• 한국수산과학회지
• /
• 제49권1호
• /
• pp.38-44
• /
• 2016

The quality and quantity of live food sources strongly influence the success of fish production in farming operations. Thus, critical studies of live forage species are a crucial element for progress in fish aquaculture. The fat content of food is an especially important determinant of growth in marine fish. Omega-3 highly unsaturated fatty acids (HUFA) are essential components of diet that determine the nutritional value of larval fish. Euglena is a protist that has potential as a forage species. These single-celled organisms have plant and animal characteristics they are motile, elliptical in shape and 15–500 μm in diameter. Their nutritional content is excellent, but most studies have focused on cells raised in autotrophic culture. We therefore examined differences in the lipid and fatty acid contents, and the growth of Euglena cells grown under autotrophic, heterotrophic, and mixotrophic conditions. Biomass production reached 15.03 g/L, 12.28 g/L, and 3.66 g/L under mixotrophy, heterotrophy, and autotrophy, respectively. The proportional n-3 HUFA content differed among culture methods: 10.04%, 5.80% and 10.01% in mixotrophic, heterotrophic and autotrophic cultures, respectively. Mixotrophy was to be the best form of cultivation for improving the growth and nutritional content of Euglena.

• 한국패류학회지
• /
• 제28권4호
• /
• pp.293-303
• /
• 2012

I. galbana, P. lutheri 및 C. simplex 3종을 먹이로 공급하며, 미세조류 종류에 따른 피조개 유생과 부착치패의 성장과 생존율 등을 비교하였다. 서로 다른 미세조류 3종을 단일 또는 혼합하여 먹이로 공급한 피조개 유생의 성장은 혼합 공급구에서 가장 빠르게 나타내었고, 단일 공급구 중에서 C. simplex 공급구에서 가장 높은 성장을 보였다. 또 유생의 생존율은 혼합 공급구에서 $27.4{\pm}5.3%$로 가장 높게 나타내었고, 단일 공급구 중에서 C. simplex 공급구에서 $14.5{\pm}2.3%$로 가장 높았다. I. galbana, P. lutheri, C. simplex 3종을 단일 또는 동일비율로 혼합한 미세조류의 지방산 조성은 EPA의 경우 C. simplex에서만 $25.9{\pm}0.64%$로 나타났고, 다불포화지방산(PUFA)과 n-3 HUFA 함량은 C. simplex에서 가장 높게 나타났다. 또 이들 미세조류를 먹이로 공급한 피조개 부착치패의 경우 C. simplex 공급구에서 포화지방산과 AA 함량이 유의하게 높았다. 이와 같은 C. simplex의 지방산 조성이 피조개 유생과 부착치패의 성장과 생존율의 원인으로 판단된다. 따라서 단일종으로는 C. simplex가 가장 적합하나 3종을 혼합하여 공급하는 것이 더 좋은 먹이효율을 유도할 수 있다.

• 한국어업기술학회:학술대회논문집
• /
• 한국어업기술학회 2000년도 춘계수산관련학회 공동학술대회발표요지집
• /
• pp.288-289
• /
• 2000

양식산업에서 널리 이용되는 rotifer와 같은 먹이생물의 고도 불포화지방산 (n-3 HUFA)함량은 양식 초기의 치자어의 정상적인 생존 및 성장을 위해서 필수적이다. 그러나 담수산 농축 Chlorella를 이용하여 대량 배양한 rotifer들은 고도 불포화 지방산 함량이 낮아 해산 어류 자어에 먹이로 공급시 문제점으로 보고되고 있다 (Yoshimatu et al., 1997). 따라서 영양강화를 위한 여러 가지 2차 배양법이 실시되고 있다. 이들 2차 배양은 고도 불포화 지방산 함량이 높은 emulsified oil이 주로 사용되고 있으나, Park et al.(1999)에 의하면 emulsified oil은 rotifer들의 흡착을 유발하여 개체수 감소 등의 문제점을 유발한다고 보고하였다. (중략)

