• Fisheries and Aquatic Sciences
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• v.20 no.10
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• pp.24.1-24.8
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• 2017

The experiment was conducted to investigate the effects of different algae in diet on growth, survival, and interleukin-10 productions of sea cucumber. At first, a 9-week feeding trail was conducted to evaluate the growth performance and survival of the sea cucumber fed one of the six experimental diets containing ST (Sargassum thunbergii), UL (Ulva lactuca), UP (Undaria pinnatifida), LJ (Laminaria japonica), SS (Schizochytrium sp.), and NO (Nannochloropsis oculata) in a recirculating aquaculture system. The result showed that survival was not significantly different among the dietary treatments, and the specific growth rate (SGR) of sea cucumber fed the UL diet ($1.58%d^{-1}$) was significantly higher than that of sea cucumber fed the other diets (P < 0.05), except for the LJ and NO diets. Secondly, interleukin (IL)-10 gene expression was determined where mice splenocytes were stimulated with $10{\mu}g\;ml^{-1}$ of sea cucumber extracts for 2 h. The result showed that IL-10 gene expression levels were significantly increased in UL, LJ, and NO diets fed sea cucumber extracts compared to other experimental diets. The results suggest that dietary inclusion with Ulva lactuca, Laminaria japonica, and Nannochloropsis oculata algae may improve the growth of juvenile sea cucumber and could upregulate IL-10 gene expression in mice splenocytes. Such detailed information could be helpful in further development of more appropriate diets for sea cucumber culture.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.586-590
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• 2003

The effect of water temperature and feed on the growth, survival, and body composition of juvenile abalone (Haliotis discus hannai) fed an artificial formulated diet and a macroalgae (Laminaria japonica) for 12 weeks was investigated. Rearing temperature was maintained at $13{\circ}C,\;16{\circ}C,\;19{\circ}C$ by heated and natural sea water temperatures $(7.5-10.2{\circ}C).$ Shell growth, weight gain, and survival rate of the abalone were affected by water temperature and diet (P<0.05). Survival and growth rate of the abalone fed with the formulated diet and Laminaria at $19{\circ}C$ was significantly higher than those of the abalone fed the formulated diet or Laminaria at $13{\circ}C,\;16{\circ}C,$ and ambient temperatures (P<0.05). Moisture, crude protein, crude lipid, and ash contents of the soft whole body were affected mainly by diet than rearing water temperature (P<0.05). These indicate that a mixture of formulated diet and macroalgae could improve the growth of the abalone independent of water temperature and heated water could improve the growth of abalone during the winter season.

• Fisheries and Aquatic Sciences
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• v.26 no.8
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• pp.461-469
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• 2023

The objective of this study was to evaluate how the tank colours may change the effects of extreme temperature on the survival, growth, and quality of juvenile golden trevally (Gnathanodon speciosus). The experiment was set up with fifteen treatments of five tank colours (blue, red, yellow, grey, and white) and three temperatures (30℃, 32℃, 34℃) with three replications. Fish performance was assessed for four weeks. The results showed that tank colours and elevated temperatures affected the quality of golden trevally juveniles. The survival and growth rate of fish tend to decrease gradually, but the deformation rate of fish tended to increase in the order of tank colours: red, yellow > grey, blue, and white. The growth and survival rate of fish gradually decreased when the rearing temperature increased from 30℃ to 34℃ and this effect was independent of tank colors. Importantly, the deformation rate increased under elevated temperature, particularly in blue and white tanks with potential long-term effects. It is, therefore, not recommended to use blue and white tanks for rearing the golden trevally juveniles, particularly during extremely high temperatures from heatwave events.

• Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.339-345
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• 2011

Although culture techniques for the abalone Haliotis discus hannai are well known, mass culture of the benthic microalgae that are essential live food for the abalone larvae is still not practiced. This study was conducted to identify the microalgal species suitable for the growth of early larvae of H. discus hannai. The growth and attachment rates of 31 microalgal species were examined. Acrylic plates were used as the substrate. Among the 31 microalgal species, nine showing high growth and attachment rates were selected and tested for their dietary values via factors including settlement, metamorphosis, and survival rates of abalone larvae. Tetraselmis hazeni and Rhaphoneis sp. induced the highest settlement rate (65-69%) in abalone larvae. The metamorphosis rate was highest (57%) in larvae fed Rhaphoneis sp. and was also significantly higher in larvae fed Oscillatoria splendida (29%) and T. hazeni (22%) than in those fed other species. The highest survival rate of the larvae during the 15 days after metamorphosis was 67% in those fed Rhaphoneis sp., followed by T. hazeni (42%) and O. splendida (35%). In conclusion, Rhaphoneis sp. is the most suitable diatom for use as a live food for the culture of early larvae of H. discus hannai. In addition, T. hazeni and O. splendida are also potential species to be further developed and utilized in larval culture.

• Journal of Marine Life Science
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• v.7 no.2
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• pp.86-93
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• 2022

The ecotoxicity test method using Undaria pinnatifida spore is challenging to use throughout the year. Since U. pinnatifida female gametophytes can be cultured in the laboratory, they can be used for ecotoxicity testing at any time. Changes in female gametophyte survival rate and relative growth rate in U. pinnatifida exposed to various environmental conditions were analyzed. The female gametophyte of U. pinnatifida was exposed to salinity (5~40 psu), temperature (5~30℃), pH (4~10), and light intensity (0~120 μmol photon m^-2 s^-1). Based on the highest average value, the survival rate of female gametophyte was highest at a temperature of 20℃, salinity 27.5 psu, pH 8, and light intensity 30 μmol photon m^-2 s^-1. And the relative growth rate was highest at a temperature of 15℃, salinity 35 psu, pH 9, and light intensity of 60 μmol photon m^-2 s^-1. As a result of this study, the method using the optimal conditions for the survival rate and relative growth rate is expected to be a practical test method that can complement the current method.

• Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.123-129
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• 2011

To determine whether rearing density affects the hypermelanosis on the blind side (ambicoloration) of olive flounders Paralichthys olivaceus, we reared fry with an unpigmented non-eyed (blind) side in duplicate at densities of 150 individuals/$m^2$ (commercial production density: control) and 450 individuals/$m^2$ (high density group) for 90 days in 1-t dark-green fiberglass reinforced plastics (FRP) tank. We recorded feed intake, feed conversion efficiency (FE), growth and survival, and measured the ratios of staining blind-side area (staining area) and ambicolored fish every 30 days. Daily feed intake (DFI), feed conversion efficiency (FE), growth rate, condition factors, and survival rate were calculated at the end of the experiment. Although the FE was higher in the high-density compared to the control, the two density groups showed similar feed intakes, growth, and survival. The ratio of staining area as well as the ratio of ambicolored fish significantly were significantly higher in the high-density group than in the control from days 30 to 60, but significantly increased and evened out by the end of the experiment (P<0.05). In conclusion, we determined that rearing density is not the main cause of the blind-side hypermelanosis, but found that increasing the rearing density can accelerate the ambicoloration in olive flounders.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.1
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• pp.30-37
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• 1991

This experiment was conducted to determine optimal sowing date and method of Italian ryegrass(Lo1iuwr wzultiflorum. Tetrone) in paddy of Gyeong Nam area. Treatments given were four sowing dates(Sep. 30, Oct. 10, Oct. 20 and Oct. 30) and four sowing methods (broadcasting on tillage ridging, broadcasting on zerotillage ridging, boundless broadcasting and alternated drilling). The characteristics of growth, winter survival, yield(fresh and dry matter) and nutr~ent quality were observed. The results obtained are summarized as follows: 1. Winter survival and yield components such as plant height, and number of stem were the highest due to higher survival tillers at the sown time of Sep. 30(p<. 05). 2. Plants sown on Sep. 30 showed the highest fresh and dry matter yield. Yield was decreased as delaying the date of sowing. Fresh and dry matter yield sown on Oct. 10, were obtained 7600 and 1100 kg, respectively, aftenvardly sign~ficantly decreased(p< .05). 3. Effect of sowing time and method on chemical composition were not recognized. 4. Winter surviva: sown on boundless-broadcasting was lower(p<. 05) than those of sown on broadcasting on ridging and alternated-drilling. 5. Fresh and dry matter y~elds were the highest when sown on broadcasting on tillage ridging but that of sown on houndless-broadcasting was relatively low. 6. The growth and forage yield were enhanced by sowing up to Oct. 10 and by sown on broadcasting on ridging (tillage or zerotillage).

