• Korean Journal of Ichthyology
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• v.22 no.4
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• pp.217-224
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• 2010

An investigation was carried out to obtain basic information needed to develop methods for artificial propagation and conservation of the mottled skate Raja pulchra, an important food resource in western Korea that has declined from overfishing. In this paper we provide evidence of multiple spawning and describe properties of the ovary, and morphology of the egg capsule and the fully-formed offspring. The vitellogenic follicles in the ovary was $179.8{\pm}57.1$ (54~247) and can be classified into five size groups, which the last group of ova are considered as the moving to the capsule gland where fertilization and encapsulation of ova take place. The morphology of the egg capsule of R. pulchra is unique among the species of the family Rajidae and showed multi-embryo characteristics, having two to six yolks in each capsule. The adaptive morphological changes of larvae developing inside the egg capsule are described based on specimens extracted from the capsule.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.60 no.1
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• pp.57-70
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• 2024

In order to present a predictive drift model, Jeju National University's training ship was tested for about 11 hours and 40 minutes, and 81 samples that selected one of the entire samples at ten-minute intervals were subjected to regression analysis after verifying outliers and influence points. In the outlier and influence point analysis, although there is a part where the wind direction exceeds 1 in the DFBETAS (difference in Betas) value, the CV (cumulative variable) value is 6%, close to 1. Therefore, it was judged that there would be no problem in conducting multiple regression analyses on samples. The standard regression coefficient showed how much current and wind affect the dependent variable. It showed that current speed and direction were the most important variables for drift speed and direction, with values of 47.1% and 58.1%, respectively. The analysis showed that the statistical values indicated the fit of the model at the significance level of 0.05 for multiple regression analysis. The multiple correlation coefficients indicating the degree of influence on the dependent variable were 83.2% and 89.0%, respectively. The determination of coefficients were 69.3% and 79.3%, and the adjusted determination of coefficients were 67.6% and 78.3%, respectively. In this study, a more quantitative prediction model will be presented because it is performed after identifying outliers and influence points of sample data before multiple regression analysis. Therefore, many studies will be active in the future by combining them.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.5
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• pp.1407-1416
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• 2016

This study was conducted to investigated the effects of stocking density on growth and survival of sea cucumber, Apostichopus japonicus in the indoor multiple tank for 12 weeks. There were six treatments(stocking densities) in this experiment, i.e. 1, 2, 3, 4, 5 and 10 individuals per 10 L plastic aquarium($W41{\times}H24{\times}D11cm$, represented as D1, D2, D3, D4, D5 and D10, respectively). Each treatment had ten replicates. The results showed growth variation of sea cucumber, Apostichopus japonicus decreased with the increase of stocking densities. After the end of the experiment, no significant differences(P>0.05) between D1~D5 treatment group whereas significant differences(P<0.05) between D1 and D10 treatment group. Survival rate showed D1~D10 were 90%, 90%, 100%, 95%, 94% and 72%, respectively. Especially, significant differences(P>0.05) between D1~D5 and D10 treatment group. The results indicated optimum of stocking density for sea cucumber, Apostichopus japonicus within five individuals per 10 L plastic aquarium($0.05individuals/m^2$).

• Journal of Practical Agriculture & Fisheries Research
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• v.23 no.1
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• pp.81-87
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• 2021

Olive flounders which were cultured in commercial fish farm showed abnormal swimming behavior in November 2020. Then, gradual mortality was observed in the fish farm. During the diagnosis, bacterial strain KNCFKW-PN1 was isolated from the kidney of the dead fish. Based on the sequence of gyrase B subunit gene, KNCFKW-PN1 was proved to be Pseudoalteromonas nigrifaciens, showing 99.59% nucleotide identity with that of P. nigrifaciens LMG 2227^T. According to the result of antibiotic susceptibility test, P. nigrifaciens KNCFKW-PN1 showed intermediate resistance to ciprofloxacin, and was resistant to ampicillin, cefepime, cefotaxime, ceftazidime, and amikacin. This is the first report of the isolation of multiple-antibiotic-resistant P. nigrifaciens from olive flounder.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.3
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• pp.133-140
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• 2007

