• The Korean Journal of Pesticide Science
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• v.20 no.1
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• pp.47-55
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• 2016

The purpose of this study was to control root-knot nematode, Meloidogyne incognita on pumpkin seedling with 10%, 20% coffee ground compost and 1% plant velvet bean powder (plain skin bean, leopard skin bean, hole plant, bean pod). Among the root-knot nematode insecticide treatments, the velvet bean plant powder was the highest mortality rate with 83.2% in greenhouse condition. In addition, the root-knot nematode second juvenile mortality significantly increased with the lapse of processing time for each concentration of leopard skin velvet bean extract in vivo. After 24 hours, the mortality rate of root-knot nematode showed the highest at 1.2% and 2.4% of leopard skin velvet bean extract. The growth promoting effect of seedlings pumpkin, 20% of coffee ground compost treatments inhibited the growth of pumpkin seedlings and 1% the tiger pattern velvet beans powder was the most to promote the growth of pumpkin seedlings. However, the results indicated that the organic materials of velvet beans and coffee ground compost are expected to be able to effectively control the root-knot nematode and further studies will be needed for the concentration and application methods.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.2
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• pp.245-251
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• 1998

A 10-week feeding experiment was conducted to determine the influence of several minerals from dietary mineral premix on growth and body composition in juvenile Korean rockfish. Three replicate groups of fish Initially averaging 4.2 g were fed one of the ten experimental diets. Korean rockfish muscle and casein as protein sources were used in the basal diet, and deleted one of each mineral (P, Ca, Zn, Mg, Fe, K, Mn, Se or all) in the control mineral premix, Weight gain, feed efficiency and nutrient retention in fish fed the diet not containing mineral premix were significantly lower than those in fish fed other diets (P<0.01). Weight gain in fish fed the diets deleted each mineral (P, Ca, Zn, Hg, Fe, K, Mn or Se) was lower than that of control diet (P<0.01), Feed efficiency and protein retention in fish fed the diets deleted each of P, Ca, Zn or Mn were lower than those ot control diet (P<0.01). Daily feed intake and lipid retention were not affected by dietary mineral premixes ( P>0.01). Proximate analysis and mineral contents in the whole body, muscle, liver or bone of fish fed the diets deleted each mineral were not different to control diet ( P>0.01). The data obtained in this study indicate that each of the P, Ca, Zn, Mg, Fe, K, Mn or Se is essential for normal growth of Korean rockfish.

• Fisheries and Aquatic Sciences
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• v.19 no.9
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• pp.39.1-39.9
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• 2016

Magnesium hydrogen phosphate (MHP, $MgHPO_4$) recovered from swine manure was prepared as an alternative phosphorus (P) source. Conventional P additives, monocalcium phosphate (MCP), dicalcium phosphate (DCP), and tricalcium phosphate (TCP) were compared with the MHP in terms of growth and P availability by juvenile carp Cyprinus carpio. A basal diet as a negative control was prepared using practical feed ingredients without P supplementation to which four supplemental P sources were added at the level of 2%. Five groups of 450 fish having mean body weight of 6.5 g following 24 h fasting after 2 weeks of adaptation period were randomly distributed into each of 15 tanks (30 fish/tank). Fish were hand-fed to apparent satiety twice a day for 9 weeks. Fish fed the MHP had weight gain (WG), feed conversion ratio (FCR), protein efficiency ratio (PER), and specific growth rate (SGR) comparable to those fed the MCP. Those values of both the MHP and MCP groups were significantly different (p < 0.05) from the other groups. Fish groups fed control and the TCP showed the lowest WG, PER, and SGR and the highest FCR among treatments. No fish were died among treatments during the experimental period. Fish fed control and the TCP showed hematocrit and hemoglobin significantly lower (p < 0.05) than fish fed the MHP. The lowest inorganic P (Pi) in plasma was found in the control group. Even though Pi was not significantly different (p > 0.05) from other phosphate groups, fish fed the MCP and MHP retained higher P in whole body than the other groups. P availability was determined to be 93.2, 62.4, 6.1, and 98.0% for MCP, DCP, TCP, and MHP, respectively. The present results suggested that the MHP recovered from wastewater stream could be used as an alternative P source in carp diet.