• 한국양식학회지
• /
• 제20권2호
• /
• pp.90-95
• /
• 2007

전라남도 여수시 가막만에 방류한 감성돔, Acanthopagrus schlegli 치어의 초기 먹이섭취 및 먹이조성 그리고 체성분 변화에 대해 1개월간 추적연구를 수행하였다. 방류 감성돔은 방류 후 1일째부터 먹이섭취가 이루어졌으며, 포식율은 조사기간 동안 80% 이상을 보였다. 먹이조성은 방류 후 15일째까지 낚시미끼와 가두리에서의 사료 유출물 등 인공먹이를 주로 섭취하였으나, 그 후 20일 이후부터 자연먹이로의 전환이 이루어졌다. 방류 후 5일 그리고 10일째의 A 정점(SA) 방류 감성돔의 전어체 조지방 함량이 방류전, B 정점(SB) 그리고 양식어(CUL)보다 낮은 값을 보였으며, 방류 30일째의 전어체의 n-3 HUFA 조성 및 필수아미노산 함량은 방류어에서 약간 높은 경향을 보였다. 본 연구 결과, 가막만에 방류된 감성돔은 빠른 먹이섭취가 이루어졌으며, 초기 먹이섭취 및 먹이조성은 어체성분 변화에 영향을 미치는 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제22권4호
• /
• pp.565-575
• /
• 2009

Two experiments in the sequential order were conducted to determine the effects of different dietary lipid sources on the growth and fatty acid composition of rohu (Labeo rohita) and to examine the viability of a return fish oil finisher diet in restoring the human cardio-protective fatty acid profile. In the first experiment, fish were fed either with coconut oil (D1), olive oil (D2), sunflower oil (D3), linseed oil (D4) and fish oil (D5) as the main lipid source in the isonitrogenous diet for 90 days. No significant differences in growth were observed. Among the experimental diets moisture content of fish varied significantly (p<0.05) between the groups. Dietary lipid sources had a profound influence on the fatty acid profile of the muscle and liver as tissue fatty acid profile reflected the dietary fatty acid composition. Increased amounts of eicosapentaenoic acid and docosahexaenoic acid were observed in tissue of fish fed D4 and arachidonic acid was observed in the tissue of fish fed D3. We have also detected the metabolites of n-3 and n-6 pathway in D4 and D3 groups respectively, which prompted us to conclude that rohu, can desaturate and elongate $C_{18}$ essential fatty acids to $C_{20}$ and $C_{22}$ HUFA. A second feeding trial was conducted using the animals from the five different treatment groups for the duration of 30 days with fish oil rich diet (D5). Feeding with fish-oil rich washout diet resulted in the near equalization of all the other treatment groups tissue fatty acid profiles to that of fish oil (D5) fed group. These results indicate that a finishing fish oil diet can be effectively used to restore the human cardioprotective fatty acid profile in rohu fed with vegetable oils as lipid source.

• Asian-Australasian Journal of Animal Sciences
• /
• 제25권6호
• /
• pp.869-879
• /
• 2012