In 2006, we studied herbivore consumption rate and preference for algal species using laboratory experiments. In the no-choice feeding experiment, three herbivores (two sea urchins, Stronglyocentrotus nudus and Stronglyocentrotus intermedius and an abalone, Haliotis discus hannai) showed significantly (P<0.05) distinct preferences for four algae (Laminaria japonica, Undaria pinnatifida, Costaria costata and Ecklonia stolonifera). The alga preferred by S. nudus was L. japonica followed by U. pinnatifida, C. costata and E. stolonifera with respective daily feeding rates of $5.7{\pm}:0.85\;g,\;4.4{\pm}0.89\;g,\;3.1{\pm}0.39\;g\;and\;2.1{\pm}0.32\;g(mean{\pm}SE)$. A similar trend was found for S. intermedius. Interestingly, the herbivore consumption rates for the algae differed with or without competition. The competition stimulated the feeding activity for S. nudus, but lowered the activity for S. intermedius. The multi-choice feeding experiment confirmed that L. japonica was significantly preferred by two herbivores: S. nudus and H. discus hannai (Duncan's multiple range test, ANOVA, p<0.05).

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.6
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• pp.794-799
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• 2012

The cytochrome P450c17-I (CYP17-I) is one of the enzymes critical to gonadal development and the synthesis of androgens. Two single nucleotide polymorphisms (SNPs) were detected within the coding region of the CYP17-I gene in a population of 75 male Japanese flounder (Paralichthys olivaceus). They were SNP1 (c.C445T) located in exon2 and SNP2 (c.T980C (p.Phe307Leu)) located in exon5. Four physiological indices, which were serum testosterone (T), serum $17{\beta}$-estradiol ($E_2$), Hepatosomatic index (HSI), and Gonadosomatic index (GSI), were studied to examine the effect of the two SNPs on the reproductive endocrines of Japanese flounder. Multiple comparisons revealed that CT genotype of SNP1 had a much lower T level than CC genotype (p<0.05) and the GSI of individuals with CC genotype of SNP2 was higher than those with TT genotype (p<0.05). Four diplotypes were constructed based on the two SNPs and the diplotype D3 had a significantly lower T level and GSI. In conclusion, the two SNPs were significantly associated with reproductive traits of Japanese flounder.

• The Journal of Fisheries Business Administration
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• v.49 no.4
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• pp.37-52
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• 2018

Busan is a representative of ocean cities in South Korea, which attracts many Chinese tourists. As a number of Chinese tourists increase, Chinese tourists' evaluations of sightseeing resources in Busan appear extremely important. However, there are few researches on Chinese tourists' evaluations of sightseeing in Busan. The purpose of this paper is to analyze Chinese tourists' evaluations of Busan tourism. Chinese tourists who travel to Busan are chosen as research objects and several aspects including marine, fisheries and general tourism are investigated to evaluate the tourists' overall satisfaction of the tourism in Busan. IPA analysis, factor analysis multiple regression analysis are used for the research. The results are as follows. Chinese tourists' evaluations of the importance and performance level of variables on Busan tourism were significantly different (total 19 of 25 variables) and the performance was lower than importance. This means the outputs of the various Busan tourism elements do not live up to their expectations. The findings show that Chinese visitors have high satisfaction on infrastructures of fisheries tourism (e.g. cleanness of aquatic product tourism facilities and sanitary state on fishery products), but low satisfaction in terms of the contents (e.g. unique cooking method experience of seafood and traditional seafood cooking consumption). The factors of fisheries tourism (e.g. product services of fisheries tourism and the attractiveness of seafood in Busan) never affect their satisfaction and intention to revisit and recommend the city.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.3
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• pp.181-189
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• 2002

