• Animal cells and systems
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• 제3권4호
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• pp.375-383
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• 1999

Gonadal development, gametogenesis, reproductive cycle, and first sexual maturity of Reishia clavigera were investigated monthly from July 1998 to June 1999 through cytological and histological observations. R. clavigera had separate sexes, and was an internal fertilizer. The ma1e penis was located near the two tentacles. The ovary and testis were composed of a great number of oogenic lobules and spermatogenic tubules, respectively. The size of ripe oocyte ranged from 130 to 140 ${\mu}$m in diameter. The peripheral cytoplasm of the germinal vesicle of the ripe oocyte in many cases were surrounded by smaller yolk granules, while the eccentric cytoplasm was occupied with larger ones. The reproductive cycle of R. clavigera could be classified into five successive stages: early active, late active, ripe, spawning, and recovery. Spawning of females occurred from early July to August when the seawater reached above 24.8$^{\circ}C$. Spawning of males occurred from early June to August in the water above 22.8$^{\circ}C$. Minimum size for sexual maturity of both sexes was above 10.0 mm in shell height. Each egg capsule was a cylinder or spindle in shape, 4-6 mm in length and 1-2 mm in width. Colors of newly spawned egg capsules showed yellowish white or pale yellow, while those with veliger larvae showed pale black, and released larvae or dead egg capsules showed black violet. The fecundity in an egg capsule ranged from 70 to 91 eggs (mean＝80.28 eggs).

• 한국환경생태학회지
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• 제21권1호
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• pp.93-100
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• 2007

2004년 2월부터 2005년 6월까지 제주특별자치도 애월읍 신엄리에서 흑로의 번식과정을 조사하였다. 한배 산란수는 $3.24{\pm}0.75$개(N=17, 범위 $2{\sim}4$개)였으며, 알은 새벽이나 밤에 $1{\sim}3$일 간격으로 산란하였다. 알(N=39)의 크기는 장경 $46.73{\pm}l.91mm$, 단경 $34.06{\pm}0.83mm$, 무게 $27.67{\pm}3.12g$, 두께 $0.26{\pm}0.03mm$였다. 흑로의 둥지 보수나 짓기는 매년 2월부터 시작해서 늦게는 4월말까지, 산란기는3월초부터 늦게는 5월 초순까지였고, 부화기는4월 초순에서 5월 중순까지, 이소기는 5월 중순부터 7월말까지였다. 보충 산란은 1차 번식과정 중 포란과 육추에 실패한 $5{\sim}6$월에 바로 시도하는 것으로 추정된다. 포란 기간은 $28.17{\pm}4.12$일(N=6)이었으며, 알은 비동시성으로 부화되었다. 육추 기간은 $40.00{\pm}6.84$일(N=5)이었으며, 새끼의 부리, 날개, 부척, 체중의 성장속도는 부화가 빠른 개체일수록 빠른 경향을 보였다. 우리나라에서 번식하는 백로과 조류의 산란시기를 비교해보면, 흑로는 왜가리보다는 느렸으나, 해오라기, 쇠백로, 중대백로는 보다는 빨랐다.

• 한국가금학회지
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• 제35권3호
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• pp.275-281
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• 2008

산란계 사료에 lycopene을 첨가 급여하여 생산된 계란의 난황 중에 전이된 lycopene의 함량을 급여 기간별로 확인하고, lycopene 함유 계란의 난황색, 난중, 난각 강도, 난황고, 난백고, 난황 직경, 난황 계수와 Haugh Unit(호우 유닛) 등 계란의 각종 품질 특성과 이들 계란의 장기 보존에 따른 품질의 변화상을 조사하여 다음과 같은 결과를 얻었다. 1. 결과 lycopene 처리군의 계란 중 lycopene 농도는 난황액 1 gram 당 각각 약 1.56 ${\mu}g$과 1.57 ${\mu}g$ 이었으며, 대조군의 계란에는 lycopene의 함량이 없는 것으로 나타났다. 2. 사양 시험 2주경의 처리군의 난황 중 lycopene 함량 수준(23.4 ${\mu}g$)은 4주경의 수준(23.6 ${\mu}g$)과 유사하였다. 즉, 동일수준의 lycopene 첨가 사료를 지속적으로 급여하여도 난황 내 lycopene의 함량은 급여 기간의 경과에 따라 누적적으로 증가되지 않는 것으로 나타났다. 3. Lycopene 첨가군의 난황색 (P<0.01)은 대조군에 비하여 유의적으로 높은 수치를 보였다. 이외에도 처리군간에 통계적 유의성은 인정되지 않았으나 lycopene 첨가군의 난황고(P<0.08), 난황 직경(P<0.19), 난각 견실도(P<0.19), 호우 유닛(P<0.34), 난백고(P<0.33)도 대조군에 비하여 다소 높은 수치를 보였다. 각 처리군간에 난중의 차이는 없는 것으로 나타났다. 4. 계란을 실온에서 4주간 보관시킨 후, 이들의 품질을 측정한 결과, Lycopene 처리군의 난황색(EYC)은 대조군에 비하여 유의적으로 높았으나(P<0.01), 그 이외의 항목에서는 유의적 차이가 없었다. 저장 4주 후의 첨가군의 난백고와 난황고는 대조군 보다 크고 난황 직경(EYD)은 대조군보다 작게 나타났다. 이 현상은 첨가군의 호우유닛 수치를 대조군보다 크게 하는 데 영향을 미친 것으로 추정된다.

