• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.2
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• pp.144-149
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• 2018

The eggs are incubated for 18 days through the generator and incubated in the developing incubator. During the developmental period, the weight loss of the fetus is correlated with the ventricular formation, and the proper ventricular formation is also associated with the healthy embryonic hatching and the egg hatching rate. However, in the incubator period of the domestic hatchery, it is a reality to acquire the resultant side by the Iranian standard weight measurement with the experience of the hatchery and the person concerned and the development period without the apparatus for measuring the present weight. As a result, prevalence of early mortality, hunger and illness during hatching are frequent. Monitoring the reduction of weaning weight is crucial to obtaining chick quality and hatching performance with weight changes within the development machine. Water loss is different depending on the size of eggs, egg shell, and elder group. We can expect to increase the hatching rate by measuring the weight change in real time and optimizing the ventilation change accordingly. There is a need to develop a real-time measurement system that can control 10 to 13% reduction of the total weight during hatching. The system through this study is a way to check the one - time directly when moving the existing egg, and it is impossible to control the measurement of the fetal water evaporation within the development period. Unlike systems that do not affect the hatching rate, four load cells are connected in parallel on the Arduino sketch board and the AT-command command is used to connect the mobile phone and computer in real time. The communication speed of Bluetooth was set to 15200 to match the communication speed of Arduino and Hyper-terminal program. The real - time monitoring system was designed to visually check the change of the weight of the fetus in the artificial incubator. In this way, we aimed to improve the hatching rate and health condition of the hatching eggs.

• Journal of Aquaculture
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• v.2 no.2
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• pp.91-106
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• 1989

Chlorella has been used as a very useful food for rearing rotifer which is an important live food for early stages of fish and crustancean larvae. But Chlorella does not grow well in higher or lower temperature such as during summer or winter season in this country. Therefore, cooling or heating facilities are needed for Chlorella culture during summer or winter, but it costs too much for the commercial scale fish farmers. To solve this problem, the growth rates of 34 different species of phytoplanktons were examined at the various levels of temperatures, salinites and light intensities to select suitable species as the food for rotifers for summer and that for winter. After the suitable species were selected, growth comparisons of rotifer groups which were fed the selected species of phytoplanktons against rotifer group fed Chlorella as a control were done. Fatty acid compositions of the selected phytoplanktons and rotifer groups which were fed these selected phytoplanktons were examined. It was revealed that Nannnochioris oculata was optimum for rotifers in summer season and Phaeodactylum tricornutum was suitable for that in winter season. The optimum temperature, salinity and light intensity for former phytoplankton were $28^{\circ}C$, $33\%_{\circ}$ and 5,000 lux and those for later were $10^{\circ}C$, $30\%_{\circ}$ and 8,000 lux, respectively. In the higher temperature condition, the growth of N. oculata fed rotifer group was better than Chlorella ellipsoidea fed group. In the lower temperature condition, however, the growth of Chlorella fed rotifer group was slightly better than P. tricornutum fed group. Between two selected phytoplanktons, N. oculata has the highest content of linolenic acid (18 : 3 $\omega$ - 3, $\omega$ - 6) which is essential fatty acid for marine fish larvae. A rotifer group which was fed this plankton also showed the highest linolenic acid content among the other rotifer groups.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.1
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• pp.55-59
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• 2000

A specific and sensitive sandwich enzyme-immunoassay (EIA) using Avidin-Biotin complex was developed for the measurement of GTH II levels in pituitary content and pituitary cell culture medium of the rainbow trout-(Oncorhpchus mykiss). Biotin-salmon GTH II rabbit IgG (sefondary antibody) wai purified by a protein A sepharose affinity chromatography column and that was biotinylated by using Biotin-N-hydroxysuccinimide ofter (BNHS). Non-biotin salmon GTH II rabbit IgG (first antibody) was obtained only through a protein A sepharose affinity chromatography column. The assay was performed by the so-called 'sandwich' method using a microtiter plate, A dose-response curve was obtained between $0.12 to 125 ng/ml$ of salmon GTH II. The displacement curves for pituitary extraction and pituitary cell culture medium of testosterone-treated rainbow trout were Parallel to the standard curie. The intra-assay and inter-assay coefficients of variation (CV) were $8.2{\%} (N=5) and 12.5{\%} (N=6)$, respectively, This assay system was used to measure the amount of GTH II that accumulated in the culture medium of dispersed pituitary cells in testosterone-treated immature rainbow trout, The accumulation was increased with the amount or salmon gonadotropin-releasing hormone. GTH II values determined by the present method were well correlated with those determined by radioimmunoassay. As a result, this assay system was found to be suitable for the measurement of GTH II for pituitary extraction and pituitary culture medium in many salmonid fishes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.1
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• pp.51-56
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• 2001