This paper describes the positioning accuracies for single and multiple reference stations at fixed stations in Yosu harbor and Pukyong National University in the south coast of Korea from Jan. to Oct. 2001. Also we observed the change of positioning accuracy during a day and the available range of the DGPS reference station. he results obtained are main summarized as follows; 1. With single DGPS reference station, 2drms and the average positioning .error were 5.6m, 7.3m respectively. Measurement positions indicated an incline toward one way away from the actual position. 2. With multiple DGPS reference stations, 2drms and the average position error were 5.5m, 3.2m for the arithmetic mean, respectively. They were 5.3m, 3.8m for the weighted average, respectively. As far as the separation between the user and the reference station, using multiple reference stations improved position accuracy more than using single reference station. 3. The average positioning error increased between 16: 00 and 22 : 00. The average number of observed satellite and HDOP were 7.1m, 0.49 respectively. 4. Coverage of DGPS reference stations in the south coast of Korea was estimated to be 110nm. Signal strength and signal to noise ratio was not available the DGPS signal below 19㏈, 8㏈ respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.6
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• pp.365-371
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• 2005

The antimicrobial resistance patterns to the 10 antimicrobial agents of potential pathogenic vibrios isolated from seawater and a variety of farmed fishes, including oliver flounder (Payalichthys olivaceus), black rock fish (Sebastes schlegeli), red sea bream (Pagyus major) and sea bass (Lateolabyax japonicus), were investigated from May to October, 2004. A total of 314 strains of the genus vibrios were isolated from 126 collected samples, and the number of isolated strains of Vibrio payahaemolyticus and Vibrio alginolyticus were 194 and 120, respectively. Apparently $98.5\%$ of V. parahaemolyticus and $100\%$ of V. alginolyticus isolates demonstrated antimicrobial resistance against at least one antimicrobial agent. The resistance of V. parahaernolyticus isolates to ampicillin ($97.9\%$) was highest, followed by oxolinic acid ($26.8\%$), amikacin ($19.1\%$) and tetracycline and amoxicillin/clavulanic acid ($6.7\%$). V. alginolyticus isolates were resistant to ampicillin ($100\%$), solfamethoxazoleit,imethopenem ($25\%$), amikacln ($21.7\%$), amoxicillin/clavulanic acid ($15.8\%$), ciprofloxacin ($13.3\%$), and tetracycline and doxycycline ($11.7\%$). The rate of multiple antimicrobial resistance to at least four antimicrobials was higher in the V. alginolyticus isolates ($20.8\%$) than in the V. parahaemolyticus ($6.7\%$).

• The Journal of Fisheries Business Administration
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• v.35 no.2
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• pp.1-29
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• 2004

This paper aims to understand the points which the Board of Directors of the National Federation of Fisheries Cooperatives System has proposed, and to find some improvement. This Fisheries Cooperatives previously had a single board system operating two small board rooms which became independent within the two sectors of credit and .provision in addition to the existing board of directors. This is a very unique board of directors system which is not found in cooperatives in our country nor in the business world. This change of the board of directors of the Fisheries Cooperatives is ascribed to the reorganization of the system into a completely independent division system, which operates business separately based on each sector as opposed to the previous multiple cooperatives system. However, a plural board of directors system does contribute to the improvement of managerial efficiency by strengthening the self-control of each independent business section, but deepens conflicts between its internal organizations, and brings about a reverse function which might deteriorate both the controlling power of a systematic organization and the coordinating power between sectors. This paper made an analysis of acceptors' attitudes toward the board of directors of the fisheries cooperatives system by regulating all the staff directly related to the operation of the board of directors of the fisheries cooperatives system as a group of acceptors and by selecting one hundred and fifty persons among the staff as a sample. The inquiry into acceptors' attitudes was made using questionaries, and the data for this investigation was processed and analyzed using a statistical method. The contents of this paper are composed of I. an introduction, II. the findings of the questionary investigation, III. the overall opinion for the improvement of the board of directors system, and IV. a summary and conclusion.