• Fisheries and Aquatic Sciences
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• 제14권4호
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• pp.429-433
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• 2011

Eggs of Korean rose bitterling Rhodeus uyekii were collected and fertilized to observe temperature-related cleavage rates and mitotic intervals (${\tau}_0$). As the water temperature was increased, the slope of first cleavage frequency with elapsed time after fertilization increased, and approximately 30% of fertilized eggs reached first cleavage frequency at every 15 min. At higher temperatures, eggs developed faster and underwent further identical developmental processes. There were strong, negative correlations between ${\tau}_0$ and water temperatures at all temperatures studied (Y = -1.225X + 70.05, $r^2=0.988$, where Y is ${\tau}_0$ and X is temperature).

• 한국어병학회지
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• 제14권1호
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• pp.11-15
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• 2001

White Spot Baculovirus(WSBV) 미감염 새우 건강 종묘를 생산하기 위하여 난의 요오드 소독을 실시하였다. 유효 요오드농도 20,50,100,200 ppm에서 각 시험구의 대하(Penaeus chinensis) 수정난을 각각 30,60초 처리한 결과 각 농도의 30초 처리구에서는 50%이상의 상대부화율을 보였고, 60초 처리구에서는 20ppm 처리구에서만 약 50% 상대 부화율을 보인 반면 50 ppm이상에서는 부화율이 거의 없었다. 보리새우(Penaeus japoni cus)에서도 비슷한 결과를 보였다. 대하의 경우 세란만 실시한 대조구의 부화율은 33.3%이었지만, 보리새우는 55.2%로 상대적으로 높았다. 부화후 생존율을 보면 수정난의 소독으로 부화율은 낮아지지만 수정란 소독후 부화된 유생은 초기생육에는 문제점이 없었다. WSBV 미감염 건강종묘를 생산하기 위해서는 수정난을 세척하고 저농도의 요오드를 짧은 시간에 소독해야 한다.

• 한국패류학회지
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• 제30권4호
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• pp.303-309
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• 2014

코끼리조개의 대량 인공종묘생산을 추진하기 위한 기초연구로서 수정란, 유생 및 치패의 발달을 조사하였다. 생식체는 잘 성숙한 어미에서 추출하여 희석 정자 용액으로 수정하였으며, 발생유생은 수온 $19{\pm}1^{\circ}C$로 유지하였다. 수정란의 난경은 평균 $81.6{\mu}m$ 이었으며, 수정 후 14시간 만에 담륜자 유생이 되어 부상하고, 27시간 만에 D상 유생 (각장 $116{\mu}m$)으로 발달하고, 20일 후에는 각장 $311.2{\mu}m$로 성장하여 바닥에 안착하였다. $18.5-21.5^{\circ}C$에서 정상적으로 부화 및 유생사육이 가능하였으며, 채묘기질은 모래가 우수하였으나 캐시미론도 양호하였다. 부유유생이 착저한 후 108일간 사육한 결과 각장 13 mm, 전중량 0.4 g으로 성장하였고 일간성장률은 각장 $117.5{\mu}m$ 이었으며, 자연해수로 연중 실내육성이 가능하였다.

• Applied Microscopy
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• 제52권
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• pp.6.1-6.5
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• 2022

We examined the morphology of the fertilized egg and the fine structure of fertilized egg envelopes of Poropanchax normani belonging to the family Poeciliidae, also known as Norman's lampeye using light and electron microscopes. The fertilized eggs with narrow perivitelline space were found to be spherical and demersal, additionally containing small oil droplets in the vitelline membrane. Further, a bundle of adhesive filaments was observed to be present on one side of the fertilized egg. These filaments possessed remarkably high elasticity and were approximately 1-3mm in length. The size of the fertilized egg was determined to be about 1.49 ± 0.07mm (n=30). The outer surface appeared smooth, and adhesive filaments originating at different location of the surface of the envelope were found to be distributed around the egg envelope and were joined together to form a single long bundle in scanning electron microscopic observation. A peak-like structure formed of several straight wrinkles was observed around the micropyle. However, the complete structure of the micropyle could not be studied due to the depth at which it was located. Additionally, the total thickness of the egg envelope was ascertained to be approximately12.5-14.5㎛. The egg envelope consisted of two distinct layers, an outer electron dense layer and an inner lamellar layer, further consisting of 10 sublayers of varying thicknesses. Collectively, it was observed that the morphological characteristics of the fertilized egg, fine structures surrounding the micropyle, outer surface, adhesive structure consisting adhesive filaments, and sections of fertilized egg envelope displayed species specificity.

