepis lines carrying GH construct driven by a strong ${\beta}$-actin regulator ($pml{\beta}$-actGH), we performed an alternative version of GH autotransgenesis using a weaker but more stable regulator, the mud loach lectin promoter. GH transgenesis with a pmlectGH construct consisting of the mud loach GH gene driven by the 2.3-kb lectin promoter exhibited significant growth stimulation. However, the extent of the growth acceleration in pmlectGH transgenics (six times maximum when assessed 2 months post hatching) was much less than that in transgenic individuals carrying the $pml{\beta}$-actGH construct. Additionally, the extraordinary gigantism that was common in $pml{\beta}$-actGH-transgenic mud loaches was diminished in transgenic loaches harboring the pmlectGH construct. Transgenic founders (pmlectGH) successfully transmitted their transgene into the next generation with up to 41% frequency. Growth stimulation also persisted in the transgenic F1 strains, with a seven-fold increase in maximum body weight at 6 months of age.

• 한국수산과학회지
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• 제37권4호
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• pp.307-311
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• 2004

Age and growth of red tongue sole (Cynoglossus joyneri), were studied using samples from the coastal waters off Yeosu, Korea, from January to December, 2001. Sagittal otoliths had relatively clear annuli. Marginal index of otolith dropped sharhly in August suggesting that each annulus was formed once a year In August. Monthly changes in the gonadosomatic index indicated that spawning peaked between July and September. The oldest fish observed in this study was 4 years old for both of females and males. Relationships between the otolith radius (R) and total length (L) were: L=14.1R-0.098 for females, and L=11.9R+1.83 for males. Relationships between total length and body weight $(W)\;were:\;W=0.0021L^{3.24}\;for\;females,\;and\;W=0.0014L^{3.39}$ for males. Growth in length of the fish was expressed by the von Bertalanffy's growth equation as:$L_{t}=29.06\;(1-e^{-0.19(t+2.40)})\;for\;females\;and\;L_{t}=27.44 (1-e^{-0.17(t+2.84)})$ for males.

• Fisheries and Aquatic Sciences
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• 제17권1호
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• pp.1-11
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• 2014

The Kenyan aquaculture sector is broadly categorized into freshwater aquaculture and mariculture. Whereas freshwater aquaculture has recorded significant progress over the last decade, the mariculture sector has yet to be fully exploited. The Kenyan aquaculture industry has seen slow growth for decades until recently, when the government-funded Economic Stimulus Program increased fish farming nationwide. Thus far, the program has facilitated the alleviation of poverty, spurred regional development, and led to increased commercial thinking among Kenyan fish farmers. Indeed, national aquaculture production grew from 1,000 MT/y in 2000 (equivalent to 1% of national fish production) to 12,000 MT/y, representing 7% of the national harvest, in 2010. The production is projected to hit 20,000 MT/y, representing 10% of total production and valued at USD 22.5 million over the next 5 years. The dominant aquaculture systems in Kenya include earthen and lined ponds, dams, and tanks distributed across the country. The most commonly farmed fish species are Nile tilapia Oreochromis niloticus, which accounts for about 75% of production, followed by African catfish Clarias gariepinus, which contributes about 21% of aquaculture production. Other species include common carp Cyprinus carpio, rainbow trout Oncorhynchus mykiss, koi carp Cyprinus carpio carpio, and goldfish Carassius auratus. Recently, Kenyan researchers have begun culturing native fish species such as Labeo victorianus and Labeo cylindricus at the National Aquaculture Research Development and Training Centre in Sagana. Apart from limited knowledge of modern aquaculture technology, the Kenyan aquaculture sector still suffers from an inadequate supply of certified quality seed fish and feed, incomprehensive aquaculture policy, and low funding for research. Glaring opportunities in the Kenyan aquaculture industry include the production of live fish food, e.g., Artemia, daphnia and rotifers, marine fish and shellfish larviculture; seaweed farming; cage culture; integrated fish farming; culture of indigenous fish species; and investment in the fish feed industry.

