• Journal of Microbiology and Biotechnology
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• 제17권3호
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• pp.511-515
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• 2007

White-spot syndrome virus (WSSV) is a devastating, infectious virus affecting shrimp. Although sensitive techniques involving PCR have been developed to assist farmers in screening shrimp (brood stock) for WSSV prior to stocking ponds, such practices have not yet been applied in Korea. Despite the rationality of implementing screening, there has been some doubt as to whether the stocking of WSSV-PCR-negative fly epidemiologically decreases white-spot disease outbreaks. Here, we report a retrospective analysis of data from shrimp farms in the western coast of Korea where WSSV-PCR-negative brood stocks were used to stock rearing ponds. A total of 366 shrimp from Heuksan Island were sampled for WSSV with PCR. Of the tested shrimp, 7.2% (28 brood stocks) were identified as WSSV positive; only WSSV-PCR-negative shrimp were used for brood stocks. Total unit production (final shrimp production/ the area of the ponds) was higher, at 1.96, in ponds where WSSV-PCR-negative shrimp were used, as compared with 1.02 in other ponds in Korea in 2004. This retrospective analysis of WSSV in Korea may be useful to the shrimp aquaculture industry, suggesting a testable hypothesis that may contribute to the eventual control of WSSV outbreaks.

• Fisheries and Aquatic Sciences
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• 제11권2호
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• pp.82-87
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• 2008

Marine fisheries are important natural resources and must be maintained, especially fish species that are important sources of food. Despite the increase in stocking programs to maintain fisheries with artificially raised fish, the genetic impact stocking has on the wild fry population has not been addressed. Genetic variation in rock bream, Oplegnathus fasciatus, within and between wild-caught parents and the $F_1$ generation produced by them in 1 day was assayed using nine highly variable micro satellite markers. The nine micro satellite loci used in this study displayed diverse polymorphisms, and in total, 98 different alleles were observed over all loci. Differences in genetic variability of the $F_1$ offspring compared to their wild-caught parents (brood stock) were observed in terms of allele frequency, gene diversity, and heterozygosity. Although the $F_1$ generation of rock bream was missing 16% of the micro satellite alleles, no significant reduction was found in mean heterozygosity of the $F_1$ population compared to the brood stock. Eight of nine loci showed significant Hardy-Weinberg equilibrium (HWE) deviations in the $F_1$ population, while the brood stock deviated from HWE at three micro satellite loci (KOF85, KOF360 and KOF374). These deviations showed mostly a deficit of heterozygotes. Our results provide evidence for genetic differences in the $F_1$ hatchery offspring compared to their wild-caught parents and reinforce the need for a series of consecutive egg collections to avoid the loss of genetic variability. This also further underscores the importance of monitoring genetic variability of hatchery populations for the conservation of natural rock bream resources.

• 한국어병학회지
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• 제13권1호
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• pp.53-59
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• 2000

우리나라 연안의 9곳의 지역에 위치한 넙치종묘생산장의 성숙 친어 및 친어용 자연채집어를 대상으로 각각의 생식소를 채집하여 체내 MABV 감염상황을 PCR법을 이용하여 검색한 결과 검사어의 34%가 MABV 감염 양성반응을 나타내었다. PCR 반응양성 어류의 샘플로부터 CHSE-214 세포주를 이용한 바이러스의 배양을 행한 결과, 친어 체내 생식소에 있어 바이러스 감염가가 $10^{2.30}$에서 $10^{4.30}$ $TCID_{50}$/g(ml)의 titer를 보여, 정상적인 친어로 보이는 개체내의 바이러스 잠복감염이 인정되었다. 각각의 다른 어체로부티 분리되어진 바이러스는 중화반응에 따른 검토결과 동일종의 MABV임을 확인할 수 있었다. 종묘생산용으로 관리중인 넙치 친어로 부터 MABV의 잠복감염 확인으로 친어를 매개로한 감염의 가능성이 확인되어졌다.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2001년도 추계 수산관련학회 공동학술대회발표요지집
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• pp.281-282
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• 2001