• 한국수산과학회지
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• 제53권4호
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• pp.506-514
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• 2020

We investigated seed management and feeding regime of larval red spotted grouper Epinephelus akaara using live food organisms. Fertilized eggs were produced in March 2020 by manipulating photoperiod and water temperature. Broodstock (F0) produced approximately 0.30×10⁶ eggs, of which 0.25×10⁶ were fertilized; first-generation broodstock (F1) produced 2.00×10⁶ eggs, of which 1.90×10⁶ were fertilized. Larvae were reared at temperatures of 21.0-24.5℃. The feeding regime consisted of rotifers Artemia, and commercial pellet feed. From 5-8 days after hatching (dah), rotifers collected from high-density incubation tanks were fed to grouper larvae at a density of 10-20 individuals/mL. From 9-30 dah, rotifers collected from low-density incubation tanks were fed to larvae at a density of 10-20 individuals/mL. Newly hatched Artemia were provided from 20-24 dah and enriched Artemia from 25-50 dah. Commercial pellet feed was given starting at 13 dah. The average mouth size in hatchlings was 263.4±3.7 ㎛ at 5 dah, 406.7±21.0 ㎛ at 11 dah, and 856.9±136.6 ㎛ at 21 dah. At 1 dah, larvae had a mean total length of 1.95±0.06 mm. At 66 dah, the mean TL was 4.0 cm. The final number of surviving red spotted grouper larvae was 218,380 fishes.

• Environmental Analysis Health and Toxicology
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• 제20권1호
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• pp.57-65
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• 2005

Effects of five polycyclic aromatic hydrocarbon (PAHs) constituents (naphthalene, fluorine, fluoranthene, benzo(a)pyrene, pyrene) on fertilization and early development of sea urchin egg, sperm and fertilized egg were investigated. The eggs, sperm and fertilized eggs were exposed to several concentrations of PAHs (1, 10, 100, 1000 and 10000㎍/L). The rate of fertilization and hatching decreased when the eggs and sperm were exposed to aqueous solution of PAHs. Also, Exposure of fertilized eggs with each PAHs did decrease survival and hatching rate. Concentration-dependent toxic effects on the rate of fertilization, hatching, survival and abnormality in A. crassispina were observed following exposure to PAHs (1, 10, 100, 1000 and 10000㎍/L). These data show that PAHs exposure decreased in fertilization success of sea urchin egg and sperm and producted abnormal embryo. It is plausible to suggest that PAHs had the potential to significantly reduce coastal recruitment of sea urchin.

• 한국어류학회지
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• 제31권1호
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• pp.23-29
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• 2019

이번 연구에서 바리과 어종의 새로운 교잡종을 생산하기 위한 연구의 일환으로 능성어 (Hyporthodus septemfasciatus) ♀${\times}$대왕바리 (Epinephelus lanceolatus) ♂ (CGGG)의 발생 양상, 부화율, 기형 발생률 그리고 부화 소요시간을 조사하고, 교잡종의 모계어종의 순종 (능성어 ♀${\times}$♂, CG)과 비교하였다. CGGG와 CG 수정란은 자외선 살균 해수가 채워진 5-L 용량의 비이커 9개에 3,000~5,000개/비이커의 밀도로 수용되었으며, 발생 기간 중 수온은 $23.5{\sim}24.8^{\circ}C$ 그리고 염분은 32.1~32.8 ppt 였다. CGGG의 수정률과 부화율은 각각 $69.4{\pm}1.5%$와 $59.0{\pm}5.1%$로서 CG에 비해 유의하게 낮았다 (p<0.05). CGGG는 비균등 난할, 배체 체형 기형 그리고 부화자어의 척추 기형이 높게 출현한 것을 제외하고, CG와 동일한 난발생 양상을 보였다. CGGG의 부화까지 소요 시간은 CG에 비해 약 2시간 느렸다(p<0.05). 이상의 결과에서 CGGG는 수정률, 부화율 그리고 기형률 등 발생능력이 CG에 비해 낮았지만 부화자어의 대량생산이 가능할 것으로 판단된다.