• 한국발생생물학회지:발생과생식
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• 제13권4호
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• pp.239-247
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• 2009

속성장 육종 넙치(selected line of olive flounder cultured, SF)의 수정란의 부화율 및 기형률, 자치어의 성장을 일반 넙치(unselected line of olive flounder cultured, UF)와 비교하였다. 동일한 날에 획득한 SF구 및 UF구 수정란의 부화율은 SF구가 96.2${\pm}$1.7%, UF구는 90.4${\pm}$2.1%로 SF구가 높았으며, 기형률은 UF가 유의하게 높았다. 이들 수정란으로부터 부화한 자어를 8주 동안 사육한 결과, 부화후 1주째에 SF 및 UF구의 전장은 각각 4.36${\pm}$0.24, 4.25${\pm}$0.20 mm였던 것이 실험 종료시에 각각 50.49${\pm}$2.67, 40.55${\pm}$3.13 mm로 SF구가 UF구에 비해 24.5% 빨랐다. 체고는 부화후 1주째에 각각 1.13${\pm}$0.08, 1.18${\pm}$0.07 mm였으며, 종료시에 각각 16.30${\pm}$0.085, 13.50${\pm}$0.96 mm로 SF가 UF구에 비해 20.7% 크게 나타났다. 실험 종료시에 체중은 각각 1.036${\pm}$0.118, 0.557${\pm}$0.073 g으로 SF구가 UF에 비해 43.0% 빨랐다. 또한 실험 종료시에 SF구와 UF구의 체형지수는 각각 0.85${\pm}$0.02, 0.82${\pm}$0.03으로 SF구가 유의하게 높았으며, 비만도는 각각 7.99${\pm}$0.33, 8.22${\pm}$0.52로 SF구가 UF구에 비해 낮았다. 이상의 결과는 속성장을 위해 선발 육종된 넙치가 일반 넙치에 비해 성장이 월등이 우수하며, 체형이 자연산 넙치에 가깝게 개선되었음을 나타내었다.

• 한국양식학회지
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• 제4권1호
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• pp.1-12
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• 1991

1987년 4월 10일부터 10월 16일까지 $4,000\;\ell$ 콘크리트 탱크 및 $270\;\ell$ 유리 수조를 이용한 폐쇄순환여과사육장치내에서 크기에 따른 일일성장률과 사료계수를 측정하기 위하여 다음과 같은 실험을 실시하였다. 실험에 사용된 어체의 크기는 평균체중 7 g 에서 1,000 g 되는 일본계통 틸라피아 Oreoohromis niloticus 였다. 매실험마다 최초방양 무게는 콘크리트 탱크에서는 200 kg (수량의 $5{\%}$), 유리 수조에서는 $10{\~}20$ kg (수량의 $3.7\%{\~}7.4\%$)으로 조절하였다. 매실험사육기간은 14일 전후였다. 수온은 $26^{\circ}C$ 내외로 유지시키도록 했는데, 약간의 변화는 피할 수 없었다. 용존산소는 약 $3\;mg/\ell$ 이내로 조절하였으며, 암모니아는 유리 수조에서 일시 $18\;mg/\ell$ 까지 상승한 적도 있으나, 일반적으로 $4\;mg/\ell$ 이었으며, 콘크리트 탱크에서는 약 $1\;mg/\ell$ 로 유지되었다. 어체중 약 10 g에서의 사료계수는 0.9, 일일성장률은 $3.5{\%}$ 였으며, 어체중 약 800 g 때의 콘크리트 탱크에서의 일일성장률은 $0.8{\%}$, 유리 수조에서의 일일성장률은 약 $0.5{\%}$이었다. 실험어는 대두정을 주성분으로 한 $32{\%}$ 조단백질을 함유한 사료를 공급하였다. 이번 실험의 결과에 따라서 식용어로 될 수 있는 틸라피아를 생산하는데 소요되는 기간은 계산상 다음과 같이 나타났다 즉, 콘크리트 탱크($7m^{2}$)에서는 50 g 되는 치어를 방양하여 1,000 g 까지 기르는데 223일 걸리며, 유리 수조에서는 10 g되는 치어를 방양 800 g 까지 기르는데 302일이 걸린다.