• 한국수산과학회지
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• 제49권2호
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• pp.168-175
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• 2016

We conducted a 90-day feeding experiment to evaluate the growth and energy budget of the sea cucumber Apostichopus japonicus. Sea cucumbers with a mean initial wet body weight of 3.03±0.06 g were fed one of the following three diets: an eel fecal solid diet, rainbow trout fecal solid diet, or a commercial diet at a water temperature of 17±1℃ and salinity of 32±1 psu. The results suggested that the diets affected the final body weight, specific growth rate (SGR), food ingestion, feces production ratio, and hence the growth and energy budget of the sea cucumbers. Sea cucumbers fed the eel and rainbow trout fecal solid diets showed poorer energy absorption, assimilation, and growth than those fed the commercial diet. The sea cucumbers fed the commercial diet had a significantly higher SGR and proportion of energy used for growth than those fed the other two diets. Sea cucumbers fed the rainbow trout fecal solid diet showed a comparatively higher ingestion rate and feces production ratio than those fed the commercial diet. The eel and rainbow trout fecal solid diets, therefore, were not suitable for sea cucumbers in intensive cultivation. Our findings will facilitate further development of more appropriate diets for culture of sea cucumber.

• 한국수산과학회지
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• 제49권3호
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• pp.270-276
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• 2016

This study investigated the sensory characteristics (texture, odor, taste and color) of jerky produced from ground sea rainbow trout (SRT) Oncorhynchus mykiss frame muscle (FM). The hardness of the ground SRT-FM jerky was 453.9±91.0 g/cm², which was lower than that of commercial animal jerky (893.5±404.6 g/cm²) and commercial fish jerky (1,394.4±363.5 g/cm²). The difference in the hardness values of the ground SRT-FM jerky and commercial animal jerky was not significant. The volatile basic nitrogen content of the ground SRT-FM jerky was 48.3±1.6 mg/100 g, which was higher than that of commercial fish jerky (21.6±6.2 mg/100 g) and commercial animal jerky (18.2±6.3 mg/100 g). However, the fish odor of the ground SRT-FM jerky was masked by the presence of various additives. The hydrophilic and lipophilic browning indices of the ground SRT-FM jerky were higher than those of the commercial jerky. The total taste value of the ground SRT-FM jerky was 169.0, and the major amino acids were glutamic acid and aspartic acid. These results suggest that ground SRT-FM jerky would be acceptable to consumers.

• 한국수산과학회지
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• 제49권3호
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• pp.263-269
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• 2016

Large quantities of by-products—such as fish frame, head, skin and viscera—are generated during seafood processing, and these by-products are not utilized extensively. Therefore, sea rainbow trout Oncorhynchus mykiss (SRT) frame muscle (FM) jerky was prepared by grinding SRT-FM, followed by mixing with seasoning, forming and drying. The nutritional and microbiological characteristics of the SRT-FM jerky were then investigated. The proximate composition of the SRT-FM jerky was 19.1% moisture, 38.7% crude protein, 7.9% crude lipid and 4.4% ash. The viable bacterium count of the SRT-FM jerky was 3.9 log CFU/g, and Escherichia coli and Staphylococcus aureus were not detected. The total amino acid content of SRT-FM jerky was 37.3 g/100 g, and the major amino acids were aspartic acid, glutamic acid, leucine and lysine. Based on the recommended daily intake of fish jerky (100 g), the most abundant mineral was potassium. The fatty acid composition of the SRT-FM jerky was 26.2% saturated acid, 34.5% monoenoic acid and 39.3% polyenoic acid, and the major fatty acids were 16:0, 18:1n-9, 18:2n-6, 20:5n-3 and 22:6n-3. These results suggest that SRT-FM jerky has high nutritional value.

• 한국수산과학회지
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• 제44권3호
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• pp.225-231
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• 2011

Prolactin (PRL) plays an important role in freshwater (FW) osmoregulation by preventing the loss of ions and the uptake of water in fish. Growth hormone (GH) promotes acclimation to seawater (SW) in several teleosts. We acclimated rainbow trout Oncorhynchus mykiss weighting $68.2{\pm}16.6$, $138.3{\pm}24$, and $287.5{\pm}42.1$ g in separate experiments to SW under slow-acclimation (SSW) or acute-acclimation (ASW) conditions, and then examined the PRL and GH mRNA levels using the real-time quantitative polymerase chain reaction. The PRL mRNA levels in all three experimental groups decreased significantly with both the SSW and ASW treatments, as compared to a control group kept in FW for 30 days. The GH mRNA levels increased with ASW in the largest fish, whereas the levels in the other groups did not change significantly. The mortality rate of the largest fish was lower than for the other groups, whereas the growth rate among the three experimental groups did not differ significantly. The growth rate of the ASW group was highest for the smallest fish. These results suggest that SW acclimation is associated with the gene expression levels of PRL and GH in relatively large rainbow trout. In addition, the fish mortality and growth rate on FW-SW transfer seem to be related to body weight, and the SW acclimation method may be applied to the hatcheries industry.

