• 한국해양생명과학회지
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• 제2권1호
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• pp.1-6
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• 2017

본 연구의 목적은 능성어와 자바리의 정자동결을 위한 간편한 실험법개발이다. 희석제와 동해방지제가 정자동결에 미치는 효과를 파악하고자 운동성성과 생존율을 조사하였다. 동결실험에서 300 mM glucose와 15% dimethylsulfoxide (DMSO)를 희석제와 동해방지제로 각각 사용하였다. 동결실험결과, 능성어 정자는 동결 5개월 후 60% 이상의 운동성을 보였고, 자바리 정자는 동결 5개월후 90% 이상의 운동성을 보였다.

• 한국수산과학회지
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• 제53권4호
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• pp.479-485
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• 2020

We evaluated the hatchability of fertilized eggs from six hybrid combinations of highly valued grouper species inhabiting temperate and warm waters, with the goal of establishing a novel hybrid with enhanced growth and viability during the culturing period in the temperate waters of Korea. Hybrid combinations with red-spotted grouper females exhibited high hatchability with high a fertilization and hatching rate of fertilized eggs and a low deformity rate of hatched larvae. Conversely, hybrid combinations with kelp grouper females had very low hatching rates and very high deformity rates; commercial production of seed from such crosses would be difficult without improving hatchability. The hatchabilities of convict grouper ♀×giant grouper ♂ and kelp grouper ♀×red-spotted grouper ♂ were lower than those of maternal purebreds, but these two hybrid combinations were expected to produce potentially large quantities of hatched larvae. In the above evaluation, promising hybrid combinations were identified for commercial production of seed. For these hybrids to contribute to the development of Korea's mariculture industry, mass production of fertilized eggs and seeds is necessary, along with the development of advanced rearing techniques, such as the identification of a suitable rearing temperature.

• 한국어류학회지
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• 제27권1호
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• pp.16-20
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• 2015

서식 환경이 다른 바리과(family Serranidae) 어류 두 종, 붉바리 (Epinephelus akaara)와 brown-marbled grouper (E. fuscoguttatus)의 종간 잡종 수정란의 부화율을 조사하였다. 잡종(붉바리 ♀ ${\times}$ brown marbled grouper ♂)의 수정 후 각 발생단계까지 소요시간은 붉바리 순종과 차이가 없었으며, 부화 소요시간은 $25^{\circ}C$에서 25.6시간이었다. 잡종은 붉바리 순종과는 달리 비균등 난할이 분명하게 관찰되었다. 잡종의 부화율은 네 수온(22, 25, 28, $31^{\circ}C$)에서 대체적으로 낮았으며, $25^{\circ}C$에서 9.8%로 가장 높았다. 이상의 연구에서 서식환경이 서로 다른 바리과 두 종간 잡종이 생산 가능한 것으로 조사되었으며, 향후 산업적 활용성을 검증하기 위하여 발생 양상, 기형률 및 초기 생존율 등에 관한 면밀한 연구가 필요할 것으로 판단된다.

• 수산해양기술연구
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• 제35권4호
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• pp.391-396
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• 1999

It is well known that fish hear a wide frequency range of sound using both laterial line and inner ear, and the sound is probably the most effective channel for long-range communication underwater than any other stimulus.The auditory threshold of svenband grouper, Epinephelus septem fasciatus was determined by conditioning method using a sound coupled with electric shock in a tank. The audio-signals and electric shock used in the experiment were pure tones of 100 to 1000Hz and DC 6n.The response of fish to the sound was observed by ECG intervals from precordial leads method (V1·V2 method). The auditory threshold curve for sevenband grouper was V-shaped, with most sensitive threshold at 350Hz in the range of 100~1000Hz. The Sevenband grouper were more sensitive to sounds of 200~400Hz than to adjacent frequencies.

• 한국해양생명과학회지
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• 제7권2호
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• pp.139-144
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• 2022

본 연구는 붉바리 어미의 사육환경에 따른 난질의 변화를 난의 생화학적 분석을 통하여 난질에 영향을 미칠 수 있는 요소를 구명하기 위하여 수행하였다. 그 결과 육상수조에서 사육하는 것보다 해상가두리에서 사육할 때 부상률, 수정률, 난 발생 생존율 및 부화율이 우수하였다. 그리고 해상가두리에서 생산한 수정란의 유리아미노산의 함량이 높았다. 즉, 해상가두리에서 사육관리할 때 난질이 우수한 수정란을 생산할 수 있고, 난질이 우수할수록 유리아미노산의 함량이 높았다.

• Fisheries and Aquatic Sciences
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• 제22권12호
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• pp.28.1-28.8
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• 2019

Background: In the present study, we evaluated four commonly used housekeeping genes, viz., actin-β, elongation factor-1α (EF1α), acidic ribosomal protein (ARP), and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as internal references for quantitative analysis of immune genes in nervous necrosis virus (NNV)-infected seven-band grouper, Hyporthodus septemfasciatus. Methods: Expression profiles of the four genes were estimated in 12 tissues of healthy and infected seven-band grouper. Expression stability of the genes was calculated using the delta Ct method, BestKeeper, NormFinder, and geNorm algorithms. Consensus ranking was performed using RefFinder, and statistical analysis was done using GraphpadPrism 5.0. Results: Tissue-specific variations were observed in the four tested housekeeping genes of healthy and NNV-infected seven-band grouper. Fold change calculation for interferon-1 and Mx expression using the four housekeeping genes as internal references presented varied profiles for each tissue. EF1α and actin-β was the most stable expressed gene in tissues of healthy and NNV-infected seven-band grouper, respectively. Consensus ranking using RefFinder suggested EF1α as the least variable and highly stable gene in the healthy and infected animals. Conclusions: These results suggest that EF1α can be a fairly better internal reference in comparison to other tested genes in this study during the NNV infection process. This forms the pilot study on the validation of reference genes in Hyporthodus septemfasciatus, in the context of NNV infection.

