Phenotypic and genotypic analysis of <i>Edwardsiella tarda</i> isolated from olive founder (<i>Paralichthys olivaceus</i>) and Japanese eel (<i>Anguilla japonica</i>)

Park, Seong Bin,Nho, Seong Won,Jang, Ho Bin,Cha, In Seok,Lee, Jeong-Ho,Aoki, Takashi,Jung, Tae Sung Elsevier 2017 Aquaculture Vol.473 No.-

<P><B>Abstract</B></P> <P> <I>Edwardsiella tarda</I> is an important bacterial pathogen of olive flounder (<I>Paralichthys olivaceus</I>) and Japanese eel (<I>Anguilla japonica</I>). Here, a total of 66 strains of <I>E. tarda</I> isolated from olive flounder and Japanese eel were compared using biochemical tests, whole-cell protein analysis, lipopolysaccharide (LPS) profiling, and random amplified polymorphic DNA (RAPD) analysis to determine the host-related homogeneity of these pathogens. The <I>E. tarda</I> strains isolated from olive flounder were highly homogenous in the analyzed parameters, whereas the isolates from Japanese eel were highly heterogeneous. <I>E. tarda</I> isolated from Japanese eel did not demonstrate any pathogenic effect against olive flounder in challenge experiments. The phenotypic and genotypic homogeneity observed in the isolates from olive flounder may be helpful to develop an effective vaccine for edwardsiellosis in olive flounder.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>E. tarda</I> causes severe infections in olive flounders (<I>Paralichthys olivaceus</I>) and Japanese eel (<I>Anguilla japonica</I>). </LI> <LI> Phenotypic and genotypic analysis was performed for 66 <I>E. tarda</I> strains isolated from olive flounder and Japanese eel. </LI> <LI> <I>E. tarda</I> isolated from olive founder exhibited homogenous characteristics but not isolates from Japanese eel. </LI> <LI> The results may be helpful to develop the novel vaccine against <I>E. tarda</I> infection in olive flounder. </LI> </UL> </P>

극동산 뱀장어(Anguilla japonica)의 친자확인을 위한 유전자 마커 개발

노은수,신은하,박경현,김은미,김영옥,유용운,김신권,남보혜 한국수산과학회 2022 한국수산과학회지 Vol.55 No.5

The Japanese eel Anguilla japonica is a highly valued research object that is important for aquaculture in Asia, including the Republic of Korea. However, few studies have been conducted analyzing parentage using microsatellite markers derived from the Japanese eel. We acquired Japanese eel genome data using next generation sequencing technology, and constructed a draft genome comprising 1,087 Mbp. Using the Simple Sequence Repeat Identification Tool program, 444,724 microsatellites were identified. Of these, 1,842 microsatellites located in the 3' untranslated region, which are stably inherited, were finally selected. Ninety-six primers were selected to validate polymorphism at these microsatellites, and 9 primers were finally identified for multiplex analysis. Using multiplex polymerase chain reaction with three different fluorescence chemistries, we performed parentage analysis of an artificial Japanese eel population. CERVUS software was used to calculate the logarithm of the odds (LOD) scores and the confidence of the parentage assignments. The results presented here show that 83 out of 85 paternity cases were assigned at 95% confidence to a candidate father and mother with LOD scores ranging from 4.79 to 28.2. This study provided a microsatellite marker-based assay for parentage analysis of Japanese eels, which will be useful for selective breeding and genetic diversity studies.

