• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.4
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• pp.232-238
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• 2005

This paper describes reproduction, population structure, growth and size at sexual maturity of a deep-water mud shrimp (Solenocera melantho) in the adjacent waters of Geomun Island, Korea. The shrimp was caught by a beam trawl from November 1998 to December 1999. Spawning period was estimated by gonadosomatic index to be from August to early November with a peak in October to early November. Female shrimps were $12\%$ matured at 16 mm in carapace length, $33\%$ matured at 18 mm and $75\%$ matured at 22 mm. The size at $50\%$ maturity for female was estimated to be 20.65 mm in carapace length. Breeding season was estimated to be from August to early November with a peak in October to early November. The size at $50\%$ inseminated was 19.81 mm CL. The fecundity was 87,500-405,200 and related exponentially to carapace length and total weight. This species survived between 25 and 26 months. The maximum carapace length of females and males were 48 mm and 34 mm respectively. Sex ratio was $51.3\%$, and the females were preponderant. Growth was estimated by modified von Bertalanffy growth function incorporating seasonal variation in growth in both years females (K=1.019/yr and $L_{\infty}$=51.731 mm CL) grew faster, reaching a larger size at a given age than males (K=1.848/yr, and $L_{\infty}$=27.499 mm CL). This is indicated by differences in growth performance indices $(\varphi')$ between females (3.291) and males (3.145).

• Journal of Life Science
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• v.18 no.8
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• pp.1132-1139
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• 2008

A CpG island is a short stretch of DNA in which the frequency of the CG dinucleotide is higher than other regions. CpG islands are present in the promoters and exonic regions of approximately $30{\sim}60$% of mammalian genes so they are useful markers for genes in organisms containing 5-methylcytosine in their genomes. Recent evidence supports the notion that the hypermethylation of CpG island, by silencing tumor suppressor genes, plays a major causal role in cancer, which has been described in almost every tumor types. In this respect, CpG island search by computational methods is very helpful for cancer research and computational promoter and gene predictions. I therefore developed a window program (called CpGi) on the basis of CpG island criteria defined by D. Takai and P. A. Jones. The program 'CpGi' was implemented in Visual C++ 6.0 and can determine the locations of CpG islands using diverse parameters (%GC, Obs (CpG)/Exp (CpG), window size, step size, gap value, # of CpG, length) specified by user. The analysis result of CpGi provides a graphical map of CpG islands and G+C% plot, where more detailed information on CpG island can be obtained through pop-up window. Two human contigs, i.e. AP00524 (from chromosome 22) and NT_029490.3 (from chromosome 21), were used to compare the performance of CpGi and two other public programs for the accuracy of search results. The two other programs used in the performance comparison are Emboss-CpGPlot and CpG Island Searcher that are web-based public CpG island search programs. The comparison result showed that CpGi is on a level with or outperforms Emboss-CpGPlot and CpG Island Searcher. Having a simple and easy-to-use user interface, CpGi would be a very useful tool for genome analysis and CpG island research. To obtain a copy of CpGi for academic use only, contact corresponding author.

• Korean Journal of Environment and Ecology
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• v.27 no.5
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• pp.550-560
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• 2013

This study was investigated the morphological characters, secondary sexual dimorphism, and habitat patterns of Korean Rattus animals collected on Jeju Island from April 2005 to October 2012. Two wild rat species, namely R. norvegicus and R. tanezumi were identified on Jeju Island based on morphological characteristics and molecular data; however, R. rattus, which had recorded formerly, was not found in this study. Individuals of R. norvegicus were captured from urban, rural, and natural habitats, while those of R. tanezumi were specially found in animal farms and the surrounding areas. Comparing of morphological characters of two species, R. norvegicus had a shorter tail and ears than R. tanezumi (p<0.05), and the ratios of tail length and ear length to those of head-body length showed significantly differences between two species (p<0.05). The body weights (BW) of urban populations of R. norvegicus were significantly heavier than those of rural populations (p<0.05). No secondary sexual dimorphism was found in R. norvegicus, but females of R. tanezumi showed heavier BW than those of males (p<0.05). These findings suggest that it is necessary to revise the records for the existence of R. tanezumi and to confirm the animal fauna and elucidate the distribution and ecological characteristics from further studies using extensive sampling and detailed investigations on Jeju Island and also on the Korean Peninsula.

• Development and Reproduction
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• v.17 no.2
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• pp.73-78
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• 2013

This study histologically describes the intersexuality of Scomberomorus niphonius collected from the coastal area near Jeju Island. A total of 126 S. niphonius, collected from March to July 2012 with a total length of 62.4 cm (${\pm}17.5$) and a total weight of 1,701.9 g (${\pm}1,528.9$) were used for analyses. From a histological perspective, two types of intersex were confirmed. One type had scattered germ cells from the opposite sex within the gonad. The second type developed germ cells from the opposite sex in the connective tissue of the outer gonadal membrane. The intersexuality was 14.3% (n=18/126), with females (21.3%; n=16/75) exhibiting a higher rate than males (3.9%; n=2/51). There was no displayed correlation between intersexuality and the total length and weight.

