• Journal of fish pathology
• /
• v.17 no.1
• /
• pp.1-10
• /
• 2004

In order to analyse the detection of viral hemorrhagic septicemia virus (VHSV) in marine environment surrounding coastal region of Eastern and Southern sea of Korea, the pools of each organ sample of three fish were taken for virus assay from February to May in 2003. The samples comprised 42, taken from 9 species of marine fishes. The VHSV was detected from chub mackerel Scomber japonicus and striped mullet Mugil cephalus in epithelioma papulosum cyprini (EPC) cells. The identity of the virus was confirmed a reverse transcriptase-polymerase chain reaction (RT-PCR). VHSV has previously been reported from chub mackerel, but not from striped mullet. The new isolates was classified as a member of genogroup I (American type) of VHSV and was closely related to the VHSV KVHS'01-l based on comparisons of the partial nucleotide sequence of the glycoprotein (G) gene.

• Journal of fish pathology
• /
• v.36 no.2
• /
• pp.403-408
• /
• 2023

Mullet is an important marine aquaculture fish species in Korea, with a total of 7,237 tons produced as of 2022, making it the 5th most produced marine aquaculture fish species. In this study, ectoparasites presumed to be isopods were discovered in the fins of farmed flathead grey mullet (average weight 550 g), and the characteristics of the parasites were confirmed. The length of the parasite was 5 to 18 mm, and 3 to 7 parasites were infected per fish. To analyze the characteristics of the parasites, molecular biological identification and phylogenetic analysis were performed using the cytochrome c oxidase subunit I (COI) gene, and it was confirmed to be most closely related to Nerocila japonica in the Cymothoidae family. To confirm the parasite control effect, a direct exposure drug sensitivity test was conducted on five types of aquatic drugs and fresh water, trichlorfon was confirmed to be effective.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.30 no.4
• /
• pp.283-291
• /
• 1994

This paper describes about the behavior of the Striped mullet (Mugil cephalus) in the setnet by telemetry techniques. The telemetry system consists of a pinger of 50KHz, three omni-directional hydrophones and ultrasonic receivers, a single board computer for the signal processing, two RF transceivers for the data comunication and a personnel computer. The fish tagged the pinger was tracked by the LBL method, and its location was calculated by the hyperbolic method. The fish escaped from sea surface to 7m deep right after release and had been swum near the sea surface after 30 minutes being released. Also, in horizontal movements, the fish stayed long time around the enterance of the square net in setnet, and showed the escaping behavior repeatly. The average speed of the fish was about 0.41m/sec(1.1 times of the body length)

• Journal of fish pathology
• /
• v.16 no.1
• /
• pp.31-38
• /
• 2003

The mortality of wild mullet, Mugil cephalus was detected in Kwang- Yang bay on February, 2002. The mullet were infected with Myxobolus sp., the cysts of Myxobolus sp. were found in the mesentery, liver, gill and pharyngeal pocket. The histological findings suggested a systemic infection by the Myxobolus sp.. The spores were measured 10-12 (10.9)${\mu}m$ in length, 9-10 (9.4) ${\mu}m$ in width, 6.4-7.2 (6.8) ${\mu}m$ in thickness, with polar capsules of 4-5.2 (4.4) ${\mu}m$ in length and 2.5-3.3 (2.9) ${\mu}m$ in width.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2000.05a
• /
• pp.320-321
• /
• 2000

점농어, Lateolabrax maculatus는 담수적응력이 강할 뿐만 아니라 수온변화에도 강 특히 남해안과 서해안의 폐염전을 활용한 축제식 양식대상어종으로 선호하고 있는 실정이다. 다른 농어에 비해 성장이 빠르며 최근 인공종묘생산이 가능해짐에 따라 양식생산량이 증가하는 추세이다. 축제식 양식장어 적합한 점농어 전용사료가 개발되지 않아 대부분 숭어사료(Extruded Pellet, EP)를 급이 하거나 대만산 농어사료를 수입하여 급이 하고 있는 실정이다. 대만산 사료의 경우는 가격이 비싸 어민들이 기피하고 있는 설정이다. 점농어의 대량생산을 위해서는 이종에 적합한 EP사료가 개발되어야 할 것이다. 사료는 양식경영비의 절반이상을 차지하는 중요한 요소로 경제적이고 품질이 우수한 사료의 안정적 확보가 양식경영을 향상시킬 수 있다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2001.10a
• /
• pp.287-288
• /
• 2001

해산어류의 담수순화에 관한 연구는 일부 광염성 어종에 대해 수행되어 왔으나, 극히 미비한 실정이다 담수순화에 관한 연구는 아가미 구조적 연구, 내분비학적 연구 등이 연어과 어류의 회유시에 밝혀진 바 있다(Chen and Lin., 1994). 다른 해산어류의 삼투압조절 등 생리학적 연구는 숭어의 담수사육에 관한 기초연구 결과가 보고(장과 허, 1999)되고 있다. 그러므로 이러한 삼투압조절 능력 등이 실제 산업에 이용되려면 각각의 양식유용종에 대한 상세한 연구와 각 어종의 염분 내성, 삼투압조절 능력, 염분변화에 따른 생존 및 성장 그리고 삼투압조절 기능을 향상시키기 위한 물리적, 화학적, 생리학적 연구 등이 필요하다. (중략)

• The Journal of the Acoustical Society of Korea
• /
• v.3 no.2
• /
• pp.59-68
• /
• 1984