장어 시판제품에 대한 동북아시아의 가공현황 및 일본인 소비자의 구매실태 조사

김혜영,임양이 한국조리과학회 2004 한국식품조리과학회지 Vol.20 No.5

TThis study investigated the current processing degree and ingredients of sauce on the packaging of the commercial eel products made in Northeast Asia (Korea, Japan, China and Taiwan) and surveyedthe perception of nutritional functionality and purchasing pattern of Japanese consumers for the processed eels. The results are considered as a useful aid for preparation of processed eel products. The commercial eel products, purchased at a department store, supermarket and discount market, were divided by processing method, package quantity, storage method and sauce ingredients. The processing method was indicated in many different ways in each country, such as sauce ingredients and intake method. A questionnaire survey was conducted on 105 Japanese consumers (male 43, female 62) visiting Korea. Of the respondents, 44% answered and the major reasons for purchasing processed eel products were as a side dish for meals. The results for this factor were significantly different in relation to age (p <0.05). The degree of perceptions of functional excellence about processed eel products was well known (37%), some (49%), and seldom (14%). The results for this factor were significantly different in relation to age (p <0.001). Seventy-five percent of the respondents had experienced processed eel products. The type of purchase of the respondents was highest for vinegared rice and fish (47%), followed by freezing (33%), canning (5%), and dried food (4%), in that order.

Synergistic effects of dietary supplementation of <i>Bacillus subtilis</i> WB60 and mannanoligosaccharide (MOS) on growth performance, immunity and disease resistance in Japanese eel, <i>Anguilla japonica</i>

Lee, Seunghan,Katya, Kumar,Hamidoghli, Ali,Hong, Jeongwhui,Kim, Dae-Jung,Bai, Sungchul C. Elsevier 2018 FISH AND SHELLFISH IMMUNOLOGY Vol.83 No.-

<P><B>Abstract</B></P> <P>This study evaluated the synergistic effects of dietary <I>Bacillus subtilis</I> WB60 and mannanoligosaccharide (MOS) in juvenile Japanese eel, <I>Anguilla japonica</I>. Seven treatment diets were formulated to contain three different levels of <I>B. subtilis</I> (0.0, 0.5, and 1.0 × 10<SUP>7</SUP> CFU/g diet denoted as BS<SUB>0</SUB>, BS<SUB>0.5</SUB>, and BS<SUB>1</SUB>, respectively) with two MOS levels (0 and 5 g/kg diet denoted as M<SUB>0</SUB> and M<SUB>5</SUB>, respectively), and one diet with oxytetracycline (OTC) at 5 g/kg diet. Each diet (BS<SUB>0</SUB>M<SUB>0</SUB> (CON), BS<SUB>0</SUB>M<SUB>5</SUB>, BS<SUB>0.5</SUB>M<SUB>0,</SUB> BS<SUB>0.5</SUB>M<SUB>5,</SUB> BS<SUB>1</SUB>M<SUB>0,</SUB> BS<SUB>1</SUB>M<SUB>5</SUB>, and OTC) was fed to triplicate groups of 20 fish averaging 9.00 ± 0.11 g (mean ± SD) for eight weeks. Average weight gain, feed efficiency, specific growth rate and protein efficiency ratio of fish fed the BS<SUB>0.5</SUB>M<SUB>5</SUB> and BS<SUB>1</SUB>M<SUB>5</SUB> diets were significantly higher than those of fish fed CON, BS<SUB>0.5</SUB>M<SUB>0</SUB> and OTC diets (<I>P</I> < 0.05). Significant increases in the nonspecific enzymatic activities (e.g., lysozyme and myeloperoxidase) were detected from fish fed the BS<SUB>0.5</SUB>M<SUB>5</SUB>, BS<SUB>1</SUB>M<SUB>5</SUB>, and OTC diets compared to the CON, BS<SUB>0.5</SUB>M<SUB>0</SUB>, and BS<SUB>0</SUB>M<SUB>5</SUB> diets (<I>P</I> < 0.05). Whereas, immunoglobulin M expressions were recorded significantly higher for fish fed the BS<SUB>0.5</SUB>M<SUB>5</SUB> and BS<SUB>1</SUB>M<SUB>5</SUB> diets compared to those of fish fed the other diets (<I>P</I> < 0.05). Also, heat shock protein 70 mRNA levels of fish fed BS<SUB>0.5</SUB>M<SUB>5</SUB> and BS<SUB>1</SUB>M<SUB>5</SUB> diets were significantly higher than those of fish fed the CON diet (<I>P</I> < 0.05). Histological observations of the intestinal morphology showed healthier gut for fish fed BS<SUB>0.5</SUB>M<SUB>5</SUB> and BS<SUB>1</SUB>M<SUB>5</SUB> diets than those fed CON, BS<SUB>0</SUB>M<SUB>5</SUB>, and OTC diets. Additionally, resistance to bacterial challenge with <I>Vibrio anguillarum</I> was recorded significantly lower for fish fed the CON diet than those fed other diets (<I>P</I> > 0.05). Therefore, the results for growth performance, non-specific immune responses, intestinal morphology, and disease resistance demonstrated that supplementation of <I>B. subtilis</I> at 0.5 × 10<SUP>7</SUP> CFU/g diet and mannanoligosaccharide at 5 g/kg diet could have beneficial synergistic effects in Japanese eel. The isolated probiotic from eel and the selected prebiotic could lead to the development of a specific and potential synbiotic in Japanese eel aquaculture.</P> <P><B>Highlights</B></P> <P> <UL> <LI> •Higher growth and immunity could be achieved by the administration of <I>Busilus subitlis</I> and mannanoligosaccharide. </LI> <LI> •Dietary synbiotic could have more benefits than probiotic and prebiotic alone. </LI> <LI> •Specific synbiotic has the potential to replace chemical antibiotics in Japanese eel aquaculture. </LI> </UL> </P>

