• 한국수산과학회지
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• 제44권3호
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• pp.243-250
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• 2011

The effects of food, temperature, salinity, and rearing density on the survival and growth of the swimming crab Portunus trituberculatus, were studied. With regard to food, the larval survival rate to zoea IV was the highest (53.9%) in the mixed feed group (rotifers+ Artemia), followed, in order, by the rotifer, commercial feed, and Artemia groups. The growth of young crabs reared on different diets was the highest in group VI. The survival rate to zoea II at 20 to $30^{\circ}C$ ranged between 77.2% and 83.1%, and was the highest for crab I (17.3%) at $25^{\circ}C$. When young crabs were cultured individually at four different temperatures (20, 25, 30, and $35^{\circ}C$), the growth did not differ significantly at 25 to $30^{\circ}C$, but was higher than at $20^{\circ}C$. The survival rate of larvae to crab I was 12.7 and 11.4% at 25 and 28 psu, respectively, while all of the larvae died at 15 psu. For young crabs, there was no significant difference in growth and survival from 20 to 30 psu. The survival rate decreased with increasing rearing density from zoea I to crab I. Each molting cycle took 1 month from crab I to VIII. Subsequently, the interval increased with growth. The mean body weight of crab XV after 24 months was $428.05{\pm}57.63\;g$.

• Plant Resources
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• 제1권1호
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• pp.38-42
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• 1998

One of the most attractive short-term possibilities for increasing freezing tolerance of winter crops may be the application of chemicals. This research was conducted to determine the effect of two plant growth regulators. Terpal-C and Cerone on freezing tolerance and winter survival of canola. Three cultivars were planted on the michigan state University Agronimy Farm at East Lansing. MI. on Sept. 10. 1992 and 1993 Chemicals were applied to one-month-old plants when they reached the 5 leaf stage. Ion leakage tests for freezing tolerance were conducted before and after chemical treatment. Winter survival was evaluated by counting the plant standing in the fall and spring. Neither of the chemicals. Terpal-C. inhibited natural cold hardening.

• 한국환경생태학회지
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• 제29권4호
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• pp.533-538
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• 2015

우리는 염분농도가 맹꽁이 초기발생과정에 미치는 영향을 알아보고자 실시하였다. 연구는 2013년 6월에 제주지역 해안가에서 산란하는 맹꽁이 포접쌍의 알을 가지고 실시하였다. 염분농도는 0, 1, 3, 5, 7‰로 하여 알에서 외부아가미가 닫힐 때까지 생존여부와 생장을 관찰하였다. 또 다른 실험은 내부아가미 단계인 올챙이를 0, 1, 3, 5, 7‰의 염분농도에 넣어 생존율과 생장률을 관찰하여 두 실험결과를 비교하였다. 실험결과 알 - 외부아가미 단계에서는 3‰에서 대조군과 유의한 차이가 없이 생존하였으나 5‰에서는 생존율이 낮게 나타났다. 또한 7‰에서는 모든 알이 죽는 것으로 나타나 염분농도가 5‰이상에서는 맹꽁이 초기발생에 생존 영향을 끼치는 것으로 나타났다. 내부아가미 단계에서의 유생들은 5‰까지는 대조군과 유의한 차이가 없었으나 7‰에서는 생존율이 감소하였다. 생장률인 경우도 염분의 농도가 높아질수록 생장이 느려지고 있었고 외부아가미 단계 및 내부아가미 단계 모두 5‰에서 생장률이 대조군과 유의하게 감소하는 것으로 나타나고 있었다. 이번 연구 결과 염분의 농도가 높을수록 맹꽁이 유생의 생존과 생장에 영향을 받는다는 것을 알 수 있었으며, 해안지역 개발에 따른 부작용인 맹꽁이의 감소에 대한 종 보존에 대비 할 수 있을 것으로 판단된다.

• 농업과학연구
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• 제51권1호
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• pp.25-39
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• 2024

This study aimed to determine a method for restoring grasslands to forests in mountainous areas. The study was conducted in an area damaged by trampling due to construction activity and herding. Additionally, there were concerns of hindered tree growth due to the alpine region climate, characterized by the low temperatures, drying, and strong winds. Therefore, forest restoration treatments such as tillage, furrow, and shading were performed to improve growth conditions. From July 2021 to April 2023, soil temperature and moisture were monitored for each treatment plot, and changes in the initial growth and survival rate of Abies holophylla were investigated. Both soil temperature and soil moisture showed significantly higher values during the four seasons in the grassland-furrow treatment plot (p < 0.05). Compared to the grassland-control plot, the average soil temperature in winter was as high as 1.1℃, and the soil moisture in summer was as high as 20.3%. Additionally, the survival rate and relative growth rate were the largest in the grassland-furrow treatment plot. The survival rate was 87.5%, the relative growth rate in terms of height was 0.013, and the relative growth rate in terms of diameter at root collar was 0.023, indicating that furrow treatment had a positive effect on the initial survival and growth of seedlings. These results suggest that furrow treatment may be an appropriate restoration method when implementing forest restoration projects in areas where tree growth is challenged.