• 한국수산과학회지
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• 제49권5호
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• pp.612-619
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• 2016

In this study, we crossbred Epinephelus akaara and E. lanceolatus to produce a hybrid grouper with faster growth and adaptation to domestic aquaculture environments. The plasma cortisol and glucose levels and osmoregulation (stress response indicators) of the hybrid grouper, E. akaara ♀ × E. lanceolatus ♂, were investigated under several salinity levels (32, 24, 16, and 8 psu). The body lengths and weights of E. akaara (8.2 ± 0.1 cm, 8.3 ± 0.4 g) and the hybrid (8.6 ± 0.1 cm, 10.0 ± 0.4 g) were similar at the start of the experiment, but were significantly different at the end of the experiment. Juveniles of both E. akaara and the hybrid showed greater weight gain, specific growth, and feed conversion rate (FCR) under low salinity of 16 psu. Under the 8 psu treatment, the juvenile E. akaara all died, while the hybrid juveniles survived. Plasma cortisol levels were not affected by lower salinity in both species. The above results indicate that the hybrid is more tolerant of low salinity than is E. akaara, although both species exhibited higher growth and FCR at 16 psu, lower than the salinity of natural seawater. Thus, juveniles of both E. akaara and the hybrid can be more effectively cultured in brackish areas or waters with salinity lower than that of seawater.

• 수산경영론집
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• 제36권2호
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• pp.121-134
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• 2005

In order to evaluate the effectiveness of management measures and to provide policy suggestions for the allocation of total allowable catch between recreational and commercial sectors, the economic value of red grouper recreational fishery in the United States Gulf of Mexico was estimated using a Travel Cost Method(TCM), Due to the characteristic of count data, a Poisson model(PM) and a Negative binomial model(NBM) were used in the TCM. Results of models showed that the NBM was statistically more suitable than the PM since the overdispersion problem occurred in the PM. Results also indicated all signs of the estimated parameters were as expected and were significant, except for a Boat parameter in both models. Based on the results of NBM, the total economic value of the recreational red grouper fishery was estimated to be $\$698.6$ and the value per trip was $\$179.5$. In addition, the total changes in expected consumer surplus due to changes in catch rates was $ \$42.3$.

• Animal cells and systems
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• 제16권1호
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• pp.50-56
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• 2012

Kelp grouper ($Epinephelus$ $bruneus$ Bloch 1793) is a commercially important fish in Korea. In recent years, the catch of kelp grouper in the coastal waters of Korea has significantly declined. Despite its importance, little is known about its genetic diversity and conservation efforts are hampered. In this study, we isolated and characterized 12 microsatellite loci using an enrichment method based on magnetic/biotin capture of microsatellite sequences from a size-selected genomic library. All loci were readily amplified and contained TG/CA denucleotide repeats. To characterize each locus, 30 individuals from a natural E. bruneus population in the coastal waters of Jeju Island, Korea, were genotyped. All loci except three, KEm118, KEm154, and KEm219, were polymorphic, with an average of 8.1 alleles per locus (range 2-18). The mean observed and expected heterozygosities were 0.47 (range 0.19-1.00) and 0.61 (range 0.29-0.92), respectively. A significant deviation from Hardy-Weinberg equilibrium was observed at three loci (KEm134, KEm184, and KEm283). These findings will be useful for effective monitoring and management of genetic variation of kelp grouper as well as for the implementation of a fisheries conservation program.

• 수산해양교육연구
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• 제27권4호
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• pp.981-989
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• 2015

This study aims to investigate how ovulation induction of sevenband grouper, Epinephelus septemfasciatus varies when treated with different hormonal substances such as ovaprim, pimozide, LHRHa, and HCG. As for LHRHa, we injected it in different concentrations: $50{\mu}g/kg$, $100{\mu}g/kg$, $150{\mu}g/kg$, and $200{\mu}g/kg$. All hormonal substances including LHRHa were injected into back muscles. As a result, ovulation occurred in all sample groups. The sample group injected with HCG released the largest amount of eggs, and the dimeter of eggs and oil globules were also significantly bigger than those of others. Fertilization rate, embryonic survival rate, and hatching rate were the highest in a LHRHa ($100{\mu}g/kg$) +pimozide ($1,000{\mu}g/kg$) group and buoyant rate in a LHRHa group. Ovulation rate was 100% when LHRHa was injected in different concentrations. The largest amount of eggs was released in $200{\mu}g/kg$. The diameter of eggs and oil globules were the biggest in $200{\mu}g/kg$ and the smallest in $50{\mu}g/kg$. Fertilization rate showed no significant difference through all different levels of concentration: 94.6-95.3%. Buoyant rate was the highest in $100{\mu}g/kg$ and embryonic survival rate and hatching rate in $150{\mu}g/kg$. Based on these experimental results, we concluded that LHRHa in $100{\mu}g/kg$ is the most efficient for the ovulation induction of sevenband grouper.