• 한국수산과학회지
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• 제51권3호
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• pp.254-261
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• 2018

From 2014 to 2017, mortalities of seawater-cultured rainbow trout Oncorhynchus mykiss, were observed in the Goheung and Jeju areas of Korea, with Vibrio anguillarum (seven strains: RT1, 2, 3, 4, 5, 6, and 7) identified as the etiological agent. The phenotypic (based on API 20NE, API ZYM, and E-test kits), serotypic (slide agglutination tests with O1, O2, O3, O4, and O7 antisera), and genotypic (16S rRNA and ompU sequencing) characteristics of the seven RT strains were analyzed and compared to those of seven additional V. anguillarum stains (SF, isolated from sweet fish; FM, isolated from flathead mullet; ATCC43305; ATCC43311; ATCC43307; ATCC43308; and KCTC2711). The phenotypes of the RT strains showed variance, while the slide agglutination tests of the RT1-7, SF, and FM strains all showed positive reactions with serotype O1 antiserum. The 16S rRNA and ompU sequences of the RT1-7, SF, and FM strains were affiliated with V. anguillarum ATCC43305 (Serotype O1), but the ompU sequence of the SF strain differed from those of the RT1-7, FM, and ATCC43311 strains, including one amino acid substitution. We thus confirmed that serotype O1 V. anguillarum, with multiple phenotypes, continues to infect seawater-cultured rainbow trout in Korea.

• Asian-Australasian Journal of Animal Sciences
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• 제28권4호
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• pp.551-558
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• 2015

This study was carried out to evaluate the dietary threonine requirement by measuring the plasma free threonine and ammonia concentrations in rainbow trout, Oncorhynchus mykiss after dorsal aorta cannulation. A total of 70 fish (average initial weight $506{\pm}8.2g$) were randomly distributed into each of the 14 net cages (5 fish/cage). After 48 hours (h) of feed deprivation, each group was intubated at 1% body weight with one of the seven L-amino acid based diets containing graded levels of threonine (0.42%, 0.72%, 0.92%, 1.12%, 1.32%, 1.52%, or 1.82% of diet, dry matter basis). Blood samples were taken at 0, 5, and 24 h after intubation. Post-prandial plasma free threonine concentrations (PPthr) of fish 5 h after intubation with diets containing 1.32% or more threonine were significantly higher than those of fish intubated with diets containing 1.12% or less threonine (p<0.05). Post-absorptive free threonine concentrations (PAthr) after 24 h of intubation of the fish with diets containing 0.92% or more threonine were significantly higher than those of fish intubated with diets containing 0.72% or less threonine. Post-prandial plasma ammonia concentrations (PPA, 5 h after intubation) were not significantly different among fish intubated with diets containing 1.12% or less threonine, except the PPA of fish intubated with diet containing 0.42% threonine. Broken-line model analyses of PPthr, PAthr, and PPA indicated that the dietary threonine requirement of rainbow trout should be between 0.95% (2.71) and 1.07% (3.06) of diet (% of dietary protein on a dry matter basis).

• 한국수산과학회지
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• 제48권1호
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• pp.26-35
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• 2015

This study compared the meat quality of sea rainbow trout Oncorhynchus mykiss frame muscle (S-FR-TY) and fillet (S-FI-TY) with the frame muscle of freshwater rainbow trout (F-FR). There was a difference of < 1% in the proximate composition of S-FR-TY vs. S-FI-TY, and of S-FR-TY vs. F-FR. The Hunter a value of F-FR-TY was lower compared with that of F-FR cultured in Jecheon (F-FR-JC), but higher than that of F-FR cultured in Pyeongtaek (F-FR-PT). However, no difference in the Hunter a value of S-FR-TY compared with any other F-FR was observed. The odor intensity of S-FR-TY was lower compared with that of F-FR, while the taste of S-FR-TY was milder than that of S-FI-TY, but stronger than that of F-FR. Although its total amino acid content was lower, the essential amino acid content of S-FR-TY was higher compared with S-FI-TY; the potassium content of S-FR-TY was also significantly greater. S-FR-TY contained high levels of nutritional and functional components, such as anserine, lysine, threonine, and eicosapentaenoic and docosahexaenoic acid. These results suggest that S-FR-TY could be used as a resource of canned food or fish jerky for children.

