• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.2
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• pp.130-134
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• 2002

The ovary of the rockfish, Sebastes inermis was cystovarian condition and consists of numerous ovarian lobules. Previtellogenic oocytes were embedded in the connective tissue of the ovarian lobules. As the oocytes grows, it protruded into the ovarian cavity and form grapes cluster-like structure with egg stalk-like structure. Yolk granules and zona radiata were not observed in the embedded early oocytes about 20 $\mu$m in diameter. In the oocytes about 80 $\mu$m in diameter, yolk granules with electron dense were abundant in the ooplasm near the egg stalk-like structure. However, pinocytosis was not obsened in the pore canal system of the zona radiata. In this stage, microfilaments, developed endoplasmic reticula, tubular mitochondria, granular materials with low electron density and active multivesicular bodies were observed in the egg stalk-like structure. This results suggest that the egg stalk-like structure of the rockfish are related with the oocyte attachment and exogenous vitellogenesis of the intial vitellogenic oocyte.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.10
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• pp.1458-1463
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• 2016

A 42-d study with 384 Hy-line brown laying hens was conducted to assess the effects of dietary octacosanol supplementation on laying performance, egg quality and blood metabolites of laying hens. Hens were randomly allocated into 4 dietary groups of 8 cages each, which were fed basal diet supplemented with 0 (Control), 9 (OCT9), 18 (OCT18), and 27 (OCT27) mg/kg diet of octacosanol isolated from rice bran, respectively. The experiment was conducted in an environmental controlled house and hens were fed twice daily for ad libitum intake. Laying performance was determined over the 42-d period, and egg quality as well as blood metabolites were estimated on d 21 and d 42. Diets in OCT18 and OCT27 increased (p<0.05) laying rate, egg weight, egg mass, egg albumen height, Haugh unit and eggshell strength on d 42, but decreased (p<0.05) feed conversion rate and levels of total cholesterol, triglyceride and low density lipoprotein cholesterol in the serum as compared to those of Control. Feed intake, yolk color, yolk diameter, eggshell thickness and high density lipoprotein cholesterol were similar (p>0.05) among treatments. Results demonstrate that supplementing 18 to 27 mg/kg diet of rice bran octacosanol can improve laying rate and egg quality and reduce blood lipid of laying hens.

• Korean Journal of Heritage: History & Science
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• v.44 no.4
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• pp.112-129
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• 2011

This paper was written to understand, through the types and production techniques, how cooking vessels of Baekje Hanseong period had evolved, - the cooking vessels that were excavated from the historic sites of Baekje Hanseong Period such as Mongchontoseong and Pungnaptoseong of Seoul, the ancient tomb group of Seokchon-dong, and Misari historic site of Hanam. First, the results produced through the analysis of types of these cooking vessels are as followings: as for deep bowls, the maximum body diameter is found on the top of pottery, while as for an egg-shaped pottery, the maximum body diameter is found on the middle height of pottery. However, as for the rim diameter ratio to the neck diameter ratio of pottery, the said two typed potteries were shown to have smaller ones. In consideration of each historic site, as for deep bowls, the ancient tomb group of Seokchon-dong had potteries that had less volumes, were deeper, and had higher maximum body diameters. When it comes to an egg-shaped pottery, Pungnaptoseong had the potteries that were deeper than those of Misari historic site, and their potteries also had the maximum body diameter found on the middle height of pottery, and larger rim diameter ratio to the neck diameter of the pottery. The results produced though the analysis of the production techniques of these cooking vessels are as followings: in the case of deep bowls, as the width of a volume category gets larger, the pottery stamping with an anvil including patterns was more frequently used for pottery production. In this case, simultaneously braid patterns were frequently found on the outer sides of these potteries. In addition, it was found the basal walls of these potteries were thinnest in all typed potteries. This shows there occurred technique transitions according to the time flow. When it comes to an egg-shaped pottery as well, the pottery produced by using an anvil had the thinnest basal wall and its rim diameter ratio to its neck diameter ratio was smaller. Also around the mouth of this pottery, traces were found on its front, the traces formed by the strong rotating power. It is determined these two typed potteries were all produced by using an anvil to have thinner walls. Then, how these potteries were used? In the case of deep bowls, liquid food was put on a hearth or ground to be cooked whereas in the case of an egg-shaped pottery, the pottery was put on a puttumak(kitchen stove) mainly for boiling water. The deep bowls and egg-shaped potteries excavated from the center areas of Baekje Hanseong Period were not clearly determined about when their pastes or firing times were, but as for their production techniques, it was possible to check how they had developed. Moreover, it was determined that in the changing aspects of their production techniques, temporalite is also reflected.

