We used nine decamer primers to generate DNA fragment sizes ranging from 100 bp to 1,600 bp from two bullhead (Pseudobagrus fulvidraco) populations of Dangjin in Korea. 376 fragments were identified in the cultured bullhead population, and 454 in the population of wild bullhead from Dangjin: 287 specific fragments (76.3%) in the cultured bullhead population and 207 (45.6%) in the wild bullhead population. On average, a decamer primer was used to generate 34.2 amplified products in a cultured bullhead. A RAPD primer was used to generate an average of 3.1 amplified bands per sample, ranging between 2.5 and 6.0 fragments in this population. Nine primers also generated 24 polymorphic fragments (24/376 fragment, 6.4%) in the cultured bullhead population, and 24 (24/454 fragments, 5.2%) in the wild bullhead population. The OPA-16 primer, notably, produced which 11 out of 11 bands (100%) were monomorphic in the wild bullhead population. 110 intra-population-specific fragments, with an average of 12.2 per primer, were observed in the cultured bullhead population. 99 fragments, with an average of 11.0 per primer, were identified in the wild bullhead. Especially, 55 inter-population-common fragments, with an average of 6.1 per primer, were observed in the two bullhead populations. The bandsharing value (BS value) of individuals within the wild bullhead population was substantially higher than was determined in the cultured bullhead population. The average bandsharing value was 0.596±0.010 within the cultured bullhead population,. and 0.657±0.010 within the wild bullhead population. The dendrogram obtained with the nine primers indicates two genetic clusters, designated cluster 1(CULTURED 01~CULTURED 11), and cluster 2(WILD 12~WILD 22). Ultimately, the longest genetic distance displaying significant molecular differences was determined to exist between individuals in the two bullhead populations, namely between individuals WILD no. 19 of the wild bullhead population and CULTURED no. 03 of the cultured bullhead population (genetic distance = 0.714). RAPD-PCR allowed us to detect the existence of population discrimination and genetic variation in Korean population of bullhead. This finding indicates that this method constitutes a suitable tool for DNA comparison, both within and between individuals, populations, species, and genera.

The author carried out PCR-based genetic platform to investigate the hierarchical polar dendrogram of Euclidean genetic distances of one bastard halibut population, particularly for Paralichthys olivaceus, which was further connected with those of the other fish population, by involving with the precisely designed oligonucleotide primer sets. Eight oligonucleotides primers were used generating excessively alterating fragments, ranging in size of DNA bands from larger than approximately 100 bp to less than 2,000 bp. As regards average bandsharing value (BS) results, individuals from Hampyeong population (0.810) displayed lower bandsharing values than did individuals from Wando population (0.877). The genetic distance between individuals approved the existence of close relationship in the cluster II. Relatively, individuals of one bastard halibut population were fairly related to that of the other fish population, as shown in the polar hierarchical dendrogram of Euclidean genetic distances. The points of a noteworthy genetic distance between two P. olivaceus populations demonstrated this PCR procedure is one of the quite a few means for individuals and/or populations biological DNA investigates, for species security and proliferation of bastard halibut individuals in coastal region of the Korea.

The author undertook PCR-founded genetic platform to investigate the hierarchical dendrogram of Euclidean genetic distances of one razor clam population, particularly for Solen corneus, which was further associated with those of the other clam population, by engaging with the precisely designed oligonucleotide primer sets. Seven oligonucleotides primers were used producing a total of 639 counted bands in population A and 595 in population B, respectively, ranging in size of DNA fragments from larger than approximately 50 bp to less than 1,100 bp. Their primers generated 39 specific fragments (6.10%) in population A and 47 (7.90%) in population B, respectively Comparatively, individuals of one razor clam population were fairly related to that of the other clam population, as shown in the hierarchical dendrogram of Euclidean genetic distances. The analysis of genetic variation between razor clam populations could offer important statistics for fisheries and mariculture. Generally the results showed specific and/or conserved genetic loci between razor clam populations. Specific markers established by the author will be valuable for the genetic analysis, species protection and increase of razor clam individuals in coastal region of the Korean Peninsula.

