• 수산해양기술연구
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• 제43권4호
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• pp.241-250
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• 2007

Fishes were caught by a bottom trawl in the Yeo-ja bay of Korea by every three month(March, June, September and December) and seasonal variation of abundance and species composition were studied in 2005. The catches were 1,187kg and were composed of 115 species with 20 hauls by 5 stations. The dominant species caught were Charybdis bimcaulata, Crangon hakodatei, Parapenaeus fissurus, Oratosguilla oratoria, and Thryssa purava. One hundred fifty species were identified as fish(38%), crustacea(20%), mollusca(4%) and others(38%) which including of Asterias amurensis. The amount of species was high in June and September and low in March and December. The diversity index(H') was about 1.2－2.5 and station similarity of fishes caught among the community was 0.009－0.230.

• 한국어병학회지
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• 제21권3호
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• pp.271-278
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• 2008

The epidemiological study was performed to survey the prevalence of 5 bacterial, 6 viral and 5 parasitic disease of cultured olive flounder, Paralichthys olivaceus in Pohang, Ulsan∙Gijang, Keoje and Wando area of Korea from February to December, 2007. The disease frequency of size groups were as follows; Among the 1,218 fish samples, less than 10 cm (67.6%), 11~20 cm (70.2%), 21~30 cm (73.4%), 31~40 cm (77.6%), above 41 cm (88.2%). The highest detection rates of pathogens were recorded in samples from August and Ulsan. The detection rates of parasites, bacteria or viruses were 43.2%, 38.8% and 24.4%, respectively. The distribution of specific diseases showed that detection rates of diseases occurring the most frequently during the study period were Trichodina (33.1%), viral nervous necrosis virus (16.0%), Vibrio (9.7%), Scutica (10.1%), Ichthyobodo (5.7%).

• 한국어병학회지
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• 제21권3호
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• pp.219-228
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• 2008

The effects of dietary yeast β-glucan administration on growth, nonspecific immune responses, serum lysozyme, skin mucous lysozyme, NBT (nitroblue tetrazolium) reduction by phagocytes, and disease resistance against Edwardsiella tarda in Japanese eel, Anguilla japonica were evaluated. Fish were fed the diets supplemented with 0%, 0.1% and 0.5% of yeast β-glucan to a commercial diet for 6 weeks. The body weight gain from the fish fed on the 0.5% supplemented diet for 6 weeks was significantly higher than the control. Both serum and skin mucous lysozyme were significantly higher in the all experimental groups except 2 weeks of 0.5% group. The bactericidal activity of serum was slightly increased at 6 weeks. Also, The intracellular superoxide anion production of kidney phagocytes was significantly higher in the all experimental groups. The diet supplemented with 0.1% were also found to raise the relative percent survival (RPS) of Japanese eel after an artificial challenge with 1×107 cells of Edwardsiella tarda per fish. The results suggested the potential of yeast β-glucan to activate some innate immune responses and to improve the growth in Japanese eel.

• 수산해양기술연구
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• 제45권4호
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• pp.287-291
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• 2009

This study examined the maturation and main spawning season of Japanese spear lobsters, Linuparus tirgonus(Von Siebold) captured around Jeju island from January to September, 2008. Carapace length(CL), body weight(BW) and gonad weight(GW) were measured. Gonadosomatic index(GSI) and sex ratio were calculated. In female group, CL showed the highest value in June and decreased after August. GW showed a peak in July and decreased rapidly after August. The mean gonadosomatic Index(GSI) reached a maximum value between June and August. Number of egg ranged from 143,360 to 189,504.

• 수산해양기술연구
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• 제45권2호
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• pp.122-127
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• 2009

A series of fishing experiments was carried out in the eastern coastal waters of Korea from January, 2002 to March, 2003, using gill nets of different mesh sizes (m 180, 210, 240, 270 and 300 mm) to determine the size selectivity of gill net for female snow crab, Chionoecetes opilio. The catch of experimental gears was mostly snow crab (97%), Chionoecetes opilio. The maximum carapace length (RL) of each female snow crab caught in the fishing experiments was measured. The master selection curve was estimated by applying the extended Kitahara s method. The selection curve showed that the gill nets of larger mesh size allowed more female crabs of small carapace size to escape. The optimum values of RL/m for 1.0 of retention probability was 0.563 and RL/m was estimated to be 0.249, 0.290, 0.319, 0.344 and 0.367 when the retention probability were 0.1, 0.2, 0.3, 0.4 and 0.5, respectively.