• 한국수산과학회지
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• 제49권3호
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• pp.404-409
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• 2016

We investigated the maturation and spawning of Sebastes thompsoni in the coastal waters off Ulleungdo, based on samples collected by gill net from March 2013 to February 2014. We analyzed monthly changes in maturity stage, gonadosomatic index (GSI), egg diameter, fecundity, and total length (TL) at 50% group maturity. The average TLs of female and male S. thompsoni were 22.6 cm and 22.5 cm, respectively. The main parturition period of females was during March and April. The GSI of females began to increase in January, and reached a maximum in March. The GSI of male reached a maximum between January and February. The spawning period of males was shorter than that of females. The egg diameter during gestation stage was 1.4±2.1 mm. The TL of females at 50% group maturity was 22.3 cm.

• 한국양식학회지
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• 제21권4호
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• pp.234-238
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• 2008

고등어 Scomber japonicus의 종묘생산 및 양식가능성을 조사하기위하여 난발생에 따른 수온과 염분의 영향을 조사하였다. 수정란의 난경은 $0.91{\sim}1.33\;mm$였으며, 1개의 유구를 갖고 있는 구형의 분리부성란이었다. 수정에서 부화에 이르기까지 평균 소요시간은 $16^{\circ}C$일 때 약 70시간, $20^{\circ}C$일 때 48시간, $24^{\circ}C$일 때 42시간, $28^{\circ}C$일 때 34시간으로 고수온일수록 빠른 경향이었다. 부화율은 자연해수 조건인 $20{\sim}24^{\circ}C$와 $33{\sim}35\;psu$ 범위에서 가장 양호하였다. 난발생의 각 단계에 이르기까지 수온(T: $^{\circ}C$)에 따른 발생속도(t: hour)는 수온이 높을수록 빨랐으며, 난발생이 진행되지 않는 생물학적 영도는 평균 $6.9^{\circ}C$로 추정되었다.

• Archives of Pharmacal Research
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• 제18권2호
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• pp.84-89
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• 1995

The complexation and physical characteristics of egg phosphatidylcholine (PC) liposome containing amphotericin B(AmB) were investigated through circular dichrosim(CD) spectra, the size distribution, the turbidity change, and the calcein release. CD spectra of AmB-containing egg PC mxture exhibited a positive peak around 330 nm indicative of complexation of AmB and four negative peaks. The positive peak increased up to $2.2{\;}millidegree/{\mu}g$ AmB as AmB contents increased up to 12% (w/w), suggesting that AmB-phospholipid complexation was promoted by the antibiotics. The effective diameter of liposomesa by dynamic light scattering decreased from 450 nm to 220 nm as the amount of AmB in liposomes increased from o to 30% (w/w). The complexation may be responsible for the reduction in size. On the other hand, at around 1 mN deoxycholate (DOC), the reltive turbidities of 5 and 10% (w/w) AmB-containing liposome suspension were less than 1 probably due to the soblubilization of the complex, while those of pure PC liposome suspension were larger than 1 at the same concentration. Deoxycholate-induced release of liposomes, indicating the intercalation of the drug into the bilayers. Therefore, it is concluded that in AmB/eggPC/water system, AmB-phospholipid complexcoexists with AmB-containing liposomes.