• 한국양식학회지
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• 제14권1호
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• pp.29-33
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• 2001

Total length and body weight of grey mullet were 6.4cm and 2.1g, respectively at the beginning of the experiment. After 60 days of rearing, body weight of the mullet(363%) was significantly higher in freshwater group than that (187%) in seawater group. However, the condition factor showed no significant differences between seawater (9.0%) and freshwater (8.8%) groups. Survival of the mullet was 98.3% and 64.3% in seawater and freshwater groups, respectively.

• 현장농수산연구지
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• 제20권1호
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• pp.97-105
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• 2018

돌기해삼의 성장과 생존에 가장 효과적이며 경제성이 있는 사육밀도를 조사하였는데 체중 성장은 250, 350과 500 개체/m2 실험구에서 각각 31.9±18.3g, 26.8±14.6g과 21.5±16.4g으로 성장하였고, 실험 시작할 때 보다 250마리/m² 실험구는 약 5.1배, 350마리/m² 실험구는 약 4.3배 및 500마리/m² 실험구에서는 3.5배의 성장을 보여 수용밀도가 낮을수록 빠른 성장을 보였다. 생존율은 250마리/m² 실험구는 50.1%로 가장 높게 나타났으며 350마리/m² 실험구는 47.6% 그리고 500마리/m² 실험구에서는 44.2%로 낮게 나타났다. 실험기간동안 성장과 생존율은 사육밀도가 낮을수록 높아지는 것으로 나타났으며 일정시기와 일정크기에 따른 선별이 필요할 것으로 판단된다.

• 환경생물
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• 제30권1호
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• pp.9-14
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• 2012

넓은 범위의 염분에 대한 망둑어 3종의 적응성을 파악하기 위하여 이들의 생존 및 성장에 대한 염분농도의 영향을 검토하였다. 두줄망둑은 0~33.6‰의 염분범위에서 유의한 생존율 차이가 없었고, 점망둑의 생존율은 염분농도 13.4‰ 이상에서 90% 이상을 나타내었으며, 3.4‰ 이하에서는 80% 이하로 유의하게 감소하였다. 또한, 날개망둑의 생존율은 염분농도 3.4‰ 이상에서 90% 이상을 나타내었으나, 담수에서는 87.5%로 유의한 감소가 관찰되었다. 두줄망둑은 염분농도 13.4 및 20.2‰에서 가장 높은 일일성장률은 나타냈고, 담수에서 유의한 감소가 관찰되었다. 점망둑의 일일성장률은 염분농도 20.2~33.6‰ 이상에서 가장 높았고, 10.1‰ 이하에서 가장 낮아 이들 사이의 유의한 차이를 나타냈다. 날개망둑의 일일성장률은 염분농도 10.1~27.4‰에서 가장 높았으나, 담수에서 유의한 감소가 나타났다. 이상의 결과는 3종의 망둑어, 특히 점망둑은 낮은 염분에 노출되었을 때, 그들의 생존 및 성장에 영향을 받는다는 것을 의미하고 있어 이들의 분포 및 개체수에 잠재적인 영향을 받을 수 있을 것으로 예상된다.

• Asian-Australasian Journal of Animal Sciences
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• 제14권10호
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• pp.1477-1482
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• 2001

Research in low cost feeds with high nutritional value and immunogenicity is important to reduce production cost and increase yields in the shrimp industry. In this study, immunostimulants of bacterial origin (peptidoglycan and lipopolysaccharides) and egg white were incorporated in shrimp diets as feed additives to determine the growth, survival and tolerance of Penaeus monodon to white spot syndrome virus (WSSV). Although the results obtained were not statistically significant (p>0.05) among the treatments, shrimp fed with bacterial additives and egg white showed higher weight gain, specific growth rate and survival than those fed on commercial shrimp diet. Shrimp fed with artificial diet showed 100% mortality when challenged with WSSV. However, shrimp fed on peptidoglycan supplemented diet had higher survival than their counterpart, whereas shrimp fed on egg white supplemented diet had a higher specific growth rate and better tolerance when challenged with WSSV. Further studies are required to determine the effectiveness and optimization of bacterial strains and egg white as feed additives to increase production and enhance the shrimp immune response to diseases.

• 한국패류학회지
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• 제28권4호
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• pp.293-303
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• 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.

• 한국환경과학회지
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• 제22권7호
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• pp.801-810
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• 2013

To improve the physical and chemical properties of the soil and increasing water-retaining property of the soil, Superabsorbent synthetic polymeric materials have been used. The experiment carried out from April to July 2012 after the influence evaluation of Superabsorbent synthetic polymeric materials to vines plant. The result shows that the study of Hedera japonica Tobler, the growth and the survival rates rank as media > hydroponic > superabsorbent synthetic polymers, and the growth and the survival rates are considerably pessimistic in the experiment of hydroponic and superabsorbent synthetic polymers. In the study of Trachelospermum asiaticum var. intermedium, the growth and the survival rates rank as hydroponic > media > superabsorbent synthetic polymers, the difference between the experiment of hydroponic and is very small and the survival rates are not very good in the experiment of superabsorbent synthetic polymers. In the study of Euonymus fortunei var. radicans Rehder,it is insignificantly difference among the different of planting based. Judging from these results, the differences are depending on the species of plants. The thesis holds that the characteristics of plant should be considered in plant cultivation and soil improvement in the future, and it is desirable to use the appropriate mixing ratio of soil in soil improvement as well.