미세조류의 배양은 천해양식 생물의 종묘생산 시 먹이생물로서 가장 중요한 요인이 된다. 종묘생산은 친어(brood stock)의 관리와 산란된 난에서 부화된 자ㆍ치어의 사육으로 구분할수 있다. 이때 자ㆍ치어 사육의 근본적인 과제는 적합한 먹이생물의 확보이며 이는 곧 미세조류의 대량배양이라 할 수 있다. 먹이생물이 확보되지 못한 생태에서는 자ㆍ치어 사육은 불가능하므로 천해양식산업에서 미세조류의 배양은 가장 중요한 근본과제이다. (중략)

• 한국양식학회:학술대회논문집
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• 한국양식학회 2003년도 추계학술발표대회 논문요약집
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• pp.145-145
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• 2003

To evaluate the effect of PAHs on fertilization and larval development of the Pacific oyster, Crassostrea gigas via in vivo exposure for 30 days. Conditioned C. gigas adult brood stock was taken from oyster farm in May 2003 and raised in flow through tank at 20-22$^{\circ}C$ with feeding equivalently mixed marine microalgae: Chaetoceros simplex, C. gracilis, Isochrysis galbana and Tetrasemis tetrathele. The oysters were exposed to PAHs cocktail at 200ppb (10 species) until they are fully riped with an untreated group. Motility of sperm, Fertilization and The percent of D-shaped larvae was measured under microscope (Olympus BX-50). Fertilization capability using dry sperm and eggs from both non- and PAHs treated brood stocks was significantly reduced at the treated group (P<0.01). In addition to the origin effect, it was obvious that fertilization of eggs from both group were adversely suppressed in consistent with PAHs level (P<0.01). The percent of D-shaped larvae in treated group was significantly reduced comparing to non-treated. The percent was adversely correlated with PAHs level, which was more significantly reduced in treated group. Therefore, it was obvious that PAHs exposure on the Pacific oyster has adverse affects on the sperm as well as larvae in both maternal and acute source.

• 한국수산과학회지
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• 제30권2호
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• pp.211-215
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• 1997

감성돔, Acanthopagrus schlegeli 정자의 단기보존을 위한 기초자료를 얻기 위하여, 순환여과사육 시스템에서 사육한 전장 $25.9{\pm}1.7cm$, 체중 $292.8{\pm}53.7g$의 성숙한 어미로부터 정액을 채집하여 정자의 액상보존 효과를 조사하였다. 희석액별 단기 액상보존 실험에서 혈청을 사용하였을 때 보존 10일후 정자의 SAI와 생존율은 각각 0.3, $55.6\%$로 가장 좋았으며, 보존 7일후의 감성돔 알에 대한 수정률도 $47.7\%$로 혈청이 가장 좋았다. 정자를 pH $7\~8$의 희석액에서 보존하였을 때 가장 높은 SAI를 보였으며, 정자의 생존율과 SAI를 높이기 위한 항생제로는 neomycine(800ppm)이 효과적인 것으로 나타났다.

• 한국수산과학회지
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• 제50권5호
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• pp.527-533
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• 2017

We investigated the infection of nervous necrosis virus (NNV) in seven band grouper Hyporthodus septemfasciatus broodstocks, which have been reared in aquaculture farms in South Korea during 2012-2014. To investigate the prevalence of NNV within the broodstock, egg, sperm, and blood were sampled in the spawning season. The egg and sperm samples were subjected to a nested reverse transcription (RT) polymerase chain reaction (PCR) assay to detect NNV and were inoculated on SSN-1 cells to culture the virus. Blood samples were used to detect antibodies against NNV using enzyme linked immunosorbent assay (ELSIA). Positive values from ELISA were found in 39 of 162 samples (24%) in 2012, and 13 of 28 samples (46%) in 2014. Additionally, 4 of 34 broodstocks (11%) investigated in 2013-2014 were determined to be carriers from the nested RT-PCR and in vitro cultivation. The broodstocks in which antibodies against NNV were detected by ELISA, or in which NNV was detected by the nested RT-PCR assay, posed a risk of vertical transmission of NNV. Therefore, it is necessary to select virus-free broodstocks in seed production to reduce the possibility of the vertical transmission of NNV.

