• Parasites, Hosts and Diseases
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• 제49권1호
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• pp.39-44
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• 2011

The infection status of marine fish and cephalopods with Anisakis simplex third stage larva (L3) was studied over a period of 1 year. A total of 2,537 specimens, which consisted of 40 species of fish and 3 species of cephalopods, were purchased from the Cooperative Fish Market in Busan, Korea, from August 2006 to July 2007. They were examined for A. simplex L3 from the whole body cavity, viscera, and muscles. A. simplex L3 were confirmed by light microscopy. The overall infection rate reached 34.3%, and average 17.1 larvae were parasitized per infected fish. Fish that recorded the highest infection rate was Lophiomus setigerus (100%), followed by Liparis tessellates (90%), Pleurogrammus azonus (90%), and Scomber japonicus (88.7%). The intensity of infection was the highest in Gadus macrocephalus (117.7 larvae per fish), followed by S. japonicus (103.9 larvae) and L. setigerus (54.2 larvae). Although abundance of A. simplex L3 was not seasonal in most of the fish species, 10 of the 16 selected species showed the highest abundance in February and April. A positive correlation between the intensity of L3 infection and the fish length was obvious in S. japonicus and G. macrocephalus. It was likely that A. simplex L3 are more frequently infected during the spring season in some species of fish. Our study revealed that eating raw or undercooked fish or cephalopods could still be a source of human infection with A. simplex L3 in Korea.

• 한국어류학회지
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• 제18권2호
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• pp.129-140
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• 2006

제주도 서부 해역에서 어류 난 자치어의 계절별 출현현황을 조사하기 위해 2004년 9월부터 2005년 8월까지 총 5회에 걸쳐 각 계절별로 난 자치어를 채집하였다. 조사기간 동안 난과 자치어는 모두 여름철인 8월에 가장 많이 출현하고 있었다. 본 연구해역에서 조사기간 동안 출현한 전체 자치어는 총 10목 26과 51속 59종으로 이들 중 농어목 어류가 15과 41종으로 가장 많이 출현하였고, 다음으로 쏨뱅이목 2과 7종, 큰가시고기목 2과 2종의 순으로 출현하고 있었다. 계절별 자치어 출현현황에 있어서 출현종수는 8월에 25종으로 가장 많이 출현한 반면에 5월에 6종으로 가장 적은 출현종수를 나타내고 있었다. 계절별 자치어 출현량에 있어서 고수온기인 여름철에는 주로 멸치, 고등어류와 같은 회유성 어종들이 풍부하게 출현하여 우점을 이루고 있는 반면에 저수온기인 겨울철에는 쏨뱅이, 볼락과 같은 정착성 어종들이 우점을 이루고 있었다.

• Fisheries and Aquatic Sciences
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• 제14권1호
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• pp.55-61
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• 2011

Fish larvae were collected monthly with an ichthyoplankton net from 18 stations (including four stations located in eelgrass beds) in Gamak Bay and Yeoja Bay, southern Korea, in 2007. In total, 33 species of fish larvae were collected, of which Engraulis japonicus (48.5%), Tridentiger trigonocephalus (21.5%), and Omobranchus elegans (9.2%) were dominant. Dominant species varied seasonally: Hexagrammos otakii during December and January, Pholis nebulosa during January and March, Acanthogobius flavimanus in April, T. trigonocephalus in May, E. japonicus during June, July, September, and November, and Sillago japonica in August. Dominant species also differed between sites inside and outside the bays. Leiognathus nuchalis, O. elegans, and T. trigonocephalus were more abundant inside, while H. otakii was more abundant outside. From cluster analysis, three groups were identified according to sampling months (January-April, May-September, and October-December) and two groups according to station (inside and outside bays). The occurrence of small larvae of almost all major fish species indicated that the bays were used as spawning and nursery grounds. An exception was Lateolabrax japonicus, whose specimens were relatively large (>19 mm TL), suggesting that this fish may spawn offshore, with its juveniles approaching the bays with growth.