The author performed PCR-based genetic platform to measure the hierarchical dendrogram of Euclidean genetic distances of Korean scallop populations (KSP), particularly for Chlamys farreri, which was further compared with those of the Chinese scallop populations (CSP), by employing the with specifically designed oligonucleotide primer sets. The scallop is economically and ecologically very important bivalves in South Korea. Relatively, individuals of KSP population were fairly distantly related to that of CSP population, as shown in the hierarchical dendrogram of Euclidean genetic distances. Comparatively, individuals of KSP population were fairly distantly related to that of CSP population. Thus analysis of genetic difference between scallop populations could provide important statistics for fishery and aquaculture. Overall the results showed specific and/or conserved genetic loci between scallop populations. Information on the genetic distance of the bivalve would be helpful to understand scallop expansion or conservation in the coastal regions of South Korea. Specific markers developed by the author will be useful for the analysis of scallop population genetics and distribution in coastal region.

The PCR analysis was performed on DNA samples extracted from a total of 20 individuals using six oligonucleotides primers. The author accomplished clustering analyses to reveal the Euclidean genetic distances among four clam populations from Gochang, Seocheon, Taean and Anmyeon of the Korean peninsula. The oligonucleotides primer OPA-08 generated 5 unique loci to each population, approximately 550 bp and 600 bp, respectively, in the MCS population. Especially, the primer OPA-20 generated 15 unique loci to each population, which were identifying each population, approximately 400 bp, 750 bp and 800 bp, in the MCT population. Individuals from MCG clam population (0.637±0.227) exhibited higher bandsharing values than did individuals from MCG clam population (0.402±0.115) (P<0.05). The dendrogram obtained by the six oligonucleotides primers indicates four genetic clusters: cluster 1 (MCG 01, 02, 04 and 05), cluster 2 (MCS 06, 07, 08, 09 and 10), cluster 3 (MCT 11, 12, 13, 14 and 15) and cluster 4 (MCA 16, 17, 18, 19, 20 and MCG 03). Among the twenty clam individuals, the shortest genetic distance that displayed significant molecular differences was between individuals 14 and 15 from the MCT population (genetic distance = 0.094), while the longest genetic distance among the twenty individuals that displayed significant molecular differences was between individuals MCG no. 01 and MCG no. 02 (genetic distance = 0.687). Comparatively, individuals of MCS clam population were fairly closely related to that of MCT clam population, as shown in the hierarchical dendrogram of Euclidean genetic distances.

The author has investigated four Manila clam populations of the family Veneridae, belonging to the order Veneroida. The clam is also indigenous to some parts of the sandy regions of the West Sea in the Korean Peninsula, as well as in several areas in China. Clams are the most popular marine products in Korea because of their taste and nutritional value, and Koreans consume them in large quantities. However, in spite of their economic and scientific consequences, a little information currently exist regarding the physiological and ecological levels only of clam species in Korea. This study attempt is to elucidate the genetic distances within and between clam populations from the West Sea. Four populations of Manila clam (R. philippinarum) were obtained in adjacent district to the West Sea in Korea. Four populations of clam muscle was collected in sterile tubes, placed on ice immediately, and stored under refrigeration until needed. 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-species were also calculated by complete linkage method with the support of the hierarchical dendrogram program Systat version 10. The genomic DNA isolated from four Manila clams populations in the West Sea, were amplified several times by PCR reaction. The dendrogram obtained by the six oligonucleotides primers indicates three genetic clusters. The hierarchical dendrogram indicates four main branches: cluster 1 (GOCHANG 01, 02, 04 and 05), cluster 2 (SEOCHEON 06, 07, 08, 09 and 10), cluster 3 (TAEAN 11, 12, 13, 14 and 15) and cluster 4 (ANMYEON 16, 17, 18, 19, 20 and GOCHANG 03). Multiple comparisons of average bandsharing values among Manila clam populations from four sections were generated according to the bandsharing values and similarity matrix. Ultimately, individuals from SEOCHEON clam population (0.637±0.227) exhibited higher bandsharing values than did individuals from GOCHANG clam population (0.402±0.115) (P<0.05).