• Ocean and Polar Research
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• 제42권4호
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• pp.303-311
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• 2020

In this study, the embryonic development and hatchability of eggs fertilized by the reciprocal hybrids of kelp grouper (Epinephelus bruneus) and red-spotted grouper (E. akaara) were evaluated with the goal of establishing a novel hybrid with enhanced growth and viability during the farming period in the temperate waters of Korea. The fertilization rates were lower for hybrids than for maternal purebreds and were significantly higher in the red-spotted grouper ♀ × kelp grouper ♂ hybrid (RGKG, 89.61 ± 1.58%) than in the kelp grouper ♀ × red-spotted grouper ♂ hybrid (KGRG, 74.82 ± 4.23%, p < 0.05). Unlike the fertilization rates, the hatching rates of fertilized eggs were similar between hybrids and maternal purebreds and did not differ significantly between KGRG and RGKG (72.74 ± 3.60% vs. 75.23 ± 2.20%, respectively, p > 0.05). The embryonic development of the hybrids was similar to that of maternal purebreds; however, irregular cleavage and asymmetric blastoderm were noticeable in the developing eggs of KGRG hybrids. The deformity rates of newly hatched larvae were higher in hybrids than in maternal purebreds and were significantly higher in KGRG than in RGKG (17.47 ± 1.28% vs. 7.11 ± 0.54%, respectively, p < 0.05). These results demonstrate the potential to produce viable larvae from these two hybrids. Although the production efficiency of KGRG was lower than that of RGKG, the fertilization, hatching, and deformity rates make both hybrids useful for further comparative studies regarding economic aspects.

• Ocean and Polar Research
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• 제40권3호
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• pp.161-167
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• 2018

We examined the effect of salinity and water temperature on hatching and survival rates of fertilized eggs of hybrid grouper (Epinephelus fuscoguttatus ♀ ${\times}$ E. lanceolatus ♂) at different developmental stages, determining optimal conditions for their long-distance transportation. Deformities and hatching rates of fertilized grouper eggs were observed at salinities of 24, 27, 30, 33, 36, and 39 psu. The optimal salinity was determined to be 36 psu, with a survival rate of $70.0{\pm}2.0%$. Transportation experiments at 36 psu were conducted at water temperatures of 21, 24, 27, and $30^{\circ}C$, different developmental stages such as morula, 5-myomere, and tail beating for hatching and survival rates. The optimal water temperature and developmental stage for transporatation were $30^{\circ}C$ and tail beating stage and those hatching rates were $50.6{\pm}1.9%$ and $86.3{\pm}1.3%$, respectively. At $21^{\circ}C$, the survival rate by transportation water temperature was highest ($73.1{\pm}10.6%$), but the hatching rate ($17.1{\pm}3.1%$) was lowest. Therefore, the hybrid grouper fertilized eggs (E. fuscoguttatus ♀ ${\times}$ E. lanceolatus ♂) can be most efficiently produced under long-distance transportation conditions during the tail beating stage and at a water temperature of $30^{\circ}C$.

• 한국수산과학회지
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• 제52권5호
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• pp.534-538
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• 2019

The distribution and characteristics of spawning beds of the Pacific herring Clupea pallasii, were observed by scuba diving in Jinhae Bay, Korea, with a focus on marine vegetation as adhesive substrates and egg density during the spawning season. In 2017, the fertilized eggs of C. pallasii were mainly found attached to the leaves of algae species Carpopeltis cornea, Gracilaria textorii, and Acrosrium polyneurum at the rocky shore in Wonpo-dong and Jeodo. The mean density of fertilized eggs in C. pallasii spawning beds was $153,776eggs/m^2$ off Wonpo-dong and $856,430eggs/m^2$ off Jeodo, giving an estimated total of $5.345{\times}10^9$ eggs in Wonpo-dong and $3.3074{\times}10^{10}$ eggs in Jeodo. We examined spawning beds with an area of $38,619m^2$ off Wonpo-dong and $34,760m^2$ off Jeodo. The choice of spawning bed may be affected by the composition of marine vegetation, such as the algal diversity of rocky shore environments, which could affect adhesive substrates and egg density during the spawning season. The results of the present study suggest that the spawning season of C. pallasii in Jinhae Bay is in January to mid-February.