• KOREAN POULTRY JOURNAL
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• v.29 no.8 s.334
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• pp.78-82
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• 1997

• KOREAN POULTRY JOURNAL
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• v.30 no.3 s.341
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• pp.81-85
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• 1998

• Korean Journal of Poultry Science
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• v.20 no.4
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• pp.197-201
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• 1993

The objective of this study was to investigate the effects of hatch and sex on the body weight and shank length of growing pheasant. Least squares means of body weight at the age of 0, 4, 8, 12, 16 and 20 wks were 17.9, 96.0, 296.4, 563.4, 709.0 and 757.4 g for female, and 18.3, 104.4, 349.1, 728.5, 1001.4 and 1101.6 g for male, respectively. The hatch effect on body weight was significant at the age of 4, 8, 12 and 16 wks (P＜0.05), but the effects on shank length were significant at the age of birth and 8 wks only. There was no significant hatch effect on both the body weight and shank length at the age of 20 wks(P＞0.05). Least squares mean differences between female and male were significant(P＜0.01) over all wks of age except at hatch.

• KOREAN POULTRY JOURNAL
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• v.52 no.9
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• pp.142-144
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• 2020

혹서기를 지나 환절기에 들어가면서 환절기 부화율 향상을 위한 종계 사양 관리에서 가장 큰 난점은 일교차에 따른 환기 관리와 여름을 지나면서 지쳐있던 수탉계군의 컨디션을 얼마나 잘 향상·유지하느냐에 있다. 이런한 난점을 해결하기 위해서는 단열과 적정 환기 등으로 계사 내의 온도 차를 줄이고 계사 내 환경을 쾌적하게 유지하며, 양질의 적절한 사료 관리와 체계화되고 주기적인 수탉 관리로 환절기 종계의 부화율 향상에 도움이 되었으면 한다.

• Journal of Aquaculture
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• v.12 no.1
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• pp.25-30
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• 1999

This study was carried out to produce the seedling of the larvae and juveniles of pale chup, Zacco platypus (Cyprinidae) in terms of artificial hatching, feeding behavior and growth rates. The total lengths of the newly hatched larvae were 7.6~8.2mm (mean: 7.97mm). The hatched larvae rose to the surface 3 days after hatching. The larvae were fed Daphnia, rotifer, Artemia and powdered feed. Hatching experiments were conducted in jar incubators under the different water temperature conditions, $20~32^{\circ}C$. The highest hatching rate was at $26^{\circ}C$ after 47 hours. Jar incubators was the highest hatching rate (89%), and cage and Californian incubators were useful and relatively high hatching rates (>89%). The size of the larvae 50 days after hatching were 30.0mm (25.6~32.0mm). As the water temperatures was increased, the growth rate of the larvae was also increased. Especially, the growth rates were favorable over $26^{\circ}C$, but survival was the worst at $32^{\circ}C$. This species was quick to accept assorted feed after hatching. The assorted feeds for flounder and rockfish better than that of carp in reference to growth rate.

• The Korean Journal of Ecology
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• v.26 no.1
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• pp.1-4
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• 2003

In diurnal activity of the black-crowned night herons on breeding season, activity budget was that male were standing(29.5%), preening(21.5%), comfort(10.9%), and female were resting(26.3%), repairing (18.4%), preening(15.3%) in sequence. Activity budget was high significant between male and female(p<0.01). In case of activity-time budget sequence, male was standing(38.7%), locomotion(33.8%), preening(11.5%), and female was resting(55.4%), standing(18.4%), preening(9.4%). Therefore, activity-time budget was significantly different in male and female(p<0.01).

• Development and Reproduction
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• v.5 no.1
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• pp.17-21
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• 2001

This study was conducted to investigate the expression pattern of Trypsin-like enzyme and the effect of a trypsin inhibitor(benzimidine) on hatching process during in-vitro culture of mouse preimplantation embryos. The Trypsin-like enzyme was identified by rhodamine-conjugated Trypsin substrate probe. The expression of trypsin-like enzyme was firstly detected at the late morula stage, and the enzyme was uniformly localized in the trophectoderm of late blastocysts. Especially, intense fluorescence was observed in the blebbing area of hatching blastocysts. Bisbenzamidine, contained in culture media, did not alter embryonic development from 4-cell stage to the expanded blastocyst but decrease the hatching rate in ImM concentration (15.8% vs 89.7%, p<0.02). In the treatment of bisbenzimidine (5mM) for 12 hours according to the embryonic stage of mouse, the hatching rate of control (83.0%) and treatment in late blastocysts (8.7%) were significantly (p<0.01) different. From these results, we suggested that the hatching enzyme having trypsin-like activity was localized from the late morula stage, and the hatching process by this enzyme was activated in the late blastocyst stage of mouse embryos.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2004.11a
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• pp.105-106
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• 2004

본 연구는 초등학교 실과교과 '동물 기르기 단원'의 병아리 부화수업을 위한 교수-학습자료 개발을 위해서 실시되었다. 본 연구의 진행을 위해서 수정란, 부화기 및 육추기 등의 준비와 동시에 부화수업을 위한 사전 지식이 탐구되었다. 뿐만 아니라 본 수업을 위한 학습지도안이 총 3차시의 분량으로 만들어졌다. 본 수업을 통한 교육적 효과는 아동들로 하여금 직접 경험하고 실습하는 과정에서 배우게 되는 외재적 효과는 물론이거니와 무엇보다도 생명의 소중함을 깨닫게 하는 내재적 가치도 함께 기대할 수 있을 것이다.