Seven oligonucleotides primers were shown to generate the shared loci, specific loci, unique shared loci to each species and shared loci by the three species which could be obviously scored. In the present study, 7 oligonucleotides primers produced 401 total loci in the Styela clava (SC) species, 390 in the Halocynthia roretzi (HR) and 434 in the Styela plicata (SP), respectively. Seven oligonucleotides primers generated 275 specific loci in the SC, 341 in the HR and 364 in the SP species, respectively. The oligonucleotides primer BION-23 generated 28 unique loci to each species in the SP species. Especially, the oligonucleotides primer BION-25 produced 7 unique loci to each species, which were identifying each species in the SP species. BION-17 distinguished 21 shared loci by the three ascidian species, major and/or minor fragments of sizes, which were identical in almost all of the samples. Based on the average bandsharing values of all samples, the similarity matrix ranged from 0.519 to 0.774 in the SC species, from 0.261 to 0.683 in the HR species and from 0.346 to 0.730 in the SP species. As regards average bandsharing value (BS) results, individuals from SC species (0.661±0.081) exhibited higher bandsharing values than did individuals from HR species (0.555±0.074) (P<0.05). The dendrogram obtained by the seven oligonucleotides primers indicates three genetic groups. In three ascidian species, the shortest genetic distance (0.071) exhibiting significant molecular difference was also between individual no. 20 and no. 21 within the SP species.

Genomic DNA samples isolated from geographical purplish Washington clam (Saxidomus purpuratus) were obtained from three different regions in the Korean Peninsula: Geoje (Geoje population; GJP), Gunsan (Gunsan population; GSP) and a site of North Korea (North Korea population; NKP). The seven primers generated the total 369 loci that can be scored from the GSP clam population. 356 fragments were generated from the NKP clam population. The complexity of the banding patterns varies dramatically between the primers and three localities. In this study, 319 loci were identified in the purplish Washington clam from Geoje and 369 in the clam population from Gunsan: 221 specific loci (69.3%) in the GJP clam population and 300 (81.3%) in the GSP population. These results demonstrate that the primer detected a large quantity of specific fragments, suggesting that the genetic variation in the GSP is higher than in the GJP population. In particular, the BION-28 primer gave DNA profiles with more fragments than the other six primers in the NKP population. The oligonucleotides primer BION-75 produced 21 unique loci to each population, which were ascertaining each population, approximately 250 bp, 300 bp and 400 bp, in the GJP population. Outstandingly, the primer BION-50 detected 21 shared loci by the three populations, major and/or minor fragments of sizes 150 bp, which were matching in all samples. With regard to average bandsharing value (BS) results, individuals from GJP population (0.743) displayed higher bandsharing values than did individuals from GSP population (0.606). In the present study, the dendrogram gained by the seven oligonucleotides primers indicates three genetic clusters: cluster 1 (GEOJE 01 ~ GEOJE 07), cluster 2 (GUNSAN 08 ~ GUNSAN 14), cluster 3 (N.KOREA 15 ~ N.KOREA 21). Among the twenty one clams, the shortest genetic distance that revealed significant molecular differences was between individuals 08 and 09 from the NKP population (genetic distance = 0.073), while the longest genetic distance among the twenty-one individuals that demonstrated significant molecular differences was between individuals GEOJE no. 03 and GUNSAN no. 09 (genetic distance = 0.669). Comparatively, individuals of GJP population were properly closely related to that of NKP population, as revealed in the hierarchical dendrogram of genetic distances. In due course, PCR analysis has revealed the significant genetic distance among three purplish Washington clam populations. PCR fragments discovered in this study could be valuable as a DNA marker of the three geographical clam populations to distinguish.

Genomic DNAs were extracted from the muscle of twenty-one specimens of three eel species collected in Anguilla japonica (AJ), Muraenesox cinereus (MC) and Conger myriaster (CM) from the Yellow Sea, respectively. In the present study, 7 oligonucleotides primers generated 191 specific loci in the AJ species, 226 in the (MC) species and 181 in the CM species, respectively. The primer BION-02 generated the most loci (a total of 83), with an average of 11.86 in the AJ species. The specific loci generated by oligonucleotides primers exhibited inter-individual-specific characteristics, thus revealing DNA polymorphisms. With regard to average bandsharing value (BS) results, individuals from Conger myriaster species (0.808) exhibited higher bandsharing values than did individuals from Muraenesox cinereus species (0.729) (P<0.05). The longest genetic distance (0.430) displaying significant molecular difference was also between individual no. 01 within Anguilla japonica eel species and individual no. 04 within Anguilla japonica species. In this study, the dendrogram resulted from reliable seven oligonucleotides primers, indicating three genetic clusters composed of group I (ANGUILLA 01~ANGUILLA 07), group II (MURAENESOX 08~MURAENESOX 14) and group III (CONGER 15~CONGER 21). The existence of species differentiation and DNA polymorphisms among three eel species were detected by PCR analysis. As mentioned above, a dendrogram revealed close relationships between individual identities within three eel species. High levels of a significant genetic distance among three eel species showed this PCR approach is one of the most suitable tools for individuals and/or species biological DNA studies.