탐진강 ‘장어다물’ 어로와 생태

박종오 국립무형유산원 2022 무형유산 Vol.- No.12

Gangjinman is a bay located at the mouth of Tamjingang, the largest river in Gangjin-gun, Jeollanam-do. Tamjingang maintains brackish water because it is in contact with seawater. Gangjinman has an environment suitable for living things. Therefore, various kinds of fish live there. Here, we use jang-eo darmul to catch baemjang-eo(Japanese eel). Jang-eo damul is made by stacking stones in the form of a cone about on meter high in a place where the tide is not urgent and the floor is hard. Jang-eo damul is a method of catching fish using the eels' habit. Eels usually hide themselves in stone cracks or tidal flats during the day. They have a habit of feeding at night. The jang-eo darmul method is to stack a pile of stones, induce eels to hide, and then catch eels hiding here. Eel fishing here starts in June and runs until early September. It is mainly done when the water is drained during the day. Jang-eo damul is applied with a fishing method suitable for the ecological environment. The fishing period is tailored to eel ecology, and experience is added to determine the fishing period. Tide time according to working time conditions is used according to the fishing environment. Nets were introduced into fishing in line with changes in tools. There are various networks connected to jang-eo darmul fishing. These are the Fishing Party Network and the Sales Network. The Fishing Party Network refers to the relationship among fishermen who perform jang-eo darmul. The Sales Network refers to the relationship between fishermen and sellers related to the sale of caught eels. The degree of relationship varies depending on the sales relationship of the eel caught. The relationship between fishermen and fishermen is somewhat looser compared to the relationship between fishermen and sellers. Ecological folklore is the work of grasping people and the environment, adaptation between people and people, and relationships within it. In other words, it refers to a culture created through the establishment of interrelationships between people who adapt to the natural environment and humanities environment. Jang-eo darmul is a valuable cultural resource created by the combination of Gangjinman's ecological environment and the wisdom of those who were adapting to it. 전라남도 강진군의 최대 하천인 탐진강 하구에 자리하고 있는 강진만은 바닷물과의 소통을 통해 여전히 기수역을 유지하고 있는 곳이다. 생물 서식에 적합한 환경을 가지고 있어 다양한 종류의 어류가 서식하고 있다. 이곳에는 ‘장어다물’을 이용하여 ‘뱀장어’잡이가 이루어지고 있다. ‘장어다물’은 조류가 급하지 않고 바닥이 단단한 곳에 약 1m 정도 높이의 고깔 형태로 돌을 쌓아 올려 만든 것이다. ‘장어다물’은 뱀장어의 습성을 이용한 함정 어구의 일종이다. 뱀장어는 보통 낮에는 돌 틈이나 갯벌에 몸을 숨기고 있다가 밤이 되면 먹이활동을 하는 습성을 지닌다. 이러한 장어의 습성을 이용해 돌무더기를 쌓아 두고 장어가 들어가 숨도록 유인한 후 이곳에 숨어 지내는 장어를 잡는 것이 ‘장어다물’ 어로 방식이다. 장어다물 어로에는 생태 환경에 맞는 방식이 적용되고 있다. 어로 작업 시기는 뱀장어 생태에 맞춰 이루어지는데, 경험이 더해져 결정된다. 작업 시간 여건에 맞은 물때를 이용하고 있으며, 도구의 변화에 맞춰 그물을 어로 작업에 도입하였다. 이곳에서의 장어잡이는 6월부터 시작하여 9월 초까지 진행되는데, 한낮에 물이 빠지는 때에 주로 행한다. ‘장어다물’ 어로를 유지하기 위해서는 다양한 관계망이 작동하는데, ‘어로 당사자 관계망’과 ‘판매 관계망’이 가장 중요하다. 어로 당사자 관계망은 ‘장어다물’을 행하는 어민들 상호 간의 관계를 의미하며, 판매 관계망은 어획된 뱀장어의 판매와 관련된 어민과 판매자와의 관계를 말한다. 어획된 뱀장어의 판매에 대한 관련성의 밀접 정도에 따라 어민과 어민 사이는 어민과 판매자와의 관계에 비해 다소 느슨한 관계망이 형성된다. 생태 민속은 사람과 환경, 사람과 사람 간의 적응과 그 안에서 이루어지는 관계에 관해 파악하는 작업이다. 즉, “자연환경 및 인문 환경에 적응하는 사람들의 상호관계 맺음을 통해 만든 문화”를 말한다. ‘장어다물’은 강진만의 생태 환경과 이것에 적응하던 사람들의 지혜가 오롯이 합쳐져서 만들어진 소중한 문화 자원이다.

