• Korean Journal of Environment and Ecology
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• v.31 no.2
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• pp.166-173
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• 2017

Morphological and population characteristics of the Cottus koreanus were investigated at Hoam stream from October 2015 and April 2016. This is the first record on C. koreanus not only from Hoam stream (the upstream region of Daejong stream, Gyeongsangbuk-do Gyeongju-si Yangbuk-myeon Hoam-ri) but also from the stream flowing into the Samcheogosip stream, in the southern part of East Sea, Korea. The distribution of C. koreanus ranged from Girim temple to Yongyeon waterfall, about 1.2 km, and the water surface were about $3,600m^2$. The population size was assumed to 1,656 individual number, 46 object per $100m^2$. The morphometric characteristics of C. koreanus in the Hoam stream and the Han river are very similar except that the population at Hoam stream shorter head length, ventral fin ray length, pectoral fin ray length and mouth width when compared with the population at Han river. Other than that, the two populations showed the same meristic characters. Frequency analysis of total length indicated that the group with 40~59 mm in total length was one year old, the 60~79 mm was two years old, and the group over 80 mm was three years old. The average number of eggs in the ovaries was estimated as 361 (239~468) per matured female. The number of matured eggs size in ovaries was $2.6{\pm}0.21$ (23.~3.1) mm and this species was large eggs type. Calculation of the length-weight relation of C. koreanus showed the value of constant a as 0.00001 and b as 3.01, and the Condition factor (K) was 1.26 an on average.

• Korean Journal of Ichthyology
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• v.1 no.1_2
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• pp.54-63
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• 1989

Morphological variation of the crusian carp, Carassius auratus, from Yongnam area in Korea was examined. In morphometric and meristic characters, mean values were different slightly among the polulations, whereas the range of variation was overlapped largely. In the present examination the number of spines in dorsal fin were 4-6. The majority of individuals appeared to be similar to Carassius auratus langsdorfii from Japan, but some individuals were quite different from them in having 66-83 gill rakers.

• Korean Journal of Ichthyology
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• v.10 no.2
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• pp.250-259
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• 1998

This study was carried out to reveal the taxonomic status of the two mullets, Chelon affinis and Chelon haematocheilus from Korea by comparison of their morphological characteristics. Chelan affinis, occurred in the southern coastal area, is a distinct species characterized by having a keel on the middorsal line in front of the spinous dorsal fin. However, Chelon haematocheilus, found in the all coastal areas of Korea excluding Cheju island is easily distinguished from the former in having the deep flat head. By comparison of five groups of Chelan haematocheilus, Kunsan group is slightly differed from others in the height of anal fin and caudal peduncle length. Although Chelon affinis is similar with Chelan haematocheilus in the view of meristic characters, they are distinguished from each other in the number of pyloric caeca and lateral line scales.

• Animal cells and systems
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• v.14 no.3
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• pp.213-219
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• 2010

Bottlenose dolphins (Tursiops sp.) commonly inhabit Korean waters, including the coastal waters of Jeju Island. However, their taxonomic position was unclear because of the validity of this genus. The genus Tursiops has recently been determined to comprise two species: the common bottlenose dolphin (Tursiops truncatus) and the Indo-Pacific bottlenose dolphin (Tursiops aduncus). To confirm the taxonomic position of bottlenose dolphins frequenting the coastal waters of Jeju Island, the external morphology and osteology of specimens from Jeju Island were examined. Photographs of free-swimming individuals were also used for determining external morphological characters. The cranial and meristic measurements fell within the ranges of T. aduncus. Osteological ratios were also consistent with those of T. aduncus. The presence of a prominent ventral spot was observed among some individuals. As a result, the dolphins mainly distributed in the coastal waters of Jeju Island were identified as Indo-Pacific bottlenose dolphins (T. aduncus) in terms of their cranial characters and ventral spotting. We propose a new Korean name, 'Nambang-keun-dol-go-rae'.

• Korean Journal of Ichthyology
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• v.21 no.4
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• pp.273-282
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• 2009

The taxonomic review of the family Trachipteridae was carried out based on the Trachipterus ishikawae (7 specimens), Zu cristatus (4 specimens), Desmodema polystictum (2 specimens) collected from the East Sea, South Sea and adjacent waters of Jeju Island of Korea from June 2006 to August 2008. Among them, D. polystictum was revealed as an unrecorded species from Korea, being characterized by the following characters: the ventral edge smooth; body color silvery white with a lot of large dark rounded spot. We proposed the new Korean name of the genus Desmodema as "Jeom-tu-ra-chi-sog", D. polystictum as "Jeom-tu-ra-chi". Z. cristatus has a elongated first six dorsal fin and pelvic fin rays. T. ishikawae has a row of sharp tubercles along the ventral edge, and straightly elongated body form. In meristic characters, the number of dorsal fin rays were 178~195 in T. ishikawae, 137~148 in Z. cristatus and 125~130 in D. polystictum, the number of vertebrae were well distinguished among three species; T. ishikawae (80~83), D. polystictum (72~74) and Z. cristatus (65~68).

