This study aims to analyze causalities among Hairtail prices by distribution channel using a vector autoregressive model. This study applies unit-root test for stability of data, uses Granger causality test to know interaction among Hairtail Prices by distribution channel, and employes the vector autoregressive model to estimate statistical impacts among t-2 period variables used in model. Analyzing results of this study are as follows. First, ADF, PP, and KPSS tests show that the change rate of Hairtail price by distribution channel differentiated by logarithm is stable. Second, a Granger causality test presents that the producer price of Hairtail leads the wholesale price and then the wholesale price leads the consumer price. Third, the vector autoregressive model suggests that the change rate of Hairtail producer price of t-2 period variables statistically, significantly impacts change rates of own, wholesale, and consumer prices at current period. Fourth, the impulse response analysis indicates that impulse responses of the structural shocks with a respectively distribution channel of the Hairtail prices are relatively more powerful in own distribution channel than in other distribution channels. Fifth, a forecast error variance decomposition of the Hairtail prices points out that the own price has relatively more powerful influence than other prices.

This paper is to investigate the effect of the immersion time in the traditional hairtail hand line for developing the fishing methods and the fishing gear in the coast of jeju. The operating of 32 times was made with each different immersion time of hairtail hand line, and the relations between the catch and the immersion time were examined. As the result, targeted species rate was over 98% of total catch. From about 800 seconds after casting, the hooking rate was decreased and the bite loss rate was increased, it seems to be made by the decreasing factors of predators including the cutting of branch lines etc. In addition, it was supposed that the hooking rate and the bait loss rate had a deep connection with feeding time zone. The level of the correlation coefficient of the bait loss rate according to the immersion time was 0.54 at p≤0.01, in the case of the hooking rate, 0.59 was chosen after about 800 seconds. The hooking rate and the bait loss rate according to the hook number were not irrelevant to the fish school layer. Additionally, it was assumed that the bait loss rate was related to the depth of water.

This experimental study was carried out to obtain the base data for saving the man power in the fishing operation of largehead hairtail hand line by using the continuous type hand line system with a rotary device which could make a main line move automatically. In order to solve the twists and entangling on the main line happened during operating test, the resistance board was suspended at the end of the main line at sea. As the result, there were no problems of tangling and so on due to up and down moving of a main line. According to the control of a fixed angle of guide roller, it was possible to prevent the main line to be separated from a side roller and a guide roller. In addition, PVC tube between a guide roller and a side roller enabled a main line to be moved smoothly without any entanglement.

1. 제주해협에서는 6월에 가장 낮은 생물량 분포를 나타내었고, 가을철(11월)에 가장 높은 생물량 분포를 보이면서 높은 2차 생산력을 보이는 것으로 사료된다. 2. 해황 및 습중량과의 관계에서 가장 높은 분포를 나타내는 정점은 각각 정점 14와 11로 그 출현위치는 해협의 중앙부분이고, 한국남해연안역 및 제주도 북부연안역에는 다소 낮은 생물량분포를 보이고 있으며, 생물량 분포가 높게 나타나는 해역의 특징은 patch의 형태로 분포하였다 반면 한국남해연안역에 비하여 제주도 북부연안역에높은 생물량 분포를 나타냄으로써 제주해협에서의 갈치어장 형성위치와 생물량 분포와의 관계가 밀접하게 나타날 것으로 판단된다. 그리고, 가을 의 해황 특성인 서로 다른 이질수괴의 경계역인 안상부 해황의 중심에 높은 생물량을 나타냈다. 3. 제주해협에서 patch의 형태로 생물량 분포가 높게 나타나는 해역의 외측에 좋은 갈치어장이 형성되었다.

The study on the Assembling Mechanism of the Hairtail, Trichiurus lenpturus, at the Fishing Grounds of the Cheju Strait had been investigated by analyzing the relationship of the oceanographic conditions and the fishing ground of the Hairtail in the Cheju Strait. 1. The fishing grounds of the hairtail at the Cheju Strait are formed at the bottom of a high temperature of the tidal front at the coast. area of northern Cheju Island, the tip of the linguiform is high in salinity at the eastern and western entrances of Cheju Island, low salinity eddy on the surface and its surrounding front, various water masses in the Strait and coastal waters of the South Sea in Korea. 2. The fishing grounds of the Hairtail at the Cheju Strait begins with the sea surface temperature higher than 15℃ and the incoming of low salinity water now from the East China Sea. 3. Estimation of optimum temperature and salinity per season based upon analysis for relationship between temperature of water and salinity of the bottom layer and the catch is : 15.2~16.4℃, 34.20~34.40‰ in spring(June); 14.4~ 17.0℃, 33.70~34.30‰ in summer(July~September); and 15.7~ 18.6℃, 33.70~34.50‰ in autumn(October~December). Hairtail are mostly caught at the Yellow Sea Warm Current and Tsushima Current with temperature over 14.5℃ and salinity over 33.70‰ at the bottom layers of the Cheju Strait. 4. Considering the relationship between the amount of hairtail catch and the water temperature of bottom layer, when the bottom water being above 14.0℃ flowed into Cheju Strait through the western entrance of the strait in summer, the ca-h appears to have been abundant. In contrast, the catch has been poor when the temperature of such water was recorded to be below 13℃ Therefore, distribution patterns of water at the bottom layer can be used as a forecast index whether the catch of a certain year will be good or poor.