Korean Mistletoe Viscum album coloratum Induces Specific and Non-Specific Immune Responses in Japanese Eel Anguilla japonica

최상훈,노진구,최민순,박성우,박관하,윤종만,박경일 한국양식학회 2009 韓國養殖學會誌 Vol.22 No.1

Effects of Korean mistletoe extracts (KM-110), Viscum album coloratum on the specific and non-specific immune responses of Japanese eel Anguilla japonica were examined. The optimal concentration not showing toxicity of KM-110 was determined to 30-40 μg/ml in vitro and 100 μg/100 g of fish in vivo. Even 1000 μg of KM- 110/100 g of fish did not show any clinical problem in fish though the levels of toxic parameters were slightly increased. In terms of antibody production, KM-110 significantly elicited more antibody production than FCA or β-glucan. β-glucan plus KM-110 group synergistically enhanced antibody production. There was no significant difference between KM-110 and KM-110 plus β-glucan group. The ROI production by head kidney (HK) leucocytes of eel injected with 500 or 1000 μg KM-110 was significantly (P<0.05) enhanced than the control and FCA-treated group. Maximum increase in the NBT reduction value was observed in 1000 μg KM-110 group but no significant difference was found between 500 and 1000 μg KM group. The level of serum lysozyme activity was significantly (P<0.05) higher in the 500 and 1000 μg KM-110- or FCA-treated group than in the control and 200 μg KM-110 group. The phagocytic activities of HK leucocytes isolated from eel injected with 500 and 1000 μg KM-110 were significantly (P<0.05) higher than 200 μg KM-110 and PBS-injected control group. Korean mistletoe appeared to be a good activator of the specific and non-specific immune responses of Japanese eel.