This study was conducted to investigate the effects of dietary lipid source and level on growth performance, blood parameters, fatty acid composition and flesh quality of sub-adult olive flounder Paralichthys olivaceus. Eight experimental diets were formulated to contain 5% squid liver oil (SLO), 5% linseed oil (LO), 5% soybean oil (SO), a mixture of 1% squid liver oil, 2% linseed oil and 2% soybean oil (MIX), no lipid supplementation with high protein level (LL-HP), 10% squid liver oil (HL-SLO), a mixture of 1% squid liver oil, 4.5% linseed oil and 4.5% soybean oil (HL-VO), and 1% squid liver oil with high starch level (LL-HC), respectively. Two replicate groups of fish (average initial weight of 296 g) were fed the diets for 17 wks. After 5 wks, 11 wks and the end of the feeding trial, five fish from each tank were randomly sampled for analysis of body composition. At the end of the feeding trial, final mean weight of fish fed the LL-HP diet was significantly (p<0.05) higher than that of fish fed the HL-VO diet, but did not differ significantly from those of fish fed the SLO, LO, SO, MIX, HL-SLO and LL-HC diets. Fish fed the LL-HP diet showed significantly higher feed efficiency than fish fed the LO, HL-SLO and HL-VO diets. Feed efficiency of fish fed the LO, SO and MIX diets were similar to those of fish fed the SLO and HL-SLO diets. Fish fed the HL-SLO diet showed significantly higher total cholesterol content in plasma compared with other diets. Fatty acid composition of tissues was reflected by dietary fatty acid composition. The highest linoleic (LA) and linolenic acid (LNA) contents in the dorsal muscle were observed in fish fed the SO and LO diets, respectively, regardless of feeding period. The highest eicosapentaenoic acid (EPA) content in the dorsal muscle was observed in fish fed the LL-HP and LL-HC diets after 11 and 17 weeks of feeding, respectively. Fish fed the SLO and HL-SLO diets showed higher docosahexaenoic acid (DHA) content than that of other treatments after 11 and 17 weeks of feeding, respectively. Dietary inclusion of vegetable oils reduced n-3 HUFA contents in the dorsal muscle and liver of fish. The n-3 HUFA contents in tissues of fish fed the SLO and HL-SLO diets were higher than those of fish fed other diets, except for the LL-HP and LL-HC diets. Hardness, gel strength, chewiness and cohesiveness values of dorsal muscle in fish were significantly affected by dietary lipid source. The results of this study indicate that fish oil in fish meal based diets for sub-adult olive flounder could be replaced by soybean oil and linseed oil without negative effects on growth and feed utilization.

• 한국수산과학회지
• /
• 제45권4호
• /
• pp.343-350
• /
• 2012

Even though the microalgal species of Isochrysis and Pavlova are widely used as live food in bivalve hatcheries, they are difficult to culture in mass during the summer season. Therefore, the present study was conducted to determine the optimum species or strains of Isochrysis and Pavlova to produce good growth and high contents of fatty acids at temperatures over $30^{\circ}C$. Four species of Isochrysis (I. galbana KMMCC12, I. galbana KMMCC214, I. aff. galbana, and Isochrysis sp.) and four of Pavlova (P. lutheri, P. gyrans, P. viridis, and Pavlova sp.) were cultured at $25^{\circ}C$, $29^{\circ}C$, and $33^{\circ}C$, and then analyzed for specific growth rate and fatty acid composition. Microalgae were cultured in f/2 medium at 23 psu and continuous light of $80{\mu}mol$ photons $m^{-2}s^{-1}$. For the I. galbana, growth rates were highest at $29^{\circ}C$ and decreased at $33^{\circ}C$ to the level observed at $25^{\circ}C$. I. galbana (KMMCC12) and Isochrysis sp. cultured at $29^{\circ}C$ and $33^{\circ}C$, respectively, exhibited the highest growth rates of all Isochrysis species. In terms of fatty acids, I. galbana (KMMCC12) contained higher contents of PUFA and n-3 HUFA at $33^{\circ}C$ than did Isochrysis sp. For species of Pavlova, growth rates of P. gyrans and P. viridis at $29^{\circ}C$ and $33^{\circ}C$, respectively, were higher than those of the other Pavlova species. In particular, P. viridis grew as well at $33^{\circ}C$ as it did at $29^{\circ}C$. However, P. lutheri and Pavlova sp. did not grow at $33^{\circ}C$. In terms of fatty acids, P. viridis cultured at $33^{\circ}C$ also exhibited higher contents of PUFA and n-3 HUFA, as compared to P. gyrans. Based on these results, we suggest that I. galbana (KMMCC12) and P. viridis are suitable species for mass culture during the high temperature season.