• Journal of Aquaculture
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• v.11 no.4
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• pp.529-546
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• 1998

Gonadal part that developed by indifferentiation period for 6 months after hatching is made as gonad and fat body. These gonad are thin semi-transparant and undistinguished germ cell. Germinal epithelium is distinguished by development of gonad epithelial tissue from 7 months after hatching. Sex differentiation is begun by oogonia develoment at 8 months after hatching. Primary oocytes grow over germinal epithelium of gonadal cavity, at 9 months after hatching, gonadal cavity become ovarian cavity as they increasing. As soon as oocytes at 13 months after hatching are filled with the whole part of gonad, degeneration of oocyte is begun. And then, gonad has cavity tissue, a small number of oocyte are located in gonadal cavity. At 15 months after hatching, new primary oocyte develop and cavity of ovarian tissue in the central of ovarian cavity. Spermatogonia multiplicate and cavity tissue consist of testicular tissue. These gonad become hermaphrodite and then ditermine the sex of female and male. These results show the red sea bream is juvenile hermaphrodite and undif-ferentiated gonochoristic teleost. Male and female differentiation type of gonad is divided in undifferentiation stage, oogonia-like stage, ovary-like stage, ovary development stage, hermaphroditic testis stage, hermaphroditic ovary stage, and testis development stage. Undifferentiation stage is continued total lenth 18cm at 13 months after hatching. ovary-like stage is continued total length 11~18cm at 13 months after hatching. Ovary-like stage is continued total length 14~26cm at 10~14 months after hatching. Ovary development stage begins from total length 20cm, 14 months after hatching. At 20 months after hatching, 44 percent of total sampled individuals had ovary. Hermaphroditic ovary stage first begins total length 19~20 cm at 15 months after hatching, but it is not observed total length 28~29cm at 20months after hatching. Hermaphroditic testis stage first begins total length 21~22cm at 20months after hatching and is continued for 20months. Testis development stage first begins total length 20~21cm at 20 months after hatching, and is occupied 33 percent total length 28~29cm at 20 months. The beginning of sex differentiation more than 50 percent is from total length 16cm at 11 months after hatching. Sex determination begins total length 20cm, 14months after hatching in female and total length 20cm, 15 months after hatching in male. Sex determination more than 50 percent begins total length 23cm,, 17 months after hatching. Undifferentiated gonadal part of red sea bream consist gonad and fat body. As differentiation is going on and gonad is growing, fat body shrinks. This appearence is showed the same tendency in 3-year old red sea bream. 1.9mm larvae after hatching grow about 19mm larvae for 47 days. The relationship between the total length and body weight of larvae and juveniles in $BW=4.45{\times}10^{-6}TL^{3.4718}$ r=0.9820. Fishes in cage culture grow to maximum total length 28.4cm. The relationship between the total length and body weight of these fishes is $BW=2.36{\times}10^{-2}TL^{2.9180}$, r=0.9971. Undifferentiated gonadal part of red sea bream consist gonad and fat body. As differentiation is going on and gonad is growing, fat body shrinks.

• Journal of Aquaculture
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• v.11 no.3
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• pp.337-344
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• 1998

This paper documented mophological changes of embryonic development and first zoea larvae of snow crab, Chinoecetes opilio. Female crabs were sampled by the Danish seine fishery at the depth about 200m in Sep. 1997 in the eastern coast of Korea. Female with newly berried eggs was reared at the water temperature of 5$^{\circ}C$ till the time of hatching. The results obtained are as follwos. Embryonic development : According to morphogenesis of fertilized eggs, the developemental process of the embryo was classified into the following seven stages : First stage (cleavage and blastula stage, 24 days) Second stage (gastrula stage, 72 days) Third stage (nauplius stage, 22 days) Fourth stage (metanauplius stage, 57days) Fifth stage (stage of a pigmentary deposit in the compound eye, 30 days) sixth stage (chromatophore appearance stage in maxillipede, 56 days) Seventh stage (hatching stage, 36 days) Larvae hatched as prezoeas and they molted to first zoea in about an hour. The first zoea is 4.6 to 5.1mm in length, 3.2~3.6mm in width. The abdomen consists of five segments and a bifurcate telson.