• Animal Systematics, Evolution and Diversity
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• v.5 no.2
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• pp.107-119
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• 1989

Three species of Korean sticklebacks family Gasterosteidae were reviewed based on the specimens of several populations for the study of their morphological variations and taxonomical positions. All specimens of Gasterosteus aculeatus observed have a complte row of lateral plates ranging from thirty-two to thirty-five in number. The low-plate morph regarded as landlocked type is virtually absent. And no difference was recognized among six populations of G. aculeatus in the meristic chracters, i.e. number of vertebrae, gill rakers and finrays. The Pungitius sinensis and P.kaibarae ssp. shown local variations have scutes ranging from 31 to 35, but not clinal in the morphometric characters. But P.sinensis was statistically different from P.kaibarae ssp. in some characters such as the number of dorsal spine rays and vertebrae, and body depth, although their ranges overlapped. No significant taxonomic difference was detected between white from and black from in dorsal spinous membrane of P.kailbarae ssp. Although these three species of Korean sticklebacks have the same diploid chromosome number (2N=42), G. aculeatus is obviously different from the two species of genus Pungitius in their karyotype ; G. aculeatus consists of six metacentrics, six submetacentrics, and thiry subtelo-acrocentrics, and both P.sinensis and P.kaibarae ssp. have four metacentrics, six submetacentrics, and thirty-four subtelo-acrocentrics.

• Korean Journal of Ichthyology
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• v.11 no.2
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• pp.143-148
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• 1999

Two sibling species of the genus Platycephalus collected from the South and West Sea of Korea were reviewed based on the several meristic and morphological characters, electrophoresis of muscle protein, and LDH and MDH isozyme. Counts and morphometric characters of Platycephalus indicus were different from those of Platycephalus sp. by having 18~20 pectoral fin rays (16~19 in Platycephalus sp.), 70~80 scales of lateral line (83~100), 10.2~13.1% eye diameter (10.9~15.5%), 14.5~18.1% interorbital width (11.8~17.8%), dark brown of body color (light brown) and dark brown of pectoral and ventral fin outside (light brown and pale). The number of soluble protein bands in muscle separated by polyacrylamidegel electrophoresis was 16 and 18 from P. indicus and Platycephalus sp, respectively, and each bands showed their characteristics in activated degree. The number of bands separated from LDH isozyme were 2 and 1 in P. indicus and Platycephalus sp. and in the case of MDH isozyme, 5 and 4 bands, respectively. So we were thought that P. indicus and Platycephalus sp. from Korea were different species each other.

• Korean Journal of Ecology and Environment
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• v.53 no.3
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• pp.275-285
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• 2020

Two specimens presumed to be hybrids of Rhodeus pseudosericeus and R. notatus were collected from the Sangcheon Stream of the Han River, Korea. The body color of natural hybrid individuals was yellowish brown, showing the intermediate characteristics of R. pseudosericeus and R. notatus, but overall, the characteristics of R. notatus were similar. Meristic and morphometric characters, the number of dorsal fin rays, anal fin rays and longitudinal row scales showed a hybrid index (HI) of 0, indicating the characters of R. notatus. The hybrid index of predorsal length (HI=74.6), preanal length (HI=75.3), and preventral length (HI=77.6) were similar to the characters of the R. pseudosericeus. Also four characters were appeared to have intermediate characters between R. pseudosericeus and R. notatus; number of gill rakers (HI=55.3), body depth (HI=67.9), snout length (HI=43.4), and inter orbital width (HI=44.8). The rest of 14 characters deviated between 0 and 100, showing unique characteristics of hybrid individuals. Recombination activating gene 1 (RAG1) analysis, hybrids were identified as natural hybrids due to the overlapping peaks of their parent species. Also, as a result of analysis using the cytochrome b gene (COB), one individual was derived from R. pseudosericeus, while the other was derived from R. notatus.

• Korean Journal of Ichthyology
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• v.33 no.3
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• pp.157-166
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• 2021

Three specimens, presumed to be natural hybrids between Rhodeus notatus and R. ocellatus, were collected from Onyangcheon Stream area, Jwabu-dong, Asan-si, Chungcheongnamdo, the Republic of Korea, and morphological and phylogenetic analyses were performed to clearly identify their parent species. The body color of the three natural hybrids was light greenish-brown on dorsal side, and the size of red area on the upper front of the dorsal fin and the outer margin of the anal fin generally showed intermediate characters between the parent species, R. notatus and R. ocellatus. Among the measurement and meristic characters, the ratio of prepectoral length and preanal length in the standard length, and the ratio of snout length, interorbital width, length of caudal peduncle and depth of caudal peduncle in the head length, and the number of longitudinal row scales were analyzed as the unique characters of natural hybrids. In the rag1 gene of nuclear DNA, the three natural hybrids were analyzed to be reflected all the single nucleotide polymorphism sites between R. notatus and R. ocellatus, and in the phylogenetic tree using the cytb gene of mitochondrial DNA, they formed the same genetic clade as R. notatus. Therefore, three specimens, presumed to be natural hybrids analyzed in this study were identified as interspecific hybrids between female R. notatus and male R. ocellatus.

• Korean Journal of Ichthyology
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• v.34 no.2
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• pp.73-85
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• 2022

The cynoglossid fishes are popular for food in the world including Korea, China and Japan, and among them, Paraplagusia japonica lives all over the sea of Korea. In order to establish appropriate management measure, it is essential to clarify population structure of P. japonica from the morphological and molecular perspectives. We collected a total of 132 individuals of P. japonica from six localities in Korea between 2008 and 2021. Canonical discriminant analysis results showed that the West Sea population (Incheon) slightly differed from the South (Tongyeong, Busan) and East Sea populations (Pohang, Donghae, Sokcho). Similar results were also shown in Kruskal-Wallis test of meristic characters. Furthermore, neighbor-joining and maximum-likelihood trees based on 849 base pairs of mitochondrial DNA cytochrome b sequences showed that P. japonica was divided into two lineages (designated as A and B) with a high significance (Φ_st=0.0781, P<0.001). Interestingly, however, the two lineages in the admixture area (South-East Sea) were not different in morphological characters. Our results suggest that P. japonica had undergone differentiated history during the Late Pleistocene, but secondary contact may occur at the admixture area.