• Korean Journal of Organic Agriculture
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• v.12 no.2
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• pp.219-230
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• 2004

In recent years, the consumption of livestock products were markedly decreased by awareness of world-widely occurred diseases including mad cow disease, Foot and mouth disease, Hog cholera, and Poultry Influenza virus. the consumers ara also wanting to have highly safe food such as organic animal products because of concerning about residual of antibiotics in animal products. However, disease control and impairment of productivity are the major problem in organic animal production. On these points of view, the present study was undertaken to investigate the effects of 1% or 2% of dietary probiotics fortified with various minerals on improvement of egg production and egg quality in old lay6r feeding low quality feed mainly composed of food waste, sesame meal, and rice bran. After 4 weeks of experimental feeding, the diameter of spreading of egg white was clearly decreased from 11.2cm of control eggs to 10.5m and 10.1m in 1% and 2% treatment group eggs, respectively. The color of egg yolk was 9.3 in control eggs but remarkably increased in treatment groups showing 10.1~10.2. Egg production was 75.8% in control layers but significantly increased to 79.8% of 1% treatment group and 82.9% of 2% treatment group layers. Egg weights (C : 66.3g, 1% : 73.2g, and 2% : 76.7g) and egg shell thickness (C : 0.33mm, 1% : 0.35mm and 2% : 0.36mm) were also increased by the addition of 1% or 2% of probiotics when compared to those of control group eggs. All together, it has been suggested that dietary addition of probiotics fortified with various minerals can improve the egg quality and egg production in layer's productivities by the recycling of organic waste resources such as food waste and agricultural by-products.

• Development and Reproduction
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• v.18 no.1
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• pp.25-31
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• 2014

This study was investigated spawning behavior, structure of egg masses and egg development in Aplysia kurodai inhabiting the coastal waters of Jeju Island, Korea. The mating and courtship behavior of A. kurodai occurred in the form of unilateral copulating with chain formation. In chain copulation, only the first animal acted as a female; the second and succeeding animals acted as males (sperm donors) to the animals in front and as females to the animals behind. The fertilized eggs were packaged in capsules that are embedded in jelly to form a cylindrical string called an egg masses. The number of capsule per cm of the egg masses was 55 to 60 capsules and each capsule within the egg masses held 15 to 25 eggs. After spawning, the egg masses were bright yellow or orange in color. This egg masses color not changed until embryos developed into trochophore stage. Thereafter, as embryo developed from trochophore stage to veliger stage the egg masses color became brownish. The fertilized eggs were spherical, with a diameter of approximately $80{\pm}1{\mu}m$ at spawning. At 5 to 6 days after spawning, the embryo developed into trochophore stage and began to rotate within the egg capsule. In the trochophore stage, the precursor of the velum, called the prototroch or prevelum, developed. At 10 days after spawning, the prevelum is transformed into the velum, and the trochophore developed into veliger stage. Between 10 to 15 days after spawning, the veligers broke out of the egg capsule, and hatched as free-swimming larvae.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.5
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• pp.516-523
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• 2011

To compare four populations of sea squirt Halocynthia roretzi adults, their egg quality and larval development were investigated in the hatchery. The populations were: south sea wild (SSW), south sea cultured (SSC), east sea wild (ESW) and Iwate Japan cultured (IJC). Egg quality and larval development were compared using 13 factors (fertilization rate and diameter, proximate composition, amino acid and fatty acid contents of eggs, hatching rate and various sizes of tadpole larvae) which were obtained from each population. Fertilized egg diameter, hatching rate and size of tadpole larvae were significantly different among the four populations (P<0.05). Eggs were produced with higher crude protein ($5.20{\pm}0.00%$ SSW, $4.71{\pm}0.01%$ ESW, $4.66{\pm}0.01%$ SSC and $3.96{\pm}0.01%$ IJC) and lipid ($1.22{\pm}0.01%$ ESW, $1.01{\pm}0.00%$ SSW, $0.77{\pm}0.01%$ SSC and $0.69{\pm}0.00%$ IJC,) contents from domestic wild populations than from Japanese or cultured populations. Also amino acid and fatty acid contents were different. The extent of similarity between domestic and Japanese populations (30.5% IJC:SSW, 34.3% IJC:SSC and 40.7% IJC:ESW) was relatively low but was very high between SSW and SSC (73.9%). These results may have been due to differences in the abundance of food types and environmental conditions in the four localities and consequent differences in the diets of the sea squirts.

