• Journal of Species Research
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• v.3 no.2
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• pp.127-166
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• 2014

Moniligastrids are an important yet often ignored earthworm group commonly found in cultivated soils, especially paddy, in the tropical East. Seven new taxa are: Drawida koreana austri, D. koreana nanjiro, D. koreana shindo, D. odaesan, D. jeombongsan, D. companio and D. csuzdii Blakemore spp. or sub-spp. nov. from Korea. Drawida csuzdii is the first new species from North Korea since Lumbricidae Eisenia koreana (Zicsi, 1972). Historical East Asian moniligastrids are reviewed chronologically and Drawida barwelli (Beddard, 1886), D. japonica (Michaelsen, 1892) and D. siemsseni Michaelsen, 1910 are compared on their museum types. These three taxa were thought similar and related to D. nepalensis Michaelsen, 1907 and its possible synonym D. burchardi Michaelsen, 1903 (priority!) and both of these to prior D. uniqua (Bourne, 1887). Indian Drawida calebi Gates, 1945 is compared to new material of D. japonica from Japan, and D. willsi Michaelsen, 1907 to the new sub-species of D. koreana Kobayashi, 1938 from Korea. Where available, mtDNA COI gene barcodes are provided to help objective determinations and a phylogram is provided with outgroup Ocnerodrilidae Eukerria saltensis (Beddard, 1895) itself found in rice paddy/irrigation. The challenge now is comparison of all early taxa in their various homelands in order to assess the genetic variability and taxonomic boundaries acceptable, especially for unpigmented D. barwelli and also for pink/grey D. japonica and blue/grey D. koreana. A checklist of moniligastrids is appended showing 22 species from China (including Hainan and Taiwan), 21 from Korea, nine from Japan and the Drawida ghilarovi Gates, 1969 species-complex from far eastern Russian (Siberia). Recent Drawida dandongensis Zhang & Sun, 2014 from Sino-Korean border is misdescribed and cannot be meaningfully compared to any other Drawidas.

• Korean Journal of Ichthyology
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• v.29 no.4
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• pp.244-251
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• 2017

A total of 15 larvae [3.53~19.49 mm standard length (SL)] belonging to the family Bothidae collected from the southern sea of Korea in 2016 were identified as Psettina tosana based on 434 base-pair sequences of mitochondrial DNA cytochrome c oxidase subunit I. Larvae of Psettina tosana have anterior-most two elongated dorsal fin rays. Uniserial melanophores present on the dorsal and anal fin base, whereas melanophores on the body absent. An inflection point in the relative growth of head length and head depth against SL was shown between 9.93 mm and 10.73 mm SL. The examined larvae of Psettina tosana are clearly distinguished from the most similar species, Psettina iijimae in having no melanophore patches in the proximity of dorsal and anal fin base.

• International Journal of Industrial Entomology and Biomaterials
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• v.14 no.2
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• pp.107-112
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• 2007

The mole crickets, Gryllotalpa, are insect pest distributed in the world. In Korea, G. orientalis was reported to occur, but previous ecological studies suggested the presence of two ecological types. To test this hypothesis, we sequenced a portion of mitochondrial (mt) genome from 48 G. orientali individuals collected over five Korean localities: Busan, Suwon, Okchon, Wonju, and Gangneung. From the sequence analysis, only two haplotypes were obtained, but the sequence divergence between the two haplotypes was 11 %, suggesting the presence of two distinct genetic groups in Korea. Although the population of Busan, Okchon, Wonju, and Gangneung was identified as a single haplotype, but that of Suwon was occupied by both hapotypes. Considering sequence divergence of other insect species occurring in Korea, the divergence estimate found between the two haplotypes seems to be too large to be considered as identical species. This result may suggest that the two differentiated haplotypes found in this study may reflect the previously reported two ecological types found in Suwon, Korea. To further understand the genetic divergence of the two phylogenetic groups, analysis of more variable regions of G. orientalis genome is required.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.4
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• pp.467-479
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• 2021

The distribution and abundance of fish eggs and larvae were investigated from February to December 2020 along the coastal waters of Korea. The eggs and larvae were identified using the mitochondrial DNA cytochrome c oxidase subunit I (mtDNA COI) and 16s rRNA gene. During the study period, eggs of overall 45 taxa belonging to 26 families were collected and larvae of overall 39 taxa belonging to 23 families were collected. In Yeongil Bay, eggs of Engraulis japonicus, which accounted for 83.9% of the total population, was the most dominant species, followed by Sardinops sagax (4.0%), Repomucenus valenciennei (3.8%) and E. japonicus larvae, which accounted for 34.9% of the total population. These were followed by Sebastiscus marmoratus (31.0%). In Gomso Bay, E. japonicus eggs accounted for 61.7% of the total population, followed by Sillago japonica (14.0%), Johnius grypotus (8.8%) and Pholis fangi larvae, which accounted for 53.5% of the total population, followed by Ammodytes personatus (34.1%). In Jinhae Bay, E. japonicus eggs accounted for 86.0% of the total population, followed by Leiognathus nuchalis (4.1%), Konosirus punctatus (3.7%) and E. japonicus larvae, which accounted for 48.7% of the total population, followed by Parablennius yatabei (21.6%).