• Ocean and Polar Research
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• v.26 no.4
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• pp.685-688
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• 2004

The morphology of the post-larva of Liopropoma japonicum of the family serranidae is described from one specimen collected off Jeju Island ($32^{\circ}42'N,\;127^{\circ}45'E$) on May 3, 2001. The body is laterally compressed and caudal peduncle deep at 19.4 mm BL. Anus locates at a vertical through posteriormost(8th) dorsal-fin spine. Dorsal fin rays were VIII, 14; anal fin rays III, 10; pectroal fin rays 16; pelvic fin rays I, 5. A caudal fin is rounded. Length of elongate second and third dorsal-fin spines are 499% and 423% of the body length, respectively. A series of 50 sensory pores on body is elongated to caudal fin. Head spination is well developed. Melanophores are moderately large and dense in the head, and are small and rare in teh neck. Being freshly collected, the body color is yellowish-red and tail is semitransparent. The head is yellowish-red and the brain is dark-red.

• Animal Systematics, Evolution and Diversity
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• no.spc9
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• pp.1-9
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• 2016

Two Spirostomum species were collected from freshwater in Jindo Island, Korea and identified as Spirostomum ambiguum (Muller, 1786) Ehrenberg, 1835 and Spirostomum minus Roux, 1901. This study is the first known morphological record of these two species being found in Korea. The description is based on the observation of living specimens and protargol impregnated specimens. Diagnostics of Spirostomum ambiguum: body size $340-930{\times}45-80{\mu}m$ in vivo; long and slender body with truncated posterior part; macronucleus moniliform with 7-22 nodules; cortical granules irregularly arranged 4-5 rows in between somatic kineties; 24-58 somatic kineties arranged longitudinally; adoral zone of membranelles (AZM) covered about 60-80% of body length. Diagnostics of Spirostomum minus: body size $500-730{\times}35-45{\mu}m$ in vivo; long and slender body with truncated posterior part; macronucleus moniliform with 11-16 nodules; micronucleus 20-37 oval shape; cortical granules regularly arranged 3-4 rows in between somatic kineties; 20-30 somatic kineties arranged longitudinally; AZM covered about 40-50% of body length with 120-150 adoral membranelles.

• Korean Journal of Ichthyology
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• v.23 no.4
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• pp.310-313
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• 2011

This is the first report of Aprion virescens, belonging to the family Lutjanidae, collected in Korea. The specimen (151.4 mm in standard length) was caught by the gill net in the coastal waters of Jeju Island on 30 October, 2009. This species is characterized by having a deep vertical groove in front of eye, very short pectoral fin almost equal to snout length, and four black spots on dorsal fin. We propose a new Korean name, "Nok-saek-tung-dom-sok" and "Nok-saek-tung-dom" for the genus and species, respectively.

• Journal of fish pathology
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• v.16 no.2
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• pp.135-138
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• 2003

The research was carried out to know the occurrence trend of scuticociliatosis and mortality of fingerlings in flounder. The diseased fish were collected from on-land rearing farms lind hatcheries of flounder in Jeju Island from January 1991 to December 2001. Occurrence of scuticociliatosis was about 10% of total occurred diseases from 1991 to 1996, but increased to 34.5% in 2001. Although monthly occurrence of scuticociliatosis was not related to season from 1999 to 2001, the highest occurrence was revealed in July and August. Mixed infections of bacteria including Vibrio sp. Edwardsiella tarda, Streptococcus sp., and Flexibacter sp. with scuticociliates were observed. Among the bacteria, Vibrio sp. was the highest frequency(40.1%), and the lowest one(10.1%) was Streptococcus sp., Mortality of fingerlings by scuticociliates was different sharply according to size of fish. Mortality of infected fingerlings below 7 cm of total length was 53.8%, while that of normal fingerling above 7 cm of total length was 13.2%. When fish were grown above 25 cm, mass mortality by scuticociliates infection was decreased markedly.

• Korean Journal of Ichthyology
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• v.26 no.4
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• pp.340-344
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• 2014

A single specimen of Pseudocaranx dentex (115.8 mm in standard length), belonging to the family Carangidae, was firstly collected by a set net in the coastal waters of Jeju Island on July 14, 2014. This species was characterized by a yellow stripe presented along both sides, a single series of canine teeth arranged on jaws, a black spot on upper margin of opercle, and snout length longer than eye diameter. We newly add this species to the Korean fish fauna and propose its Korean name "Heuk-jeom-jul-jeon-gaeng-i-sok" and "Heuk-jeom-jul-jeon-gaeng-i" for the genus and species, respectively.

• Korean Journal of Ichthyology
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• v.25 no.2
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• pp.59-64
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• 2013

Two leptocephali (36.2~69.2 mm in total length) of the family Muraenidae were collected off Jeju Island, Korea. They were identified using 742 base pairs of mitochondrial DNA 12S rRNA sequences, and their morphological description were presented. The two leptocephali were identified to Gymnothorax minor based on genetic distance (d=0.000), being well consistent with that of G. minor adult collected off Tongyeong. Gymnothorax minor leptocephali are characterized by morphological combinations: total myomeres 137~139, predorsal myomeres 32, preanal myomeres 82~86, body depth in total length more than 10%.