• Parasites, Hosts and Diseases
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• 제52권4호
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• pp.383-389
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• 2014

Anisakiasis, a human infection of Anisakis L3 larvae, is one of the common foodborne parasitic diseases in Korea. Studies on the identification of anisakid larvae have been performed in the country, but most of them have been focused on morphological identification of the larvae. In this study, we analyzed the molecular characteristics of 174 Anisakis type I larvae collected from 10 species of fish caught in 3 different sea areas in Korea. PCR-RFLP and sequence analyses of rDNA ITS and mtDNA cox1 revealed that the larvae showed interesting distribution patterns depending on fish species and geographical locations. Anisakis pegreffii was predominant in fish from the Yellow Sea and the South Sea. Meanwhile, both A. pegreffii and A. simplex sensu stricto (A. simplex s.str.) larvae were identified in fish from the East Sea, depending on fish species infected. These results suggested that A. pegreffii was primarily distributed in a diverse species of fish in 3 sea areas around Korea, but A. simplex s.str. was dominantly identified in Oncorhynchus spp. in the East Sea.

• Parasites, Hosts and Diseases
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• 제35권1호
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• pp.19-24
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• 1997

The infection status of anisakid larvae was examined in 290 marine fish of 25 species and in 108 cephalopods of 3 species purchased in Bayuquan region, Yingko city nearby the coast of the Bohai Sea from may to August 1992. A total of 7,327 laivae were collected from 156 fish of 19 species and 8 squids of one species. The 3rd-stage larvae of Anisokis simplex were collected from 121 fish (63..4%) of 15 species (N : 191) and from 8 squids (14.8%) of one species (N : %4), and they were total, 5,992 (81.8%). Out of remaining 1,335 larvae, 154 (2.1%) were classified as Rvnnqscnris type B from 23 fish of 4 species, 1,013 (13.8%) as avnnosccris type C from 79 fish of 13 species, 164 (2.2%) as Hvsterothylacium China type V from 20 fish of 4 species, 3 (0.04%) as Raphinoscnris from 3 fish of 2 species and one was Pseunotewonovc necipiens larva. Key words: Bohai Sea, Anisokinae, larvae , Anisckis, HvsterothWLacium, Thwnnascaris, Raphinqscaris , Pseudoterranova.

• 한국수산과학회지
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• 제36권5호
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• pp.486-494
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• 2003

Distribution of ichthyoplanktons and its relation to environmental factors (temperature, salinity, $chlorophyll\;\alpha$) around the Youngsan River Estuary of Mokpo, southwest coast of Korea were investigated based on the samples collected bimonthly from February to December, 2001. Unidentified fish eggs were most abundant $1,345\;eggs/100m^3$ in August, while eggs of Engraulis japonicus were most abundant $63\;eggs/100m^3$ in June. A total of forty species of fish larvae and juveniles belonging to the twenty families under six orders were caught, with six gobiids, four icefishes, four croakers and three herrings being represented. Fish larvae and juveniles peaked $17,757\;inds./100m^3$ in August, which consisted of $91.02\%$ of gobiids, $3.69\%$ of gunnels and $3.67\%$ of icefishes, and they were most abundant $7,467\;Inds./100m^3$ at St. 7. Cluster analysis based on the individuals of fish larvae and juveniles showed that six months were classified into two groups at the dissimilarity 70, the first was composed of June and August and the second was February and December and April and October were not clustered with any other months. In August when species diversity index was the highest, eight stations were classified into two groups at the dissimilarity 70, the first was composed of St. 1, 3, 4, 5 and 8 and the second was St. 6, 7 and 2. As a result from correspondence analysis, there is no effect of the environmental factors with a density of fish eggs and larvae, but correlation could be found between a density of fish eggs and $chlorophyll\;\alpha.$

• 한국수산과학회지
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• 제38권1호
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• pp.29-38
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• 2005

The distributions of fish larvae and juveniles from the East China Sea, Yellow Sea and near Tsushima Island were investigated in Spring using the Maruchi (1994-1995) and Unagi (1996-1997) nets. A total of 94 species of fish larvae and juveniles belonging to 49 families under 17 orders were identified, of which Engraulis japonicus was dominant in every year except 1995 where Trachurus japonicus was dominant. Cluster analysis based on abundance and species composition by sampling stations (St.) revealed that the similar stations formed an arcuate group from Tsushima Island to southern Jeju Island in 1994, and from the Yellow Sea to southern Jeju Island in 1996. We concluded that these patterns resulted from the influence of the Tsushima Current prevailing in the east, and the Chinese Continental Waters and/or Hwanghae Cold Waters prevailing in the west, with Jeju Island exerting an influence in the centre. The diversity and composition of St. 97-3 and St. 97-5, both located where the Tsushima Current splits from the Kuroshio Current, was greatly different despite their close proximity. However, the former is located on the continental shelf, with the latter on the continental slope. This suggested that both topography and the Kuroshio Current have the most influence on the distribution of fish larvae and juveniles in this region. Furthermore, the weak Hwanghae Cold Waters of 1997 may have also limited the mixing of fish larvae and juveniles between the two stations.