• 한국어병학회지
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• 제27권2호
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• pp.133-137
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• 2014

본 연구에서는 2013년 4월 제주 소재 육상수조에서 무지개송어 해수순치 과정중에 대량폐사가 발생하여 질병검사를 실시하였다. 병어의 대부분은 체표에 궤양이 형성되어 있었고, 비장 비대, 유문수 부위 및 복강 근육의 출혈 및 위속에 액성물질이 가득 차 있었다. 병원체 검사결과, 기생충, 진균, 바이러스는 검출되지 않았지만 검사 개체 5마리에서 간, 비장 및 신장조직에서 동일한 형태의 세균 colony가 시료 당 200개 이상 분리되었다. 분리세균의 16S rDNA 염기서열 분석 결과, Vibrio anguillarum과 100% (875/875 bp) 일치하였다. 이상의 결과, 무지개송어 해수 순치과정 중에 발생된 질병은 Vibrio anguillarum 감염증으로 사료되었다.

• 한국수산과학회지
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• 제47권6호
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• pp.832-839
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• 2014

To evaluate the digestive characteristics and bioavailability of dietary soybean meal (SBM), the post-prandial changes in the gastric contents of rainbow trout Oncorhynchus mykiss were determined for 24 h after feeding of SBM diets. A curve estimation of regression diagnostics using a comparison of the adjusted $r^2$ and probability was performed to test the tendency of the post-prandial changes and gave a quadratic polynomial (exponential) regression for all experimental groups. The gastric evacuations rates (GER) for higher-SBM groups were slower than those for lower-SBM groups. The estimated GER (digestion time) for 75% gastric content for fish fed a 70% SBM diet was 1.63 times longer than that for fish fed the control diet. Despite the fact that the pH values in the gastric contents rose from 4.05 at 0 h to 5.12-5.38 at 1 h after feeding, then dropped to 4.57-4.83 at 9 h, with no significant differences among experimental groups, the gastric moisture contents increased significantly in the higher-SBM groups. This is most likely due to an increase in digestive juices in the higher-SBM groups, rather than water introduced externally. The percentage of soluble nitrogen in the gastric contents of fish fed the higher-SBM diets was higher than that in the fish fed the control diet, and the SBRs (stomach weight/body weight${\times}100$) in the higher-SBM groups (diets 4, 5, 6 and 7) were also significantly higher than the SBR of the control group (P<0.05). This may indicate that the protein in SBM can be digested slowly due to physiological digestive adaptation in rainbow trout.

• 한국양식학회지
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• 제13권1호
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• pp.79-85
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• 2000

자성 및 웅성스테로이드 호르몬들이 Vg 유전자발현에 영향을 미치는지를 미성숙 무지개송어의 배양간세포 막간을 이용하여 조사하였다. 이미 보고된 송어의 Vg gene의 염기배열을 참고로 Vg cDNA 단편(600 bp)을 증폭시킬 수 있는 primer들을 작성하였다. 이들 primer를 이용하여 증폭된 PCR 산물의 염기배열을 결정하여 송어의 Vg cDNA임을 확인하였고, RT-PCR법을 이용하여 배양간세포 그리고 E$_2$ 및 MT 처리된 송어의 간으로부터 Vg mRNA의 전사량 변화를 조사하였다. 호르몬 처리된 간세포 및 송어의 간에서 추출한 total RNA를 이용하여 RT-PCR법으로 분석한 결과 in vivo, in vitro 실험 모두에서 E$_2$ 또는 MT처리된 간세포 및 송어의 간으로부터 Vg mRNA와 Vg 단백질합성이 유도되었고, 이들의 증가 경향은 처리된 호르몬 농도 및 시간에 의존하고 있음이 밝혀졌다. 또한 progesterone, androsterone 그리고 testosterone 등의 웅성호르몬들도 Vg mRNA의 전사를 유도하고 있다는 것이 시사되었다. 이와 같은 결과로부터E$_2$ 뿐 아니라 웅성스테로이드들도 Vg mRNA의 발현을 유도하고 있음이 송어의 in vivo 또는 in vitro 실험에 의해서 확인되었다.