• The Korean Journal of Ecology
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• 제1권2호
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• pp.44-48
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• 1977

The spawning behavior and developmental pattern of the Korean eleotrid fish (Odontobutis obscurus) was investigated in one of the tributary of Han River. The spawining of this species begins on April and continues up to August, whereas, the spawning. of same species were between the end of June and the middle of July in Kyushu, Japan. August The spawning places were the margin of river, its the bottom composed of sand and pebble (Table 5). The velocity of water in the spawning places was 0-40cm/sec, and the depth of waters was 10-40cm. The egg was spawned on underside of stone in the spawning places with one or two folds and ellipsoid in shape, 3.4mm in long diameter and 2.0mm in short diameter. The yolk is 1.2mm in diameter and yellow in color. For hatching of the egg, it takes one month in, $16^{circ}C~19^{\circ}C$ water, in Japan, whereas it takes only 14 days in $20^{circ}C~30^{\circ}C$ wate rin the study area. The growth rate of larva and juvenile fish were as follows: new hatched larva is 45mm in length; after 5 days it became 5.0 to 5.5mm in length and 1.2 to 1.5mm in height after 20 days. it became 11.0mm in length and 2.3mm in length. The mean size of the mature female is 110mm in total length and larger 10mm than that of the same fish found in Japan.

• Applied Microscopy
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• 제44권2호
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• pp.47-52
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• 2014

Fine structural characteristics of eggs (nits) found on the scalp hairs of Korean children were observed with scanning electron microscopy. An egg is structurally composed of four parts: the cementum, nit body, operculum, and aerophyle. The total length of an egg is about 1.5 mm. The glue secreted from the female louse completely surrounds the 1 mm hair shaft and forms the cementum. The thickness of the cementum at the end of the nit body was found to be more than 5 times the thickness at the end toward the scalp. The nit body is shaped like a goblet with a very smooth surface. The operculum and aerophyles are located at the apiculus area. In the circular operculum, there are 10 aerophyles concentrated on the side of the hair shaft surface that are shaped like a dome. Three aerophyles in the center are surrounded by 7 aerophyles. Each aerophyle is dome shaped with a diameter of $65{\mu}m$ and a respiratory pathway with a $15{\sim}25{\mu}m$ opening at the center. On the cut surface where the operculum is separated as the egg hatches, long grooves about $1{\mu}m$ thick are uniformly formed transversely. These long grooves facilitate the separation of the operculum through body expansion at the time of hatching.

• 한국양식학회지
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• 제10권1호
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• pp.17-24
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• 1997

한국산 갯지렁이류 중에서 산업적으로 가장 중요한 청충의 양식기법 개발에 관한 기초자료를 얻기 위하여, 실내에서 인공사육한 청충의 생식과 발생에 관하여 조사한 결과는 다음과 같다. 1. 0.4~2.4 g의 청충을 자연수온 및 $20.0\pm1.0^\{\circ}C$와 $25.0\pm1$의 가온구에서 사육한 결과, 생식형의 체중(Wt)과 산란량(NS)과의 관계는 NS=48635.5897Wt 상(1.3044) (r=0.8572)의 식으로 나타났다. 2. Atokous segment 는 암컷이 23~28(평균24.8$\pm1$), 수컷은 22~29(평균24.6$\pm2$)개로 같았고, 체색에 의한 암수의 차이는 없었다. 3. 수정란의 난경은 $220\mu m$으로, 수정 21.0~$23.0^{\circ}C$에서 수정후 56시간 만에 부화하였다.

• Journal of Ginseng Research
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• 제16권2호
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• pp.146-150
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• 1992

Life history, ginseng damage, and chemical control of the snail Acusta despecta sieboldiana Pfeiffer were investigated in the field and laboratory conditions from 1987 to 1990. Eggs of the snail were whitish globular and 1.,93${\pm}$ 0.09 mm in diameter which were deposited as egg mass composed of 28.4${\pm}$ 15.4 eggs. Egg period was 11.8${\pm}$ 1.6 days under the laboratory condition. Most eggs were laid during mid July in the field. The snail had a life cycle of a year and hibernated from November to April. Significant ginseng damages by the snail (over 10% to the total number of plants) were observed only in the three to five year old ginseng fields with rice straw mulching. Based on the dates that the first ginseng damages were observed and on the questionary examination, ginseng damages seemed to occur from May to July. Metaldehyde (6%) bait showed reliable control effects on the snail.