• Journal of the korean society of oceanography
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• v.31 no.3
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• pp.144-149
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• 1996

I investigated the predation impact by the heterotrophic dinoflagellate Protoperidinium cf. divergens on copepod eggs in the presence of co-occurring phytoplankton prey (a preferred red-tide dinoflagellate Gonyaulax polyedra) and the selective feeding on mixtures of both prey. The ingestion rates of P. cf. divergens on Egg N (unidentified round copepod eggs with a smooth surface, about 80 in diameter) decreased by only 1.7-2 times when mean G. polyedra concentration increased by 57-115 times. In mixed prey experiments, P. cf. divergens preferred Egg N over G. polyedra even at 1.1 ${\mu}g$C $ml^{-1}$ or 470 cells $ml^{-1}$ of the latter. A strong preference of P. cf. divergens for Egg N over G. polyedra can be responsible for this relatively small effect. Protoperidinium may sometimes have a considerable predation impact on the populations of Egg N even during phytoplankton blooms or red-tide periods.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.250-251
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• 2003

Biochemical and biometric features of eggs of the Washington clam, Saxidomus purpuratus, are reported in this study. In addition, a polyclonal antibody against the purified clam egg was employed to quantitative assessment of eggs of the clams collected from Geoje Island, Korea in May 2002. Mean egg diameter was 70.81 $\pm$ 7.52 ${\mu}{\textrm}{m}$(histological preparation) or 88.56 $\pm$ 11.31 ${\mu}{\textrm}{m}$(purified oocytes), and individual egg weighed 95 ng in dry weigt. (omitted)

• Fisheries and Aquatic Sciences
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• v.13 no.2
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• pp.140-149
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• 2010

We determined the seasonal gonad maturation in Strongylocentrotus nudus sea urchins inhabiting an artificially enhanced seaweed forest along the Samchuk Coast of Korea from April 2006 to March 2007. A total of 30 sea urchins per month were collected from the study area, and gonadosomatic index (GSI), gonad index (GI), egg diameter, and RNA/DNA variation were measured for each specimen. GSI values of female and male urchins achieved maximums of 17.6 and 17.0, respectively, in June. Based on histological studies, maximum GI values occurred in July (4.6 for females and 4.8 for males). A mean ovarian egg diameter of $73.7\;\pm\;14.2\;{\mu}m$ was measured in August; during the main spawning period in September, mean egg diameter reached a maximum of $74.2\;\pm\;17.8\;{\mu}m$. The RNA/DNA ratio and RNA content for both males and females showed a distinct peak during the ripe stage in July, but another peak occurred in the spring season from March to April, when urchins deposit protein into the nutritive phagocytes of immature gonads prior to gametogenesis. The reproductive cycle of S. nudus is divided into five stages: early active (December-May), late active (March-July), ripe (July-September), spent and degenerative (August-November), and inactive (October-February). Our continuous removal of sea urchins from the study area did not influence the reproductive cycle, as populations quickly recovered, and achieved normal gonad development cycle in the site.

• Journal of Aquaculture
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• v.10 no.4
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• pp.463-472
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• 1997

Floating and hatching rates, size and survival activity index(SAI) of spawned eggs of red spotted grouper, Epinephelus akaara were studied to understand egg qualities during the spawning periods in 1992, 1993 and 1995. The fish spawned from mid-July to mid-August when temperature ranged 23~$28^\circC$. Floating, fertilization and hatching rates were higher in the eggs from early to middle than those from late during the spawning period. SAI ranged 1.8~9.6, and it was closely related to survival rate until mouth operning time (SMOT). Egg diameter decreased gradually with the time of spawning, while diameter of oil globule was constant during the spawning periods. Induced spawnings were carried out with one injection of HCG over 5, 000 IU/kg body weight. Floating, fertilization and hatching rates of the induced spawning eggs were higher than those of untreated ones. Thus, induced spawning method with HCG was recommended for collecting fertilized eggs in bulk. Optimal time for the collection of high quality eggs was supposed to be from early to middle during the spawning periods. Considering that egg qualities were vulnerable within the period, hatchability, incidence of malformed larvae, SMOT and SAI were factors to be considered together to get good quality of eggs.