어군의 밀도를 음파로 추정할 때 어군의 총후방 산란 단면적이 어류개체의 후방 산란 단면적을 random phase로 합한 것과 같다는 가정에 대하여 실험적 검증을 시도하였다. 어체의 길이 대 음파의 파장비가 23일 때 두 마리와 세 마리의 숭어에 대하여 실시한 실험에서 전 산란각에 대한 편균이 random phase로 합할 때 보다 -1.7dB와 +1dB씩 편차를 보였다. 그러나 전체적으로는 in phase와 out phase sum 사이에서 변화함을 보였고, 최대오차는 in phase로 합해질 때로서 실제의 어군밀도 n에 비 해 최고 n\sup 2\에 이르기까지 추정 가능함을 실험결과는 보여주고 있다. 더욱이 이러한 결과는 어체간 의 간격변화에는 거의 무관하였으므로 소나무 빔폭이나 어군의 분포에 상관없이 빔폭 사이에 있는 어군 의 마리수에만 퐁후방 산란 단면적이 관계된다는 결론을 얻을 수 있었다.

• Korean Journal of Ichthyology
• /
• v.17 no.1
• /
• pp.64-72
• /
• 2005

The data for the present study were collected from the both-sides fyke net fishery in coastal Dolsan, Korea, from March 2003 to February 2004 A total of 2,402 individuals (432,42 kg) were collected and identified to 11 orders, 34 families, and 48 species. The most dominant order was the Perciformes, comprising 21 species in 15 families, followed by Scorpaeniformes, 8 species in 5 families, and Pleuronectiformes, 5 species in 3 families, These three orders constituted 67.9% of the total collected fish. The most dominant species, Acanthopagrus schlegeli, accounted for 279 individuals (20.26 kg), followed by Mugil cephalus with 187 individuals (99.61 kg), and Konosirus punctatus with 178 individuals (8.89 kg). The diversity index of the fish catches was 1.6823~2.9105 and was the highest in September 2003 and the lowest in December 2003. The evenness index was 0.6585~0.8872 it was the highest in August 2003 and the lowest in December 2003. The dominance index was 0.2000~0.6852, with the highest in December and the lowest in August 2003.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.19 no.1
• /
• pp.27-35
• /
• 1986

In succession to the previous paper, the present study was directed to investigate the effect of keeping freshness of conger eel (Astroconger myriaster) and yellowtail (Seriola quinqueradiata) by partial freezing, and the changes in the physical properties of fish meat paste product prepared with the muscle of conger eel during storage were also examined. The results obtained are summarized as follows: The period of keeping freshness (days in which k value reaches $20\%$) of conger eel and yellowtail by partial freezing was 10 days and 6 days, respectively. VBN content in the conger eel muscle showed 39.5 mg/100g by icing for 15 days, and did not show a great change by partial freezing and freezing, while that of yellowtail muscle reached at 32 mg/100g by icing, 20 mg/100g by partial freezing and 18 mg/100g by freezing for 15 days. The lipids extracted from the muscles of both fishes by icing were remarkably oxidized than those by partial freezing. The myofibrillar protein in the conger eel muscle during storage for 9 days decreased $3\%,\;10%\;and\;11\%$ by icing, partial freezing and freezing, respectively, and that of yellowtail muscle did $16\%,\;10%\;and\;4\%$ by icing, partial freezing and freezing, respectively. On the other hand, the alkali-soluble protein in both fishes increased with storage time. Gel strength of fish meat paste product prepared with the muscle of conger eel decreased to $35\%$ by icing, $74\%$ by partial freezing and $76\%$ by freezing for 10 days compared to control, and the expressible water increased 1.6 times, 1.2 times and 1.1 times by icing, partial freezing and freezing, respectively, as much as that of control product.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.27 no.5
• /
• pp.535-548
• /
• 1994

Community structures and fish densit were investigated on three different types of artificial reefs, dice, turtle artificial reef and tubes, constructed in the Korean waters. Variations of fish fauna according to type of artificial reef and the proper artificial reef in each area for optimizing harvest were discussed. Fish were captured by trammel gill net during May, June, September and November, 1988 and both identified and counted. Fourty-five fish species were found in the artificial reefs. Of these, Sebastes spp., Hexagrammos otakii, Pleuronectidae, Navodon modestus and Stephanolepis cirrhifer showed high occurrence-frequency. The dominant species groups were coastal settlement, demersal or rock fishes such as Pleuronectidae, Rajiformes, Stephanolepis cirrhifer, Navodon modestus, Hexagrammos otakii and Sebastes spp. in all of the Artificial reefs except the oceanic area of southern waters. Scomber japonicus was predominant in the oceanic area of southern waters. Composition of demersal, rock and pelagic fishes were different depending on the types of artificial reef. Dice artificial reefs were occupied by rock fish, on the other hand turtle artificial reefs were dominated by dermersal fish. Fish density was high at the dice artificial reef in all survey areas except the middle area of Eastern waters, with high fish density evident in the Tube artificial reef. Fish community structures were remarkably different between Dice and Turtle artificial reefs. The Tube artificial reef showed intermediate characteristics between the above two types of artificial reefs. The coastal areas of Southern waters and the middle and southern areas of Western waters revealed similar fish fauna. Results from the oceanic areas of Southern waters were well associated with the middle and southern areas of Eastern waters.