Changes of gill tissue and body composition of grey mullet (Mugil cephalus) and Nile tilapia (Oreochromis niloticus) by the manipulation of salinity were observed in a recirculating rearing system. Salinity was increased from $0\%_{\circ}$ to $33\%_{\circ}$for 1 day and remained far 15days, thereafter salinity was decreased from $33\%_{\circ}$ to $0\%_{\circ{$ for 1 day and remained for other 15 days. Any morphological differences of gill lamella in grey mullet were not observed in seawater and freshwater. However, on day 2 in exposure to seawater, Nile tilapia showed the edema and bloodclot in gill lamella. In the case of grey mullet, mitochondria and tubular system of chloride cell were more densely packed according to the salinity increase. The whole body of grey mullet showed no significant differences in moisture content during experimental period. However, moisture content in whole body of the Nile tilapia was signincantly decreased when exposed to seawater. Protein content in whole body of grey mullet showed no significant difference between beginning and day 15 of the experiment.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.78-79
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• 2003

Effects of dietary lipid level and source (squid liver oil being rich in n-3 HUFA, soybean oil being rich in 18:2n-6, and linseed oil being rich in 18:3n-3) in fishmeal-based diet on growth and body composition of grower sunshine bass raised in seawater were investigated. Fifteen grower (an initial weight of 146.8$\pm$0.23 g) sunshine bass were randomly distributed into 27 of 250 L fiber reinforced plastic flow-through tanks. Fish were hand-fed to satiety twice daily for 6 days a week throughout the feeding trial. Survival was over 97% and not significantly affected by either dietary lipid level or lipid source (n-3 highly unusaturated fatty acid, HUFA). Weight gain of fish tended to improve with dietary n-3 HUFA level up to 2.9%, but sharply decreased at 3.5%. The best weight gain was obtained in fish fed the diet supplemented with 6% squid liver oil and 3% soybean oil. FER and PER were not significantly affected by either dietary lipid level or dietary lipid source. The lowest moisture content of the whole body was observed in fish fed the diet supplemented with 12% squid liver oil and highest for the diet supplemented with 9% linseed oil, respectively. Protein content of fish was not significantly affected by either dietary lipid level or dietary lipid source. However, lipid content of the whole fish tended to increase with an increase of either dietary lipid level or dietary n-3 HUFA level, except for fish fed the diet supplemented with 9% linseed oil. Ash content of fish fed the diet with no supplementation of oil was highest and lowest for the diet supplemented with 9% soybean oil, respectively. Significant differences in saturated fatty acids (16:0, 18:0 and 24:0), monoene (18:1n-9), 18:2n-6, 20:5n-3 and sum of n-3 HFUA of fish were observed. In considering these results, it could be concluded that supplementation of 9% oil combined with 6% squid liver oil and 3% soybean oil into fishmeal-based diet was the most recommendable for growth of grower sunshine bass raised in seawater.

• Journal of Aquaculture
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• v.7 no.4
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• pp.225-237
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• 1994

Survival and growth rates of flounder larvae fed rotifers and Artemia nauplii enriched by various bio-enrichment techniques were investigated. Enriched materials used in the study were $12\omega-yeast$, 2 commercial emulsified oil and microparticulated products. $\omega-yeast$ were added with one kinds of oils (cuttlefish liver oil, sardine oil, Alaska pollock liver oil, linseed oil) at the level of $5\%,\;15\%\;and\;25\%$. The results are as follows: 1. The growth rate of rotifers cultured with $\omega-yeast$ added $15\%$ cuttlefish liver oil was the best among 12 kinds of $\omega-yeast$ and this performance was almost the same with that of rotifers fed on Chlorella. 2. Survival and growth rates of flounder larvae fed on rotifers and Artemia nauplii enriched with $\omega-yeast$ and the other commercial products were higher than that those of larvae cultured with only Chlorella and non-enriched Artemia. The optimum contents of the cuttlefish liver oil in $\omega-yeast$ for rotifers and Artemia enrichment were $15\%\;and\;25\%$, respectively. 3. Optimum enrichment time and supply amount of $\omega-yeast$ for Artemia nauplii were 6 hr., 1.5 g/g cyst, respectively.