• Journal of The Korean Society of Grassland and Forage Science
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• v.1 no.1
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• pp.2-9
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• 1978

A review of factors influencing grass and clover establishment, survival and yield at oversowing was made from the experimental results of home and abroad. The following conclusions are considered: (1) The existing vegetation present at oversowing appeared to be the most critical factor reducing establishment and survival of grass. Therefore, it is essential to check competition from the native vegetation before oversowing. (2) Although lime had comparatively little effect on yield of grassland, the general effect of lime should be more emphasized under our acid soil conditions to promote the availability of all the essential elements and the growth of microorganisms, and to reduce the toxic effects of nutrients. One to two tons of lime per ha at oversowing would be useful. (3) Phosphorus is one of the nutrients most generally deficient in grassland soils of Korea, consequently, this nutrients applied at oversowing is very effective. Application as much as 200kg of phosphorus per ha would be essential. (4) The effect of nitrogen on the establishment and survival of grass depends on the amount and density of the herbage present. The use of nitrogen in dense herbage adversely affected grass establishment and survival, possible because the fertilizer stimulated the growth of the eisting herbage. Around 40kg of nitrogen per ha may be enough at oversowing (5) Potassium is not as universally deficient in soils of native grassland as phosphorus. Therefore, it cannot be over-emphasized at oversowing. Studies determinig the optimum amount of potassium at of oersowing are needed.

• Journal of Applied Biological Chemistry
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• v.56 no.3
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• pp.165-170
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• 2013

The SCO3388 gene from Streptomyces coelicolor is homologous to tmrB, the tunicamycin resistance gene of Bacillus subtilis. The SCO3388-inactivation strain (SY-tbl-1) was generated by replacing SCO3388 with thiostrepton resistance gene. Spores of S. coelicolor derivatives were prepared on mannitol-soy flour (MS) agar on which SY-tbl-1 displayed no significant defect in growth and development. When plated on R4 agar, spores of SYtbl-1 displayed retardation in growth and sporulation, whereas its mycelium gave rise to normal growth. Thus, SCO3388 is suggested to be involved in the dormant spore germination. Expression of SCO3388 under the ermE1 promoter restored but only partially the ability to sporulate in SY-tbl-1. Neither SY-tbl-1 nor SY-tbl-1/ermE1p-SCO3388 showed a difference in tunicamycin resistance to the wild type whereas, interestingly, the introduction of ermE1p-SCO3388 dramatically enhanced spore survival to heat and detergent treatments, suggesting that SCO3388 might play a role in the maintenance of spore cell wall integrity.

• Journal of Forest and Environmental Science
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• v.38 no.4
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• pp.249-255
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• 2022

The study was conducted to establish a method for the proliferation of hybrid poplar (P. alba × P. glandulosa) clone Bongwha1, an excellent biomass species. It was found that to collect the cuttings of Bonghwa1, it was necessary to use the main stem rather than the axillary branch. Stem growth by green-wood cuttings showed a tendency to decrease as the length of the collected cuttings increased, but the survival rate was low. Therefore, modified leafy stem cutting was attempted to increase the survival rate of the cuttings. In the modified leafy stem cutting method, 4 leaves were included in the cuttings, and especially, cuttings were performed using cuttings containing 2-4 cm xylem parts. Leafy stem cutting increased root growth and the number of stems, as well as the survival rate of hybrid poplar clone Bongwha1 compared to green-wood cuttings. The root growth of the leafy stem cutting poplar was better as there was more xylem part. Using two-year-old nursery stocks, the leafy stem cutting was used to produce about 66 cuttings. This study is expected to contribute to the mass propagation of high-quality nursery stocks.