• 한국어병학회지
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• 제23권1호
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• pp.123-129
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• 2010

2006년부터 2008년까지 국내로 회귀하는 연어(O. keta)의 소상위치, 암수 및 근육 부위별 아니사키스형 유충의 감염상을 조사하였다. 3년 동안강에서 채집된 연어 17마리와 바다에서 채집된 13마리의 아니사키스형 유충의 감염율을 조사한 결과, 강에서 채집된 연어의 수컷 및 암컷은 마리 당 아니사키스형 유충이 각각 평균 $98{\pm}27$ 및 $103{\pm}27$ 마리씩 감염되어져 있었다. 바다에서 채집된 연어의 수컷 및 암컷은 마리 당 아니사키스형 유충이 각각 평균 $63{\pm}18$ 및 $108{\pm}17$ 마리씩 감염되어져 있었고, 암수 및 소상위치간의 아니사키스형 유충의 감염 마리수에서 통계학적 차이는 없는 것으로 나타났다. 아니사키스형 유충의 근육 부위별로 조사하면 복강내측근육 (abdominal muscle)에 85%가 기생하며, 내장기관에는 거의 유충이 발견되지 않았다. 동정된 아니사키스형 유충은 Anisakis type이 74%며, 나머지는 Contracacecum type로 분류되었다. 연어 근육내에서 아니사키스형 유충의 저온처리에 따른 생존율을 조사하였을시에 최소 6시간 이상의 냉동보존 ($-20^{\circ}C$)만이 아니사키스형 유충이 죽는다는 사실을 알 수 있었다.

• 한국어병학회지
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• 제26권3호
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• pp.163-171
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• 2013

PCR (polymerase chain reaction) 법은 신속하고 정확하여 바이러스성 질병진단을 위해 널리 사용되지만 조직병리학적인 정보를 제공하지 못한다. 반면에 in-situ hybridization (ISH) 법을 사용하면 바이러스를 빠르게 검출할 수 있을 뿐 아니라 조직에서의 분포도 알 수 있다. 본 연구에서는 RSIV, VHSV, 그리고 VNN 바이러스들의 조직내 분포 및 조직 병리학적인 특성을 확인하기 위하여 이 바이러스들에 감염된 에 감염된 양식 넙치의 어류의 다양한 조직들을 대상으로 ISH 법을 적용하였다. 그 결과 이들 세 종류의 바이러스가 각각 다른 조직 및 세포들에 감염함을 확인 할 수 있었다. 본 연구 결과는 ISH법이 어류 병원성 바이러스의 신속 검출 뿐 아니라 조직 병리학적인 특성 확인에도 유용함을 제시한다.

• 수산해양기술연구
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• 제46권2호
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• pp.157-163
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• 2010

The indirect target strength (TS) estimation method which uses the Kirchhoff ray mode model (KRM model) was discussed to apply for a biomass estimation in the water of mixed species. TS of 25 live scorpion fishes for 120kHz were measured by a tethered method and of others dominant 5 species in the marine ranching ground of Jeju coastal water including a scorpion fish were also estimated by KRM model. The measurement TS of scorpion fish well agreed with the theoretical values and the standard formula of scorpion fish was estimated as $TS_{120kHz}=20Log\;(L)-72.9$ ($r^2=0.67$). TScm values estimated on trial to each sample of dominant 5 species were from -69.3dB to -75.1dB at 120kHz and they were in the general range of swimbladdered fish. It was clarified that TS by KRM model can be used to estimate fish biomass estimation by increasing a sample number and is more effective under the condition that there is rare TS information for inhabiting species in mixed-species area.

• 한국수산과학회지
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• 제43권5호
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• pp.532-539
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• 2010

Seaweed biomass was estimated in the rocky subtidal zone of Daejin on the mid-east coast of Korea using a destructive sampling method from February to November 2007. Monthly sampling was conducted at depths of 5, 10 and 15 m using 50 $\times$ 50 cm quadrats. A total of 73 species, including 5 chlorophytes, 25 phaeophytes, 43 rhodophytes and one seagrass were identified. Average seaweed biomass was 2,852.3 g wet wt. $m^{-2}$ and biomass values varied monthly from 1,189.8 g to 7,523.7 g. The species dominant in biomass were Laminaria japonica (481.7 g), Sargassum confusum (470.85 g), Undaria pinnatifida (422.57 g), Costaria costata (282.16 g), Odonthalia corymbifera (174.46 g), S. sagamianum (163.22 g) and S. horneri (122.18 g). The vertical distribution of algae was characterized by S. confusum and U. pinnatifida at 5 m, L. japonica and U. pinnatifida at 10 m, and O. corymbifera and L. japonica at 15 m depth. The C/P, R/P and (R+C)/P values were 0.20, 1.72 and 1.92, respectively.

• Fisheries and Aquatic Sciences
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• 제15권2호
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• pp.151-155
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• 2012

We used nine microsatellite DNA markers to estimate genetic variation among wild and cultured populations of the sea squirt Halocynthia roretzi. The loci were polymorphic, with 6-32 alleles, and allelic richness ranged from 6.0 to 26.1 in each population. The wild and the cultured populations had similar mean heterozygosities ($H_O$ and $H_E$), allele numbers, and allelic richness. One cultured population with softness syndrome had a lower mean in the observed heterozygosity ($H_O$ = 0.57) and higher mean inbreeding coefficient ($F_{IS}$ = 0.261) than any other populations. This suggests that the loss of genetic variation in the diseased population might be due to increased inbreeding. A neighbor-joining tree and pairwise population estimates of $F_{ST}$ showed moderate genetic differentiation between the wild and the cultured populations. Additionally, the softness syndrome population was genetically divergent from wild populations, but it was genetically close to the cultured populations.