Comparative evaluation of dietary probiotics <i>Bacillus subtilis</i> WB60 and <i>Lactobacillus plantarum</i> KCTC3928 on the growth performance, immunological parameters, gut morphology and disease resistance in Japanese eel, <i>Anguilla japonica</i>

Lee, Seunghan,Katya, Kumar,Park, Youngjin,Won, Seonghun,Seong, Minji,hamidoghli, Ali,Bai, Sungchul C. Elsevier 2017 FISH AND SHELLFISH IMMUNOLOGY Vol.61 No.-

<P><B>Abstract</B></P> <P>The current experiment was conducted to evaluate and compare the efficacy of two different probiotics <I>Bacillus subtilis</I> WB60 and <I>Lactobacillus plantarum</I> KCTC3928 in diet of Japanese eel, <I>Anguilla japonica</I>. Seven experimental diets were formulated to contain no probiotics (CON), three graded levels of <I>B. subtilis</I> at 10<SUP>6</SUP> (BS<SUB>1</SUB>), 10<SUP>7</SUP> (BS<SUB>2</SUB>), 10<SUP>8</SUP> (BS<SUB>3</SUB>) and <I>L. plantarum</I> at 10<SUP>6</SUP> (LP<SUB>1</SUB>), 10<SUP>7</SUP> (LP<SUB>2</SUB>), 10<SUP>8</SUP> (LP<SUB>3</SUB>) CFU/g diet. Twenty fish averaging 8.29 ± 0.06 g were distributed in to 21 aquaria and were randomly assigned to one of the experimental diets in triplicate groups. Average weight gain (WG), feed efficiency (FE), and protein efficiency ratio (PER) of fish fed <I>B. subtilis</I> at 10<SUP>7</SUP> (BS<SUB>2</SUB>) and 10<SUP>8</SUP> (BS<SUB>3</SUB>) CFU/g diet were significantly higher than those of fish fed other experimental diets (<I>P</I> < 0.05). Nonspecific enzymatic activities including lysozyme, superoxide dismutase (SOD), myeloperoxidase (MPO) from fish fed <I>B. subtilis</I> at 10<SUP>7</SUP> (BS<SUB>2</SUB>) and 10<SUP>8</SUP> (BS<SUB>3</SUB>) CFU/g diet were detected to be significantly higher than that from fish fed CON diet (<I>P</I> < 0.05). Whereas, level of intestine glyceraldehyde-3-phosphate dehydrogenase (GAPDH), heat shock protein 70, 90 (HSP70, 90) and immunoglobulin (IgM) from fish fed <I>B. subtilis</I> at 10<SUP>7</SUP> and 10<SUP>8</SUP> CFU/g diet were recorded to be significantly higher than those of fish fed other experimental diets (<I>P</I> < 0.05). Parameters for intestinal morphology and histology suggested a healthier gut for the fish fed10<SUP>8</SUP> (BS<SUB>3</SUB>) CFU/g diet as compared to other treatment groups. Whereas, results from the disease challenge test with bacteria <I>Vibrio angulillarum</I> showed significantly lower survival rate for fish fed CON diet than those of fish fed other experimental diets. Therefore, these results indicated that oral supplement of <I>B. subtilis</I> at 10<SUP>8</SUP> (BS<SUB>3</SUB>) CFU/g diet could be a more effective source of probiotic compared to <I>L. plantarum</I> in Japanese eel.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Preliminary report comparing two probiotics, <I>Bacillus subtilis</I> WB60 and <I>Lactobacillus plantarum</I> KCTC3928. </LI> <LI> Differences on the growth performance, survival rate, immune parameters and gut morphology were clearly observed. </LI> <LI> Oral administration of bacteria spp. <I>B. subtilis</I> at 10<SUP>7</SUP> CFU/g kg<SUP>−</SUP> <SUP>1</SUP> diet could be a more promising source and dose compared to probiotic <I>L. plantarum</I> in freshwater aquaculture. </LI> </UL> </P>

