ISSN : 1225-3480
Small streams and connected estuaries on Jeju Island off the south coast of Korea are unique habitats for some marine invertebrate animals, including the neritid gastropod Clithon retropictum (v. Martens, 1870). According to the Korean wildlife protection and management act, the estuarine gastropod C. retropictum is one of the level II endangered animals due to its vulnerable habitat. In this study, we report three small streams connected to the sea on Jeju Island, Woldaecheon stream on the north, Changgocheon on the south, and Hadori migratory bird habitat on the east coast as new habitats of C. retropictum. Egg capsules of C. retropictum were commonly observed in the newly found habitats, although the density in each habitat was low, with less than one individual per m2. Along with the previously reported habitats of C. retropictum on Jeju Island, those new habitats require special attention to protect from anthropogenic activities which may deteriorate and destroy the habitat.
The mollusks fauna were investigated to preserve the continuous biomass of Mytilus unguiculatus that are native to Yeongsan Island, Biosphere Reserve. The habitat competitors and predators affecting the survival of wild M. unguiculatus in Yeongsan Island were investigated. Therefore, the results of this study will be used as data for the continuous production of mussels in Yeongsan Island.
The PANM database (Protostome DB) is a public database platform established in 2015 for the efficient annotation of next-generation sequencing (NGS) data arising from genome sequencing projects involving the Invertebrates (include Arthropoda, Mollusca, and Nematoda). The database has been updated on a routine basis to further increase the accuracy and speed of NGS data annotation. In PANM DB version 5.0 release a total of 21,276,123 protein sequences belonging to the Protostomes have been made available (registered sequences of NCBI). The PANM DB version 5.0 contains about 4% of the total NCBI-nr data shortening the time for overall annotation of large-scale NGS data of the Protostomes. PANM DB version 5.0 can be downloaded for free from http://panm.sch.ac.kr/ for annotation based on local BLAST analysis.
This study was conducted to develop microsatellite markers in Crassostrea gigas using next-generation sequencing. A total of 46,335,655,445 bp reads were generated on an Illumina Hiseq x ten system, yielding 600,863,377 bp sequences. The de novo assembly resulted in 30.636 contigs. A total of 261 contigs, including 56 microsatellite loci, were derived from 30,636 contigs longer than 518 bp. A total of 22 polymorphic nuclear microsatellite markers were chosen to evaluate population genetic parameters in the farm. The mean number of effective alleles was 9, ranging from 3 to 25. The observed heterozygosity (HO) and expected heterozygosity (HE) ranged between 0.104 and 0.896 with an average of 0.469 and from 0.214 to 0.947 with an average of 0.579, respectively. No significant linkage disequilibrium was observed after Bonferroni revision in any loci. The results show that the 22 polymorphic nuclear microsatellite markers can be used to study the population and conservation genetics of Crassostrea gigas in Korea. The analysis of polymorphic SSR could provide an important experimental tool for examining a range of issues in Crassostrea gigas genetics
One of the most important estimations in forensic studies of marine criminal evidence is the postmortem interval (PMI). Here we analyzed the time estimation relevance using biofouling process. To this end, four different material panels (pvc, SUS, wood, and cloth), all in the same size 10 × 10 cm2, were immersed in sea area at a depth of 1.5 m. Fouling patterns of the mussels Mytilus galloprovincialis were investigated every month and the new panels were immersed. Based on ASTM methods, the fouling mussels were measured for shell length and populations. As a result, we found that there was a significant difference in the density and growth of the mussels depending on the dumping time (F = 56.609, p = .000). Therefore, these findings can be feasible for use in marine scientific investigations such as PMI, finding criminal, and crime details.
In this study, we evaluated the bacteriological safety of seawater and abalone in Bogil-Nohwa area from August 2020 to July 2022 and calculated the effect of inland pollution sources on seawater and abalone in this area. We analyzed the indicator bacteria of fecal contamination such as coliform group, Fecal coliform and Escherichia coli (E. coli) in the seawater, abalone and discharge water of major inland pollutants. In 726 seawater samples, the range of coliform group and Fecal coliform was all < 1.8-920 MPN/100 mL, and the calculated geometric mean and the estimated 90th percentile ranges of coliform group and Fecal coliform were < 1.8-5.6, < 1.8-32 and < 1.8-.0, < 1.8-13 MPN/100 mL, respectively. The range of coliform group, Fecal coliform and E. coli levels for 87 abalones was < 18-3,500, < 18-45 and < 18-20 MPN/100 g respectively, and the range of plate count was < 30-3,600 CFU/100 g. The range of Fecal coliform and radius in impacted area of 7 contaminants was < 1.8-35,000 MPN/100 mL and 2-2,202 m, respectively.
This study attempted to confirm the growth characteristics according to different origin of cultchless oyster spat with off-bottom culture on West coast tidal flat using wild diploid, artificial diploid and artificial triploid spat. Oyster spats from different origin were compared with growth characteristics such as shell height, whole weight, flesh weight and survival rate. Round index and Cup index were also investigated to evaluate marketability. As a result of this experiment, the survival rate was 84-89%, and there were no difference between spat origins. The final shell height was 56.27 ± 5.45 mm for artificial triploid spat, 44.20 ± 2.66 mm for wild diploid spat and 26.15 ± 4.27 mm for artificial diploid spat, respectively. Artificial triploid spat increased by 56% compared to the initiation of an experiment, showing the highest growth rate in shell height. Among the shell shape indices, Round index was in the range of 60.70-64.08%, and there was no difference between spat origin and artificial diploid spats showed the highest value. Cup index was in the range of 36.94-41.90%, with no difference between spat origin, and artificial diploid spat showed the highest value.