• 한국수산과학회지
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• 제53권6호
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• pp.900-908
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• 2020

This study was conducted to partially replace fish meal with black soldier fly (BSF) larvae or mealworm (MW) larvae in the diet for Pacific white shrimp Litopenaeus vannamei. A tuna by-product meal (27%) was used as the protein source in a control (Con) diet, which was replaced with 20%, 40%, or 60% BSF (designated as BSF20, BSF40, and BSF60, respectively), or MW (MW20, MW40, and MW60, respectively). The shrimp (average body weight, 0.09 g) were randomly stocked in 28 acrylic tanks and quadruplicate groups were fed one of the experimental diets six times daily. After 57 days of the feeding trial, growth and feed efficiency were significantly higher in shrimp that were fed the BSF40 and BSF60 diets than those in shrimp fed the Con diet. Phenoloxidase, superoxide dismutase, glutathione peroxidase and gene expression of crustin were significantly higher in shrimp fed BSF or MW diets than those in shrimp fed the Con diet. The results indicate that BSF or MW could be used as a fish meal replacement or as a functional protein source in diets and can help improve the growth, feed utilization, innate immunity and antioxidant capacity of Pacific white shrimp.

• 한국수산과학회지
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• 제37권1호
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• pp.7-12
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• 2004

This study investigated the possibility of salinity acclimation of freshwater rotifers (Brachionus calyciflorus) as live food for sweetfish (Plecoglossus altivelis) larvae, and also examined the optimal salinity for the growth of sweetfish. Freshwater rotifers cultured in 0 and 4 PSU and seawater rotifers (B. rotundiformis) cultured in 33 PSU were supplied to the larvae with four kinds of enrichment material (condensed freshwater Chlorella, $\omega-yeast,$ baker's yeast, Super Selco) and larval growth at 4 PSU was examined. Growth of the freshwater rotifers positively increased from 0 PSU to 6 PSU, but decreased when over 8 PSU was reached. Growth and survival of the sweet fish larvae reared in 0 PSU were significantly lower than those reared in either 4 PSU or 33 PSU. This indicated that the freshwater rotifers (B. calyciflorus) could be used as live food for sweetfish larvae reared in 4 PSU. The body weight of sweetfish larvae fed on freshwater rotifers enriched with Super Selco was the highest at 0.163 mg, but there was no significant difference in survival and body length of the fish fed with the other enrichment materials. The content of n-3 HUFA of the sweetfish larvae fed on the freshwater rotifers enriched with Super Selco and the condensed freshwater Chlorella was higher than that enriched with $\omega-yeast$ and baker's yeast. These results indicated that B. calyciflorus cultured with the condensed freshwater Chlorella could be used for the sweetfish larvae without enrichment, and the most efficient enrichment material for B. calyciflorus is Super Selco.

• 한국양식학회:학술대회논문집
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• 한국양식학회 2003년도 추계학술발표대회 논문요약집
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• pp.93-94
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• 2003

To investigate the food organisms of the Acentrogobius elongata during the juveniles stage, the stomach contents of fish, captured in the intertidal zone of Chungchongnam-do Sochon-gun Su-myon Dodun-ri between on early in June from the end of May 2000, were observed. Total length of the fingerings of A. elongata was 1.0~3.0cm size, and the participation rate of feeding was 68.6%. Main food organisms were such as copepods, shrimp larvae, polychaete larvae, and these occupied more than dry weight 4%. Copepods among them dominated the most quantitys by average 64.6%, and food organismsms appeared by order of polychaete larvae and shrimp larvae etc.. Therefore, most important food organisms of fingerlings stage of A. elongata were copepods, polychaete larvae, shrimp larvae etc.