뱀장어(Anguilla japonica)용 사료 기능성 첨가제로써의 발효 혈분 이용성 평가

김수혁,신재범,이연지,김원훈,문상욱,유행수,이경준 한국수산과학회 2023 한국수산과학회지 Vol.56 No.5

The effects of dietary supplementation with fermented blood meal (FBM) in two forms were evaluated on the growth performance, hematological parameters, innate immune response, antioxidant capacity, digestive enzyme activity and intestinal histology of Japanese eel Anguilla japonica. A commercial powder feed was used as a basal diet (Con). Six other diets were prepared by supplementing 2, 4 and 6% FBM either in powder or liquid form to the Con diet (designated as P2, P4, P6, L2, L4 and L6, respectively). In total 420 eels (initial mean body weight: 55.1±1.71 g) were distributed into 21 tanks (450L) at a density of 20 eels per tank. Three replicate groups of fish were fed one of the seven diets twice daily for 12 weeks. No significant differences were observed in the growth performance and survival among all groups. Fish fed FBM-containing diets showed significantly improved hematological parameters, innate immunity and antioxidant capacity than those in the Con group. Fish fed FBM-containing diets showed significantly enhanced digestive enzyme activity, villus length and goblet cells than those in fish fed Con diet. These results indicate that both powder and liquid FBM could be a good functional feed additive to improve innate immunity and digestion in Japanese eel.

Heterologous Production and Glycosylation of Japanese Eel Follitropin Using Silkworm

홍선미,최지현,조선정,민관식,김대정,이재만,Takahiro Kusakabe 한국생물공학회 2019 Biotechnology and Bioprocess Engineering Vol.24 No.5

Follitropin, an important gonadotropin hormone, participates in vitellogenesis and spermatogenesis. Equine chorionic gonadotropin (eCG) can induce gonadotropin hormone activity in non-equid species and exhibits a long biological half-life. Here, we report the production, using silkworm larval and pupal systems, of biologically active recombinant hybrid-type follitropins based on the coding sequence of the eCG C-terminal peptide (CTP) between the mature β- and α-chains of eel. The three constructs, rJeFSH, rJeFSH·eCG, and rJeFSH·2xeCG were produced and verified to be N- or O-glycosylated and secreted mature peptides. Although rJeFSH·eCG contains more elaborate O-linked carbohydrate chains than rJeFSH, it elicited no significant in vitro oocyte maturation, which may be a result of insufficient terminal sialylation of its Nand O-linked carbohydrate chains. Then, a hybrid of rJeFSH·2xeCG extended with two eCG CTP. Furthermore, the receptor binding assay revealed potency of rJeFSH and rJeFSH·2xeCG to be a few folds greater than that of rJeFSH·eCG. The findings of this study will be useful for the development of more efficient GTHs in teleosts, including eels, when various modifications with two or more extended eCG CTP produced by silkworm are included.

Effects of Water Temperature Changes on the Oxygen Consumption Rhythm in the Japanese eel, Anguilla japonica

( Jong Wook Kim ),( Tae Won Lee ),( Il Noh ),( Wan Soo Kim ) 한국환경과학회 2011 한국환경과학회지 Vol.20 No.8

We investigated the effects of temperature changes on the oxygen consumption rhythm in Japanese eels, Anguilla japonica, using an automatic intermittent flow respirometer (AIFR). The endogenous rhythm of the oxygen consumption rate (OCR) in the eels (n = 18; 44-74 cm, 145-690 g), freshly collected by bag net from estuaries, was nearly synchronous with the tidal pattern of the estuarine collection site. The magnitude of mean OCR (mOCR) of eels showed variable range of 82.2 - 116.5 ml O2 kg-1 ww h-1 under constant conditions. In case of increasing temperature from 25 to 38℃, the OCR of eels exhibited a gradually increasing trend with a rhythmic pattern until 36℃. Above 36℃, the rhythms of the OCR dampened and the OCR decreased rapidly at around 36 - 37℃. The OCR of the eels exhibited the maximum value at 38℃, and then it sharply decreased. The results suggested that the critical thermal maximum (CTM) regarding the endogenous rhythms of the eels was at around 36 - 37℃ when water temperature increased at 0.5℃/14 h following the acclimation at 25℃. In case of decreasing temperature (0.5℃/14 h) from 25 to 0℃, the OCR of the eels displayed a abrupt decrease up to 23℃, and between at 23 and 20℃, there was an agitation which showed a slight increase in the OCR with a duration of 1-2 days. Below 9℃, the OCR rhythm of the eels showed a constant state regardless of temperature decreasing. These results suggest that the Japanese eel has an upper incipient lethal temperature at 36℃, with a lower thermal limit at 9℃. The biochemical aspects of the eels influenced by water temperature need to be further studied.