• Journal of Aquaculture
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• v.16 no.3
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• pp.129-134
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• 2003

Spawning induction and early growth of the sea urchin, Strongylocentrotus intermedius were studied with the purpose of artificial seedling production. Gonadosomatic index(GSI) of the sea urchin showed the highest value in October, and rapidly decreased in December. It means that October and November is the peak of spawning season of the sea urchin in the latitude. Spawning induction by injection of potassium chloride solution in October has showed 44.0~100.0% reaction rate, and were produced 6,300$\times$10$^4$ eggs. Spawned eggs have shown the fertilization rate of 92.3~98.2% and the hatching rate of 78.2~87.0%. The metamorphosis of larvae after hatching in the seawater temperature of 13.7~17.1$^{\circ}C$ resulted in early eight-armed larvae in 13 days and late eight-armed larvae in 20 days. The collection of progenies was possible in 24~25 days after hatching and collection rate was 18.5~26.1% (mean 22.3%). Test diameter immediately after collection had a mean 350 ${\mu}{\textrm}{m}$. Survival rate and test diameter of juvenile sea urchin after collection were 58.5%, 1.32 mm in 30 days, 27.7%, 3.82 mm in 92 days and 15.6%, 11.70 mm in 181 days, respectively.

• Journal of Aquaculture
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• v.10 no.4
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• pp.417-424
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• 1997

This study was carried out to investigate the effects of experimental formulated diets, commercial diets and natural diet(dried Undaria) on growth and body composition of Haliotis discus hannai. Experimental diets was formulated to provide 34.1% protein and 7.5% lipid, and prepared by different $CaCl_2$ concentration (5, 10 and 15%) and dipping time (10, 20 and 60 second) in solution. The juvenile abalone average weighing 0.3g were distributed in a flow-through aquarium system using a cmpletely randomized desing with 13 diets and 3 replictes per diet (50 abalone/tank), and fed diets for 17 weeks. The abalone fed the time nine experimental formulated diets and two commercial diets showed better growth performance than that of natural diets. No significant differences were found among abalone fed the experimental diets and commercial diets in survival rate, weight gain, soft body weight and soft body composition (P>0.05).

• Korean Journal of Plant Resources
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• v.25 no.1
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• pp.123-131
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• 2012

This study analyzed on the characteristics of community structure, species composition, population conditions and annual mean radial growth of Taxus cuspidata in the subalpine zone of the Seoraksan, Deokyusan, and Hallasan National Parks. Deokyusan and Hallasan sites had three layers of stratification structure without tree layer in it and four layer in Seoraksan site. The major dominant species in the order of importance value were as follows: T. cuspidata, Acer tschonoskii var. rubripes, Quercus mongolica, Abies koreana and Sorbus commixta. The trees (> 5 cm DBH) of T. cuspidata were extremely high with 986.0 individuals/ha at the Hallasan site. Average DBH class were 42.0 cm at the Hallasan site and mainly showed large class. The populations of seedlings and saplings with 357.3 individuals/ha, and juvenile with 128.6 individuals/ha, as a succession tree, were found to be the highest at the Hallasan site. In the size frequency distribution, the populations of T. cuspidata in Mt. Halla site showed a reverse J-shaped curve and it was estimated that T. cuspidata community of this site might be maintained continuously as a stable state like present state. Annual mean radial growth of T. cuspidata populations at Seoraksan, Deokyusan, and Hallasan sites showed up as 1.27 mm/year, 0.93 mm/year and 0.89 mm/year respectively.

• Journal of Marine Life Science
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• v.6 no.2
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• pp.106-116
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• 2021

To secure basic data by monitoring the growth of salmon (Oncorhynchus keta) released to the Taehwa River. After discharge, the characteristics of the young salmon distribution and migration rate habitat were investigated for two years. A total of 4 points [Sunbawi bridge (St.1), Guyeong bridge (St.2), Samho bridge (St.3), and Myeongchon bridge (St.4)] were investigated. The survey of 2017 indicating an increase of 10 mm in average length and 0.8 g in average weight, and the survey of 2018 indicating an increase of 10 mm in average length and 0.5 g in average weight. Among 39 species, 10 insectivorous and 12 omnivorous, are believed to compete with young salmon for food. 6, 5, 6 and 8 predatory fish species has emerged at each site, respectively. According to this study, it is believed that St.1 and St.2 points are more proper as discharge location of young salmon because these two points have less varied in depth, flow rate, salt concentration etc. In addition, it is thought that the night or dawn time in early January is the best discharge time of young salmon fish because predatory fish such as Korean piscivorous chub and bass etc. does not eat food actively at that time.

