• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.6
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• pp.478-484
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• 2004

On 11 June 1991, eggs from the brood stock of small yellow croaker (Larimichthys polyactis) were artificially fertilized using the standard dry method and were hatched. Each of the fertilized eggs (1.1-1.2 mm in diameter) had an oil globule and was transparent and buoyant. The fertilized eggs hatched in a range of water temperatures $(17.5-20.3^{\circ}C)$ 44 hrs after fertilization. The total lengths of the newly hatched larvae were 3.1-3.3 mm, and these hatchlings had 31 myotomes (10+21). Melanophores and yellow-brown chromatophores were concentrated on the head, at the ventral part of the yolk, and in the middle of the tail. Four days after hatching, the larvae completely absorbed the yolk and became flexions of 5.1-5.5 mm in total length. Fifteen days after hatching, one spine (the anterior tip of the maxillary) appeared in the upper jaw and three spines developed at the upper parts of the eyes and on the posterior part of the head. At this stage, the larvae were approximately 8.3 mm long. Thirty-nine days after hatching, juveniles (1.9-3.4 mm in total length) had a pointed tail fin. By 66 days after hatching, the juvenile fish (about 4.0-6.5 mm in total length) were similar to adult fish in body shape. The larvae of L. polyactis could be distinguished from those of L. croacea by two distinct characteristics: the large number of vertebrae (28-29), and a relatively small bony ridge on the occipital region of the head.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.4
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• pp.179-186
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• 1974

The followings are some results obtained from a series of experiments for the culture of eels from the elver stage in the laboratory from April 1973 to June 1974. 1. The optimum temperature turned out as 30t in the early stage culture. 2. The exponential curve of growth rate for a ten day period at the temperature between $20^{\circ}C$ and $30^{\circ}C$ was represented by the following equation: $$R=0.0056296\;T^{1.80740}$$ 3. The elvers and small eels that were kept improperly for a long time before this experiment also showed the same growth rate, compared with other healthful eels captured directly from the estuarine areas. 4. Those that showed retarded growth among a group of eels during the culture recovered the normal growth rate if graded out and kept in the other aquarium. 5. Feeding rate was not affected when the content of ammonia was less than 5 ppm, but it decreased by half when the content exceeds 6 ppm. 6, The elimination of fecal stuffs and uneaten dispersed feed was very important for the maintaining the water in quality.

• Fisheries and Aquatic Sciences
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• v.17 no.3
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• pp.319-324
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• 2014

An 8 weeks feeding trial was carried out to evaluate the effects of dietary microbial phytase (P) supplementation on nutrient digestibility, and body composition in juvenile olive flounder Paralichthys olivaceus fed soybean meal-based diets. Seven experimental diets were formulated to be isonitrogenous and isocaloric to contain 50.0% crude protein (CP) and 16.7 kJ of available energy/g with or without dietary phytase supplementation. White fish meal (FM) provided 92.4% of the total protein in the basal diet ($S_0$), in the other 6 diets, 30% or 40% FM protein was replaced by soybean meal: 70% FM + 30% soybean meal ($S_{30}$); 70% FM + 30% SM + 1000 U phytase/kg diet ($S_{30}P_{1000}$); 70% FM + 30% SM + 2000 U phytase/kg diet ($S_{30}P_{2000}$); 60% FM + 40% SM ($S_{40}$); 60% FM + 40% SM + 1000 U phytase/kg diet ($S_{40}P_{1000}$); and 60% FM + 40% SM + 2000 U phytase/kg diet ($S_{40}P_{2000}$). After two weeks of the conditioning period, triplicate groups of 25 fish initially averaging $6.15{\pm}0.04g$ ($mean{\pm}S.D.$) were randomly distributed into the aquarium and were fed one of the experimental diets for 8 weeks. After feeding trial, supplementation of phytase significantly improved the apparent digestibility coefficients of phosphorus in flounder diets (P<0.05) containing 30% and 40% soybean meal regardless the levels. However, phytase had no significant influence on growth performance and whole body composition of fish. Based on the experimental results, we conclude that dietary supplementation of phytase could improve the apparent digestibility coefficient of phosphorus in olive flounder.

• Korean Journal of Environmental Biology
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• v.25 no.4
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• pp.378-384
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• 2007

Some of ecological factors and the early life history of endangered freshwater fish, Pseusobagrus brevicorpus, were investigated to proliferate artificially and to restore the population by release seedlings. The density of population in restricted area by small scale dam was 1.25 ind. $m^{-2}$, and the low capacity for reproduction having 200$\sim$250 eggs ind$^{-1}$. were thought to be a reason of this endangered situation. From the result of induction of natural spawning in aquarium after hormone injection it was considered that the spawning substrate would be aquatic plants with slender branches. The hatching was observed after 50 hrs after fertilization and the larvae showed aggressive behavior. Yolk was almost absorbed 3 days after hatching, and the larvae shaped tad-pole grew up to fry after 30 days. We discussed on the strategies for conservation of this species according to those results from investigation on ecology and early life history.