• Korean Journal of Environment and Ecology
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• v.31 no.5
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• pp.461-471
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• 2017

Population genetic studies of 10 groups of Iksookimia pacifica were conducted to investigate the genetic diversity and population genetic structure across its known range in South Korea. Population DNA sequences of one mitochondrial gene (mtCOI) and three nuclear genes (IRBP, EGR2B, RAG1) were examined in samples collected from ten streams that flow into the East Sea. Both mitochondrial and nuclear sequences exhibited significant differentiation among populations except a few cases. The Bayesian analysis of the multi-locus genotypes inferred from the DNA sequences of nuclear genes clustered the individual fish largely into two geographical groups: a northern group (from Baebong stream to Cheonjin stream) and a southern group (Yangyangnamdae stream to Gangneungnamdae stream). Given that the streams flowing into the East Sea are geographically isolated water systems, such separation of genotypes can be interpreted by the geographical separation of common ancestors into north and south that had colonized South Korea. Since the initial geographical separation of the ancestral population by north and south, the ancestral groups seem to have experienced further differentiation into the current genetic clusters through the physical isolation of streams by the East Sea in each region. It is notable that many individuals in the Jasan stream formed a genetic cluster with those of Yangyangnamdae and Gangneungnamdae streams which are distant from each other. In addition, mitochondrial gene showed low genetic differentiation between some neighboring populations and very low level of genetic diversity in several populations. The present population genetic study will provide valuable information for the conservation and management of the Korean endemic fish species, I. paicifica.

• Ocean and Polar Research
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• v.40 no.4
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• pp.213-222
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• 2018

We investigated seasonal variations in the abundance of the adults and the resting eggs of copepods to understand the role of copepod resting eggs for maintaining their population inhabiting the coastal area of Dadaepo, Korea. Adults and resting eggs of copepods were collected bi-monthly with a conical net (45 cm mouth diameter, $330{\mu}m$ mesh size) and van Veen grab ($0.1m^2$ area), respectively, from October 2016 to September 2017. The species of resting eggs were identified using mtCOI gene. The mean abundance of copepods was highest in October ($3686{\pm}1190inds{\cdot}m^{-3}$) and lowest in January ($176{\pm}60inds{\cdot}m^{-3}$) with the dominance of Paracalanus parvus s.l.. Among copepod producing resting eggs, Acartia omorii and Centropages abdominalis were dominant. The mean abundance of resting eggs was the highest in July ($9148{\pm}6787eggs{\cdot}m^{-2}$) and the lowest in October ($530{\pm}348eggs{\cdot}m^{-2}$). Most of the collected resting eggs were identified as A. omorii's. The mean abundances of A. omorii adults and resting eggs were highest in July, and both abundances fluctuated in a similar pattern except in September. In September, A. omorii adults were observed in a state of low abundance, while their resting eggs occurred in a state of high abundance. These results suggest that A. omorii maintain their population by producing a large quantity of resting eggs, particularly diapause eggs, before the seawater temperature rises. These eggs would hatch and be newly recruited to their population when the environmental condition becomes favorable.

• Korean Journal of Ecology and Environment
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• v.56 no.2
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• pp.140-150
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• 2023

The Hangang River^* is necessary to manage the water environment of severe pollution due to the high density of residential areas, parks, and agriculture and the large population concentrated there. Benthic macroinvertebrates, such as chironomids larvae, are bioindicator species that reflect environmental changes and are crucial for water quality monitoring. In this study, we investigated morphological characteristics and molecular analysis of the chironomids larvae inhabiting the Hangang River area for water environment surveys. For this research, 20 rivers, lakes, and urban area in the Hangang River basin were selected. Chironomids larvae were collected from July to September 2022, and their appearance and characteristics were identified through morphological identification. In addition, phylogenetic analysis was performed based on the mtCOI gene sequences of the collected chironomids larvae, and identification at the genus level was confirmed. As a result, 32 species and 18 genera of 3 subfamilies of Chironomidae larvae were identified, and Stictochironomus sp. dominated most sites(6 sites). The morphological characteristics of the identified chironomids larvae, such as the mentum, ventromental plate, and antenna, were organized into table and pictorial keys, and a Bayesian inference molecular phylogeny was presented. These results provide basic morphological information for genus-level identification and can be used as fundamental information for water quality management.