Three eel species such as Anguilla japonica (AJ), Muraenesox cinereus (MC) and Conger myriaster (CM), belonging to the order Anguilliformes, are the most popular marine products in Korea because of their taste and nutritional value, and Koreans consume them in large quantities. Eel, ecologically important warm water fish species widely distributed on the coast of the Yellow Sea, southern sea and the several sea areas under the natural ecosystem. However, in spite of their economic and scientific consequences, a little information currently exists regarding the genetic levels only of eel species in Korea. In this study, to explicate the genetic distances and differences among geographical eel species, the author accomplished a clustering analysis of three eel species collected from the Yellow Sea. PCR analysis was performed on DNA samples extracted from a total of 21 individuals using seven oligonucleotides primers. Muscle tissues were obtained separately from individuals from Anguilla japonica, Muraenesox cinereus and Conger myriaster, respectively. Eel muscle was collected in sterile tubes, instantaneously placed in liquid nitrogen, and stored at －40℃ until the genomic DNA extraction. Genomic DNA was extracted and purified under the conditions described previously (Yoon, 2008). After several washings, lysis bufferⅠ (155 mM NH4Cl; 10 mM KHCO3; 1 mM EDTA) was added to the samples, and the mixture tubes were gently inverted. The concentration of the extracted genomic DNA was measured by optical density at 260 nm by a spectrophotometer (Beckman Coulter, Buckinghamshire, UK). PCR was performed using two Programmable DNA Thermal Cyclers (MJ Research Inc., Waltham, MA, USA). Euclidean genetic distances within- and between-species were also calculated using the hierarchical dendrogram program Systatver.10 (SPSSInc., Chicago, IL, USA). Seven oligonucleotides primers were shown to generate the shared loci, specific loci, unique shared loci to each species and shared loci by the three species which could be obviously scored. In the present study, 7 oligonucleotides primers generated 191 specific loci in the AJ species, 226 in the MC species and 181 in the CM species, respectively. The specific loci generated by oligonucleotides primers exhibited inter-individual-specific characteristics, thus revealing DNA polymorphisms. The gDNA isolated from three eel species were amplified by PCR. Here, the seven oligonucleotide primers were used to generate the unique shared loci to each species and shared loci by the three eel species. With regard to average bandsharing value (BS) results, individuals from Conger myriaster species (0.808) exhibited higher bandsharing values than did individuals from Muraenesox cinereus species (0.729) (P<0.05). The dendrogram resulted from reliable seven oligonucleotides primers, indicating three genetic clusters composed of group I, group II and group III. The longest genetic distance (0.430) displaying significant molecular difference was also between individual no. 01 within Anguilla japonica eel species and individual no. 04 within Anguilla japonica species. From what has been said above, the potential of this analysis to ascertain diagnostic markers for the identification of three eel species has also been verified (McCormack et al., 2000; Yoon, 2008).

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.

The twenty-one individuals of Meretrix lusoria were secured from Gunsan, Shinan and Yeonggwang on the coast of the Yellow Sea and the southern sea in the Korean Peninsula, respectively. Amplification of a single COI fragment (720 bp) was imagined, and no apparent size differences were observed in amplified fragments between Meretrix lusoria and M. petechialis individuals. The size of the DNA fragments also varied excitedly, from 200 to 1,600 bp. The oligonucleotides primer BION-08 produced the least loci (a total of 17), with an average of 2.43 in the Gunsan population, in comparison to the other primers used. Remarkably, the primer BION-13 detected 42 shared loci by the three populations, major and/or minor fragments of sizes 200 bp and 400 bp, respectively, which were identical in all samples. The dendrogram gained by the seven oligonucleotides primers highlight three genetic clusters: cluster 1 (GUNSAN 01 ~ GUNSAN 07), cluster 2 (SHINAN 08 ~ SHINAN 14) and cluster 3 (YEONGGWANG 15 ~ YEONGGWANG 21). The longest genetic distance among the twentyone Meretrix lusoria individuals that displayed significant molecular differences was between individuals GUNSAN no. 01 and SHINAN no. 14 (genetic distance = 0.574). Comparatively, individuals of SHINAN population were fairly closely related to that of YEONGGWANG population. In this study, PCR analysis has discovered significant genetic distances between two white clam population pairs (P<0.05).

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).