In the present study, muscle tissues were obtained separately from individuals from Atlantic hairtail population (AHP), Gunsan hairtail population (GHP) and Chinese hairtail population (CHP), respectively. The seven decamer primers were used to generate the shared loci, specific, unique shared loci to each population and shared loci by the three hairtail populations. Here, averagely, a decamer primer generated 64.7 amplified products per primer in the AHP population, 55.7 in GHP population and 56.4 in CHP population. The number of unique shared loci to each population and number of shared loci by the three populations generated by genetic analysis using 7 decamer primers in AHP, GHP and CHP population. 119 unique shared loci to each population, with an average of 17 per primer, were observed in the AHP population, and 28 loci, with an average of 4 per primer, were observed in the CHP population. The hierarchical dendrogram point out three main branches: cluster 1 (ATLANTIC 01 ~ ATLANTIC 07), cluster 2 (GUNSAN 08 ~ GUNSAN 14) and cluster 3 (CHINESE 15 ~ CHINESE 21). The shortest genetic distance displaying significant molecular difference was between individuals' CHINESE no. 16 and CHINESE no. 18 (0.045). In the long run, individual no. 01 of the AHP population was most distantly related to CHINESE no. 19 (genetic distance = 0.430). Consequently, PCR analysis generated on the genetic data displayed that the geographic AHP population was widely separated from CHP population, while individuals of CHP population were fairly closely related to those of GHP population.

Hairtails (Trichiurus lepturus) are the most popular marine products in Korea because of their taste and nutritional value, and Koreans consume them in large quantities. Hairtail, ecologically important warm water fish species, belonging to family Trichiuridae, widely distributed on the coast of the West Sea, South Sea and Jeju Island in the Korean Peninsula and the several sea areas in China under the natural ecosystem. However, in spite of their economic and scientific consequences, a little information currently exist regarding the physiological and ecological levels only of hairtail species in Korea (Koo et al., 2004). Simply the biological fisheries feature, distribution and migration of hairtail (T. lepturus) in Korean waters were surveyed (Park et al., 2005). Currently, imported hairtail have been altered into endemic hairtail because of high edge. In the present study, to explicate the genetic distances and differences among geographical hairtail populations, we accomplished a clustering analysis of three hairtail populations collected from Atlantic, Korea and Chinese site. Muscle tissues were obtained separately from individuals from Atlantic hairtail population (AHP), Gunsan hairtail population (GHP) and Chinese hairtail population (CHP), respectively. The muscle was collected in sterile tubes, immediately placed on dry ice, and stored at －40℃ until the genomic DNA extraction. Genomic DNA was extracted and purified under the conditions described previously (Yoon and Kim, 2004). Seven primers (BION-02, BION-03, BION-04, BION-08, BION-09, BION-13 and BION-17) were shown to generate the shared loci, specific loci, unique shared loci to each population and shared loci by the three populations which could be obviously scored. The degree of variability was calculated by use of the Dice coefficient (F), which is given by the formula: F = 2 nab / (na+nb), where nab is the number of bands shared between the samples a and b, na is the total number of bands for sample a and nb is the total number of bands for sample b (Jeffreys and Morton, 1987; Yoke-Kqueen and Radu, 2006). Euclidean genetic distances within- and between-population were also calculated by complete linkage method with the support of the hierarchical dendrogram program Systat version 13 (SPSS Inc., Chicago, IL, USA). Here, the seven decamer primers BION-02, BION-03, BION-04, BION-08, BION-09, BION-13 and BION-17 were used to generate the shared loci, specific, unique shared loci to each population and shared loci by the three populations. In the present study, averagely, a decamer primer generated 64.7 amplified products per primer in the AHP population, 55.7 in GHP population and 56.4 in CHP population. The number of unique shared loci to each population and number of shared loci by the four populations generated by genetic analysis using 7 decamer primers in AHP, GHP and CHP population. 119 unique shared loci to each population, with an average of 17 per primer, were observed in the AHP population, and 28 loci, with an average of 4 per primer, were observed in the CHP population. Many researchers studied the sizes of DNA fragments in the PCR profiles of five species of Eastern Pacific abalone (genus Haliotis) (Muchmore et al., 1998), black tiger shrimp (Penaeus monodon) (Tassanakajon et al., 1998), shrimp populations (Yoon and Kim, 2003) and deep sea lobster (Puerulus sewelli) (Park et al., 2005). The hierarchical dendrogram point out three main branches: cluster 1 (ATLANTIC 01 ~ ATLANTIC 07), cluster 2 (GUNSAN 08 ~ GUNSAN 14) and cluster 3 (CHINESE 15 ~ CHINESE 21). The shortest genetic distance displaying significant molecular difference was between individuals’ CHINESE no. 16 and CHINESE no. 18 (0.045). In the long run, individual no. 01 of the AHP population was most distantly related to CHINESE no. 19 (genetic distance = 0.430). The genetic distance between the Indian Ocean lobster and the Korean Slipper lobster species ranged between 0.040 and 0.612 (Park et al., 2005). Consequently, PCR analysis generated on the genetic data displayed that the geographic AHP population was widely separated from CHP population. From what has been said above, the potential of genetic analysis to identify diagnostic markers for the identification of three hairtail populations has been demonstrated. Generally speaking, using a variety of arbitrary primers, PCR has been applied to identify polymorphic/specific markers particular to line, species and geographical population, as well as genetic diversity/polymorphism in diverse species of organisms (McCormack et al. 2000; Yoon and Kim 2004).