• Fisheries and Aquatic Sciences
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• v.26 no.12
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• pp.726-737
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• 2023

Piperine, the main bioactive component of black pepper (Piper nigrum Linn.), has anti-inflammatory, antifungal, and antibacterial properties. This study evaluated the supplemental effects of piperine or black pepper on innate immunity, growth, feed utilization efficiency, and intestinal morphology in red seabream (Pagrus major). Six experimental diets were formulated, supplementing piperine at 0.0, 0.25, 0.5, 1.0, and 2.0 g/kg levels (Con, P25, P50, P100, and P200) or 1.0 g/kg black pepper (BP100). Juvenile fish (7.6 ± 0.1 g) were randomly stocked into 18 circular tanks (220 L), including 30 fish per tank. Each diet was randomly assigned to triplicate groups, and the feeding trial was conducted for 8 weeks. The results showed that final body weight, specific growth rate, weight gain, and feed utilization efficiency were significantly improved (p < 0.05) when piperine was supplemented into diets at 0.25-2.0 g/kg levels compared to the Con group. Compared to the Con diet, condition factor was significantly increased (p < 0.05) in fish fed with dietary piperine at 0.25-2.0 g/kg or BP100 diet. Serum myeloperoxidase activity was increased (p < 0.05) in P25 and P100 groups and antiprotease activity was increased (p < 0.05) in P100 group compared to the Con group. Significantly higher (p < 0.05) lysozyme activity was observed in P50, P100, P200 and BP100 groups, while total immunoglobulin level was increased in P50, P100 and BP100 groups than Con group. Superoxide dismutase activity was increased (p < 0.05) by dietary piperine at 0.25-2.0 g/kg levels and BP100 diet compared to Con diet. Plasma cholesterol was significantly lower (p < 0.05) in fish fed with piperine (0.5-2.0 g/kg) or BP100 compared to the Con diet. Compared to the Con diet significantly longer (p < 0.05) intestinal villi were observed in fish fed with piperine at 0.25-1.0 g/kg levels, and higher goblet cell count was observed in P25 and BP100 groups. Dietary inclusion of piperine would be a potent immunostimulant in fish diet and the optimum supplementation level would be 0.25-1.0 g/kg.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.3
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• pp.553-563
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• 2013

This study was conducted to evaluate the quality characteristics (proximate composition, fatty acids, amino acids and sensory properties) of whole body and dorsal muscle in olive flounder, which is switch size from juvenile to growing fed extruded pellets (EP) and raw fish-based moist pellet (MP) for 9 months. Sample was collected at 5 and 9 months to compare with those of EP and MP. Whole body crude protein of fish fed EP at 9 months was significantly higher than that of fish fed MP (P<0.05). Linolenic acid(18:3) and n-6/n-3 ratio in dorsal muscle of fish fed EP were significantly higher than those of fish fed MP (P<0.05). No significant differences were observed in the results of the flavor, color, taste and texture of the muscle of the fish fed EP compared to those fed MP (P>0.05). Based on the experimental results, we concluded that olive flounder cultured with EP is not inferior to those fed MP for quality characteristics of whole body and muscle.

• Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.299-303
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• 2012

Barbel structure and regenerated barbel length in the juvenile Chinese longsnout catfish Leiocassis longirostris (G$\ddot{u}$nther), were evaluated. The barbles consisted of an epidermis, a dermis, and a central rod. The epidermis harbored taste buds, granular cells and epidermal cells. The taste buds were basophilic and situated along the distal portion of the epidermis. The dermis was composed of loose connective tissue containing blood vessels pigment cells. The innermost central region was cartilage enclosed within layers of muscle layers. After 30 days, the regenerated barbel length measured $0.92{\pm}0.404mm$ at $15^{\circ}C$ (regenerated growth curve: y = 0.5085x + 4.0678, $r^2$ = 0.9654, where y is regenerated length and x is experimental period in days), $1.88{\pm}0.521mm$ at $20^{\circ}C$ (y = 0.1806x + 4.808, $r^2$ = 0.9822), and $6.44{\pm}0.751mm$ at $25^{\circ}C$ (y = 0.0914x + 4.9918, $r^2$ = 0.9944). Fifteen days after amputation, the regenerated length was significantly longer at $25^{\circ}C$ than at 15 or $20^{\circ}C$ (P < 0.05). The barbels of the Chinese longsnout catfish was the tender and flexible type, and our experimental findings provide evidence of temperature-dependent regeneration. Additional investigation of the behavior and physiology of the Chinese longsnout catfish is needed, particularly histological studies of regenerated barbels and the measurements of the numbers of taste buds per barbel under various environmental conditions.