• 한국양식학회지
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• 제11권1호
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• pp.67-75
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• 1998

감성돔 (Acanthopagrus schlegeli) 정자의 냉동 보존시 정자의 생리활성과 보존효과를 비교하기 위하여, 순환여과 사육시스템에서 사육한 전장 $25.9{\pm}1.7$ cm, 체중$292.8{\pm}53.7$ g의 성어로부터 얻은 정액을 재료로 하여 희석액별, 동해방지제별 해동후 정자의 활성, 생존율 및 알에 대한 수정능력을 평가하였다. 희석액별 냉동보존에서 해동정자의 생존율은 3% sodium citrate에서 $80{\pm}1.4$%로 가장 높았으나, 수정률은 5.4% glucose에서 $63.4{\pm}4.4$%로 가장 높았다. 동해방지제별 냉동보존에서 해동정자의 수정률은 5~15% glycerol을 동해방지제로 사용하였을 때, 50.1~69.4%로 DMSO 보다 나은 효과를 보였다. 감성돔 정자의 냉동보존을 위한 적정 희석액과 동해방지제는 5% glucose와 5% glycerol이었다. 냉동하지 않은 감성돔 정자의 머리는 구형으로 직경 $1.5{\pm}0.1$ ${\mu}$m, 길이 $1.3{\pm}0.1$${\mu}$m였으며, 치밀한 핵질로 채워져 있었다. 편모는 전형적인 9+2 구조를 나타냈다. 그러나 냉동후 해동시킨 정자중에서는 염색질의 과립화, 세포막의 이탈에 의한 그 용적이 커지는 구조변화를 보였다.

• 한국수산과학회지
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• 제37권6호
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• pp.478-484
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• 2004

On 11 June 1991, eggs from the brood stock of small yellow croaker (Larimichthys polyactis) were artificially fertilized using the standard dry method and were hatched. Each of the fertilized eggs (1.1-1.2 mm in diameter) had an oil globule and was transparent and buoyant. The fertilized eggs hatched in a range of water temperatures $(17.5-20.3^{\circ}C)$ 44 hrs after fertilization. The total lengths of the newly hatched larvae were 3.1-3.3 mm, and these hatchlings had 31 myotomes (10+21). Melanophores and yellow-brown chromatophores were concentrated on the head, at the ventral part of the yolk, and in the middle of the tail. Four days after hatching, the larvae completely absorbed the yolk and became flexions of 5.1-5.5 mm in total length. Fifteen days after hatching, one spine (the anterior tip of the maxillary) appeared in the upper jaw and three spines developed at the upper parts of the eyes and on the posterior part of the head. At this stage, the larvae were approximately 8.3 mm long. Thirty-nine days after hatching, juveniles (1.9-3.4 mm in total length) had a pointed tail fin. By 66 days after hatching, the juvenile fish (about 4.0-6.5 mm in total length) were similar to adult fish in body shape. The larvae of L. polyactis could be distinguished from those of L. croacea by two distinct characteristics: the large number of vertebrae (28-29), and a relatively small bony ridge on the occipital region of the head.

• 한국수산과학회지
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• 제41권6호
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• pp.471-477
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• 2008

Development of egg, larvae and juveniles for the Pacific mackerel, Scomber japonicus are described following natural fertilization in the indoor tank of $25^{\circ}C$ water temperature. Following a routine hormone treatment technique for the brood stock, male and female mackerels were artificially matured by intramuscular injections of LHRHa at a dosage of $400{\mu}g/kg$ body weight (BW)+Domperidone at a dosage of $4{\mu}g/kg$ body weight (BW) to induce maturation in a separate aquarium and induced natural spawning. Fertilized eggs were ca. 1.0 mm in diameter; spherical in shape with a single oil globule; pelagic and non-adhesive. Hatching occurs 41 hours after fertilization at $23-24^{\circ}C$. The newly hatched larvae was 3.03 mm in average total length (ATL), the mouth and anus were not open, oil globule located in posterior end of yolk sac, and preanal length was 42.8% of TL. The larvae measuring 2.89 mm ATL, almost absorbed yolk sac and oil globule material in 2 days after hatching, in which the mouth and anus were open. Melanophores, branch or star in shape were observed on the top of head, peritoneal region and along the ventral contour. In 13 days after hatching, the larvae was 6.88 mm ATL, its posterior end of notochord began to flex upward, finfold of caudal fin appeared, jaw teeth were already formed. In 19 days after hatching, the larvae was 7.71 mm ATL completed only caudal fin rays (9+8), and preanal length was 49.4% of TL. In 37 days after hatching, the larvae was 27.4 mm ATL already completed all the fins, and preanal length was 59.9% of TL.