PCR analysis generated on the genetic data showed that the geographic hairtail (Trichiurus lepturus) population from Korea in the Yellow Sea was more or less separated from geographic hairtail population from China in the South Sea. The average bandsharing value (mean±SD) within hairtail population from Korea showed 0.859±0.031, whereas 0.752±0.039 within population from China. Also, bandsharing values between two hairtail populations ranged from 0.470 to 0.611, with an average of 0.542±0.059. As compared separately, the bandsharing values of individuals within hairtail population from Korea were comparatively higher than those of individuals within population from China. The hierarchical dendrogram resulted from reliable oligonucleotides primers, indicating two genetic clusters composed of cluster 1 (KOREANHAIR1~KOREANHAIR11) and cluster 2 (CHINESEHAI12~CHINESEHAI22). The genetic distances between two geographic populations ranged from 0.038 to 0.476. Individual No. 11 within hairtail population from Korea was genetically closely related with No. 10 (genetic distance=0.038). The longest genetic distance (0.476) displaying significant molecular difference was also between individual No. 01 within hairtail population from Korea and No. 22 from Chinese. In the present study, PCR analysis has revealed significant genetic distances between two hairtail population pairs (P<0.05).

Hairtail, Trichiurus lepturus, ecologically warm water fish species, belonging to family Trichiuridae, widely distributed on the coast of the West Sea, South Sea and Jeju island in the Korean Peninsula and the several sea areas in China under the natural ecosystem. The food consumption of this species has increased considerably in various types of restaurants (including restaurants specializing in serving hairtails roasted and soy-sauce glazed cutlass fish with radish or other vegetables) for a long time. However, in spite of their economic and scientific consequences, a little information currently exist regarding the physiological and ecological levels only of hairtail species in Korea. Only the biological fisheries feature, distribution and migration of hairtail, Trichiurus lepturus, in Korean waters were in vestigated (Kimatal, 1998; Parketal, 2002). Lately, imported hairtail have been changed into endemic hairtail because of high margin. In the present study, to elucidate the genetic distances and differences among geographical hairtail, Trichiurus lepturus, populations, we performed a clustering analysis of two hairtail populations collected from Korea and China. Muscle tissues were collected separately from hairtail, Trichiurus lepturus, in dividuals from Korea in the Yellow Sea and China in the East Sea, respectively. RAPD-PCR analysis was performed on DNA samples extracted from a total of 44 (specimen numbers for duplicate experiments) individuals using eight arbitrarily selected primers of two decades of different decamer primers. Hairtail muscle was collected in sterile tubes, immediately placed on dry ice, and stored at －40℃ until the genomic DNA extraction. Genomic DNA was extracted and purified under the conditions described previously (Yoon and Kim, 2004). The degree of variability was calculated by use of the Dice coefficient (F), which is given by the formula: F = 2 nab/(na+nb), where nab is the number of bands shared between the samples a and b, na is the total number of bands for sample a and nb is the total number of bands for sample b (Jeffreys and Morton, 1987; Yoke-Kqueen and Radu, 2006). Euclidean genetic distances within- and between-populations were also calculated using the hierarchical dendrogram program Systat ver.10 (SPSS Inc., Chicago, IL, USA). The random primers OPA-07, OPA-20, OPB-14, OPB-15, OPB-17, OPB-18, OPD-16 and URP-07 showed common, polymorphic and specific bands produced using each primer to amplify genomic DNA isolated from the muscle of individuals. Accordingly, PCR analysis generated on the RAPD data showed that the geographic hairtail population from Korea in the West Sea was more or less separated from geographic hairtail population from China in the South Sea. The hierarchical dendrogram resulted from reliable four primers, indicating three genetic clusters composed of group 1 (Korean No. 1～11) and group 2 (Chinese No. 12～22). The genetic distances between two geographic populations ranged from 0.038 to 0.476. Individual No. 09 within hairtail population from Korea was genetically closely related with No. 06 (genetic distance = 0.104). The longest genetic distance (0.476) displaying significant molecular difference was also between individual No. 01 within hairtail population from Korea and No. 22 from Chinese. In the present study, RAPD-PCR analysis has revealed significant genetic distances between two hairtail population pairs. High levels of genetic polymorphisms and the existence of population differentiation between two hairtail populations showed RAPD-PCR approach is one of the suitable tools for individuals and/or population biological DNA studies.