• Journal of Food Hygiene and Safety
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• v.17 no.4
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• pp.206-209
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• 2002

From February through March 2002, sixteen rockfishes representing three species were collected from Oregon Coast Aquarium and Newport fish market and examined far nematodes. During this study, a total of 157 Anisakis type larvae were recovered from Sebastes spp. and parasitized for an average infection prevalence of 50.0%. The yellowtail rockfish, S. flavidus, darkblotched rockfish, S. crameri, and canary rockfish, S. pinniger examined were infected with 110 Anisakis simplex larva, 30 Contracaecum spp. larva and 17 Pseudoterranova decipiens larva. Of the rockfishes examined, 75.0% carried Sebastes crameri, and 12.5% S. flavidus and S. crameri, respectively. The sites of infection far Anisakis type larvae were the intestine, omentum, and stomach walls. A. simplex larvae infected 60.0% on S. crameri and 33.3% on S.flavidus and S. pinniger respectively. The prevalence of Contracaecum sp. larvae and Pseudoterranova decipiens larvae on S. pinniger was 33.3%. The intensities of A. simplex larvae ranged from 1 to 87 in S. flavidus, S. crameri, and S. pinniger. The intensity of Contracaecum spp. larvae and P. decipiens larvae ranged from 0 to 30 in S. pinniger.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.810-817
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• 2014

Two consecutive feeding trials were conducted to evaluate the effects of extruded pellet (EP) and raw fish-based moist pellet (MP) in the juvenile (experiment I) and sub-adult (experiment II) stages of olive flounder, Paralichthys olivaceus. The fish were distributed randomly to three aquarium tanks, as a group of 1,200 fish (initial mean weight $13.5{\pm}1.76g$) in experiment I, and as a group of 390 fish (initial mean weight $385{\pm}15.3g$) in experiment II. In experiment I, the weight gain, specific growth rate, feed efficiency, protein efficiency ratio, and survival of fish fed EP were all significantly higher than those of fish fed MP. In experiment II, no significant differences were observed in weight gain, specific growth rate and survival between the EP and MP groups. However, the feed efficiency and protein efficiency ratios of fish fed EP were significantly higher than those of fish fed MP. The results of this study indicate that EP could be developed to replace MP for market size production of olive flounder without any adverse effects on the growth performance. The dietary formulation used in this study could be used as an appropriate feed for olive flounder.

• Journal of Fisheries and Marine Sciences Education
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• v.23 no.3
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• pp.461-467
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• 2011

This experiment was conducted to determine the each level of a newly developed squid liver powder (SLP) as a dietary protein source replacing fish meal (FM) in juvenile flounder. A diet excluding SLP (FM diet) and a commercial diet were two control diets. Six experimental diets were formulated to replace FM with three types of SLP at 5 and 10% level, respectively (SLP-A5, SLP-A10, SLP-B5, SLP-B10, SLP-C5, SLP-C10). Prior to the start of a feeding trial, fish were fed the commercial diet for 1 week to adjust to the experimental conditions. Fish with average weight of $22.8{\pm}0.40g$ ($mean{\pm}SD$), were randomly distributed to each aquarium as groups of 20 fish and fed the experimental diets in triplicate at satiation for 8 weeks. After 8 weeks, weight gain and specific growth rate of fish fed SLP-C10 was lower than those of fish fed FM diet and SLP-B5. Meanwhile, no significant difference was observed in WG and SGR among fish fed diets excluding SLP-C10. Feed efficiency (FE) and protein efficiency ratio (PER) of fish fed each level of three types of SLP were not different from those of fish fed FM diet. However, fish fed SLP-C5 and SLP-C10 has lower FE and PER than those of fish fed a commercial diet, SLP-A5 and SLP-B5. Therefore, these results indicate clearly that dietary SLP-B could be a good protein source to develop inexpensive commercial diet in juvenile flounder.

• Fire Science and Engineering
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• v.28 no.2
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• pp.91-97
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• 2014

New types of fire accidents appear or the existing types disappeared because of rapidly changing society. We proposed a methodology of extracting new nouns from fire investigation data each of which is an accident report producted by fire investigators. The new nouns could be used in modifying the existing categories for classifying fire accidents. We analysed morphology of the product names and the ignition summaries using the proposed method for the fire accidents classified as the etc sub-category of the category of equipments involved in ignition. In this paper, we found "dryer" as a new sub-category of the agricultural equipment category and "boiler" in the seasonal appliance category from the product names of the fire accidents. We also extracted the new input keywords of "aquarium" and "monitor" in the commercial facilities category and the video, audio apparatus category from the ignition summaries respectively. Using the four subcategories, we reclassified 548 (14.39%) of 3,808 fire accidents assigned to the etc sub-category.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.709-716
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• 2011

To investigate the distribution and migrations of sea turtles occurring in Korean waters, an adult female green sea turtle Chelonia mydas was tagged with a satellite transmitter and released at Busan in October 2009. The confirmation was made for the first time that the released green sea turtle migrated back to Korea after visiting Jeju Island and Japan for approximately 9 months. The green sea turtle spent the winter in Jeju and Japan because of low water temperatures in the East Sea and South Sea during winter months, which were not suitable for turtle survival. Compared with an immature green sea turtle that was released at Jeju Island, the adult green showed a markedly different migration pattern, suggesting that juvenile and adult greens move differently because of their peculiar life cycle and their stage of maturity, in addition to responses to temperature changes. Additional satellite tracking with increased representation of species, sexes and sizes of turtles, and regions is required to gather information on the distribution and movements of sea turtles in Korean waters.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.496-498
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• 2013

Smartphone is becoming popular from younger generation to old generation because of its convenience. Generalizing use of smartphone, it was being developed and released for education application from based on PC to smartphone. in this paper, this application was designed and developed an helpful and enjoyable application for those who very interested child education. in this paper, suggestion of the propose of education is provided on service various contetns. The children can do implement information about organism characters living in sea just selected them they want without going to sea and aquarium whenever they want. this application is implemented that children also can be relearning the organism characters by quiz that already learned them before, and developing artistic sense, creativity and imagination by coloring exercise.