• Korean Journal of Ichthyology
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• v.13 no.3
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• pp.173-180
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• 2001

The fertilized eggs of Hyporhampus sajori (Temminck et Schlegel) were collected on the shore of Youngil Bay, Phohang-shi, Korea, on May 27, 1991, and were hatched and reared in the laboratory to investigate osteological development of larvae and juveniles. The newly hatched larvae were 7.00~8.50 mm (mean 7.80 mm, n = 5) in total length (TL) and had an ossified cranium, visceral skeleton and shoulder girdle bones. At 8 days, the larvae had attained 10.07~14.75 mm (mean 13.07 mm, n = 5) in TL had elongated dentaries anteriorly, and their vertebral columns were posteriory ossified. At 14 days, the larvae had attained 17.62~19.35 mm (mean 19.20 mm, n = 5) in TL, had ossified pterygiophores, and 41 slender ribs on the vertbrae. At 16 days, the larvae were 18.90~24.72 mm (mean 23.00 mm, n = 5) in TL and had three ossified epurals. Ossification of the jaw bone and operculum of the newly hatched larvae, which was related to feeding and respiration was almost completed 37 days after hatching.

• The Korean Journal of Malacology
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• v.30 no.4
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• pp.343-351
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• 2014

We determined the effects of neuroactive compounds known as synthetic larval settlement inducers on the settlement of the Pacific oyster C. gigas pediveliger on the larval collector. Six types of the inducers, serotonin (5-HT), ${\gamma}$-amino butyric acid (GABA), L-3,4-dihydroxyphenylalanine (L-DOPA), norepinephrine, epinephrine and methyl bromide (MB) were tested. All the chemicals induced larval settlement, MB being the most effective with settlement rate of $42.7{\pm}2.7%$, followed by GABA ($35.4{\pm}2.0%$), 5-HT ($29.1{\pm}2.2%$), L-DOPA ($19.2{\pm}2.1%$), epinephrine ($15.2{\pm}0.9%$), and norepinephrine ($11.0{\pm}1.2%$). The chemicals ${\gamma}$-amino butyric acid and methyl bromide were also better in terms of settled density on the collector with their respective density of $1.97{\pm}1.42$ and $2.37{\pm}1.86ind/cm^2$, reminiscent of being most effective candidates for a larval settlement inducer in the oyster hatchery.

• Journal of Aquaculture
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• v.8 no.4
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• pp.317-326
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• 1995

In order to evaluate three species of diatoms as the live food sources for rearing larvae of sea urchin, Strongylocentrotus intermedius, six different feed experiments were conducted for 35 days. We measured sizes, survival rates on elapsed day after hatching and required days of each larval stages of sea urchin in the different feeding experiments. Sizes of the larvae of sea urchin cultured with Isochrysis + Chaetoceros, Isochrysis, Chaetoceros and Pavlova were $735{\mu}m$, $718{\mu}m$, $701{\mu}m$ and $642{\mu}m$, respectively. The highest daily growth rates of the larvae of sea urchin showed Isochrysis within 6 armed and Chaetoceros after 6 armed. Survival rates of the larvae of sea urchin cultured with Chaetoceros, Isochrysis + Chaetoceros, Isochrysis and Pavlova were $37.2\%,\;35.0\%,\;32.4\%,\;and\;18.4\%$, respectively. The required days from fertilization to the 8 armed (Senior) stage in the larvae of sea urchin, fed Chaetoceros, Isochrysis, Paviova, chaetocerost+pavlova, pavloua + Isochrysis and Isochrvsis + chaetoceros were 24, 27, 33, 28, 30 and 25 days, respectively.

• Journal of fish pathology
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• v.4 no.2
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• pp.79-85
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• 1991

In Feb., 1990 an epizootic disease to masu salmon fry, Oncorhynchus masou cultured at the hatchery of rainbow trout in Samchok, Kwangwon-do have broken out and induced high mortality over 70%. Externally, the diseased fish showed dark discoloration, abdominal distension with ascites, slight exophthalmus and fecal casts. Internally, the gill and the liver of diseased fish were edematous and pale, and the stomach of moribund fish contained the milkish fluid. Microscopically there was extensive necrosis of the hematopoietic tissue in kidney and spleen, and scattered necrosis of pancreas, liver and lateral muscle. Especially, the necrosis of lamina propria, muscle layer and tela submucosa in the digestive tract known as the typical signs associated with infectious hematopoietic necrosis virus was seen clearly.