• ALGAE
• /
• 제28권1호
• /
• pp.101-109
• /
• 2013

Some Chlorella species grow heterotrophically with organic substrate in dark condition. However, heterotrophic Chlorella species are limited and their optimum culture conditions are not fully known. In this study, three heterotrophic Chlorella species, two strains (C4-3 and C4-4) of C. vulgaris and one Chlorella sp. (C4-8) were examined on optimum culture conditions such as carbon source, temperature, and concentrations of nitrogen and phosphorus in Jaworski's medium (JM). And the growth and fatty acid composition of Chlorella were analyzed. For three heterotrophic Chlorella species, glucose (1-2%) as a carbon source only increased the growth and the range of optimum culture temperature was $26-28^{\circ}C$. Doubled concentrations of the nitrogen or phosphorus in JM medium also improved the growth of Chlorella. Chlorella cultured heterotrophically showed significantly higher growth rate and bigger cell size than those autotrophically did. C. vulgaris (C4-3) cultured heterotrophically showed the highest biomass in dry weight ($0.8g\;L^{-1}$) among three species. With respect to fatty acid composition, the contents of C16:0 and n-3 highly unsaturated fatty acid (HUFA) were significantly higher in autotrophic Chlorella than in heterotrophic one and those of total lipid were not different between different concentrations of nitrogen and phosphorus in JM medium. Among three Chlorella species in this study, C. vulgaris (C4-3) appeared to be the most ideal heterotrophic Chlorella species for industrial application since it had a high biomass and lipid content.

• 한국패류학회지
• /
• 제26권3호
• /
• pp.217-225
• /
• 2010

성장기 해역별 해만가리비의 총지질 함량은 8월 통영해역에서 가장 높았으나, 9월과 10월에는 감소하였고 11월에는 가장 낮은 수치로 현저히 감소하였다. 해역별 phytoplankton의 총 지질함량은 통영해역에서 가장 높은 것으로 나타나 통영해역에서의 가장 성장이 좋은 결과와 잘 일치하여 먹이생물인 phytoplankton의 총지질 함량이 해만가리비의 성장에 중요한 역할을 하는 것으로 보인다. 통영해역은 8월에 최고를, 11월에는 감소하는 경향을 나타냈다. 성장기에 있어서 해만가리비의 해역별 계절에 따른 지방산 조성중 포화지방산으로서는 16:0, 18:0가 주성분을 이루었고, 불포화지방산인 monoenoic acid는 16:1n-7, 18:1n-7, 20:1n-9, ARA (20:4n-6), EPA (20:5n-3), DHA (22:6n-3) 가 주성분이었다. 해만가리비의 성장기 (8-11월) 에 있어서 해역별 phytoplankton의 지방산 조성은 여름철인 8월에 오메가-3 고도불포화지방산은 성장이 나쁜 남해 해역이 높은데 비하여 통영과 남면해역은 낮았다.

• 한국수산과학회지
• /
• 제44권4호
• /
• pp.339-344
• /
• 2011

We investigated the effects of enrichment with oil or bacteria on the fatty acid composition of rotifers and Artemia as live prey. One enrichment(oil source) was mainly composed of squid Todarodes pacificus liver oil; the other(photosynthetic-bacterial source) was primarily made up of Schizochytrium sp. The enrichments were intended to enhance the nutritional value of the live prey, such as their EPA, DHA and n-3 HUFA contents. The lipid content as EPA and DHA of rotifers was higher when enriched with the oil source rather than the photosynthetic-bacterial source. The DHA content of Artemia nauplii after enrichment differed significantly, depending on the type of enrichment used(P<0.05). When the Artemia nauplii were enriched with the oil source, the DHA content was increased to 16.8%, whereas it increased only to 1.1% when enriched with the photosynthetic-bacterial source. These results indicate that selection of the enrichment is important for Artemia nauplii but not for rotifers.