• Korean Journal of Ichthyology
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• v.2 no.1
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• pp.63-76
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• 1990

Studies on the microdistribution, distributional aspect and affinity of Korean endemic species, SHIRl, Coreoleueiseus splendidus in th southern half of the Korean peninsula were carried out from May, 1966 to November, 1989. This species was found in 14 independent rivers and streamlets of the south Korea ; Yimjin R., Han R., Kum R., Ungchun S., Mangyung S., Dongjin R., Somjin R., Kwangyang East S., Sachun S., Gonyang S., Nakdong R., Samchukosip S., Samhwa S. of Namhae Island and Guchun S. of Geojae Islands, and were not found from Youngsan R., Ansung S. and Sabgyo S. This species was not common and independent comprising less than 25% of the total fish population in all habiting sites. Distributional zone was in the middle or upper streaches of main streams and tributaries. The average slope of distributional zone was 2.6, minimum slope was 0.29 and maximum slope was 5.56. Thirty-three species were found to occur along with this fish and 10 species of them occurred with more than 50% frequency. They were; 20 sp. of Cyprinidae, 5 sp. of Cobitidae, 1 sp. of Salmonidae, 1 sp. of Bagfridae, 1 sp. of Siluridae, 2 sp. of Amblycipitidae, of Serranidae, and 1 sp. of Eleotridae. Some species of fish appeared to have the same ecological position even though they have different distributional zones. These species were as follows; Acheilognathus signifer and A. limbata, Micriophsogobio koreensis and M. yaluensis in Cyprinidae, Cobitis koreensis, C. longicorpus, C. rotundicaudata in Cobitidae, Liobagrus andersoni and L. mediadiposalis in Amblycipitidae.

• Journal of Life Science
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• v.26 no.11
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• pp.1320-1329
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• 2016

The present study examined the cytotoxic effects of 1, 2, 3, 4, 6-penta-O-galloyl-${\beta}$-D-glucose (PGG), known as the pentahydroxy gallic acid ester of glucose, in the various human cancer cell lines (A-549, MDA-MB-231, U87-MG, MCF-7 and PANC-1), normal MRC-5 fetal fibroblasts, and dental papilla tissue- derived mesenchymal stem cells (DPSCs). Significantly (p<0.05) lower half maximal inhibitory concentration ($IC_{50}$) values were observed in the A-549 and MDA-MB-231 cells showing a high proliferation capacity, compared with other cancer and normal cell lines with a relatively low proliferation capacity. The population doubling time (PDT) was significantly (p<0.05) higher in the $10{\mu}M$ PGG-treated cell lines than those of untreated control cell lines. The present study demonstrated that the $IC_{50}$ value increases proportionally to the extending PDT. A high cell number with senescence-associated ${\beta}-galactosidase$ activity was also observed in the $10{\mu}M$ PGG-treated cells compared with those of untreated control cells. Moreover, the level of telomerase activity was significantly (p<0.05) decreased with $10{\mu}M$ PGG treatment, especially in A-549 and MDA-MB-231 cells showing a high proliferation capacity. Based on these observations, PGG could serve as a potent agent for cancer chemotherapy, as its treatment was more effective in cells with a high proliferation capacity.

• Korean Journal of Environment and Ecology
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• v.29 no.5
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• pp.703-709
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• 2015

A breeding pair of the Black-faced Spoonbill Platalea minor was firstly recorded on Chilsando Islands, Younggwang, Jeollanamdo Province in 1991. Since the mid 2000s, breeding population on the breeding sites has gradually increased. This study was conducted to identify breeding status and nest site characteristics of the species from May to August, 2013 on Chilsando Islands. We recorded number of nests, length and width of the nest base, slope around the nests, nest materials, distances from the nearest nest, presence of nest cover and nesting area. In 2013 breeding season, 25 of 49 nests produced at least one successful fledging. A total of 55 youngs were successfully fledged and number of fledging per nest was 2.20 individuals. Nesting area was $77.8m^2$ and $93.4m^2$ for Sansando and Yuksando Islet, respectively. Soil and soil mixed with tree root were preferred for substrate of nest base over rock and Brassica napus was dominantly selected as nest materials by Black-faced Spoonbills. Nest characteristics of 22 nests in Sasando and Yuksando Islet varied $49.59{\pm}6.53cm$(mean${\pm}$SD) for length of nest base, $41.00{\pm}5.82cm$ for width of nest base, $20.85{\pm}9.96^{\circ}$ for slope above the nest, $34.09{\pm}17.75^{\circ}$ for slope below the nest and $130.82{\pm}84.17cm$ for distances from the nearest nest. Fifteen pairs (68.2%) occupied where nest cover existed. Nest cover were located in front of the nest for 5 pairs, back of the nest for 9 pairs and both front and back of the nest for 1 pair.

• Korean Journal of Ecology and Environment
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• v.43 no.1
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• pp.82-90
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• 2010

The ecological characteristics of the Korean Aucha perch, Coreoperca herzi, were determined in order to estimate stock of the mid-upper system of the Seomjin River. The age was determined by counting the otolith annuli. The oldest fish observed in this study was 5 years old. Relationships between body length (BL) and body weight (BW) were $BW=0.0195BL^{3.08}$ ($R^2=0.966$) (p<0.01). Relationships between the otolith radius (R) and body length (BL) were BL=3.882R+1.66 ($R^2=0.944$). The von Bertalanffy growth parameters estimated from a non-linear regression method were $L_{\infty}=19.68\;cm$, $W_{\infty}=188.64\;g$, $K=0.17\;year^{-1}$ and $t_0=-1.46$ year. Therefore, growth in length of the fish was expressed by the von Bertalanffy's growth equation as $L_t=19.68$ ($1-e^{-0.17(t+1.46)}$) ($R^2=0.997$). The annual survival rate (S) was estimated to be $0.666\;year^{-1}$. The instantaneous coefficient of natural mortality (M) of estimated from the Zhang and Megrey method was $0.346\;year^{-1}$, and instantaneous coefficient of fishing mortality (F) was calculated $0.061\;year^{-1}$. From the estimates of survival rate (S), the instantaneous coefficient of total mortality(Z) was estimated to be $0.407\;year^{-1}$.

• Journal of Aquaculture
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• v.6 no.4
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• pp.235-253
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• 1993

The freshwater crab, Eriocheir japonicus inhabits from sub-tropical to temperate zone in Asia. This species belongs to a large size group among freshwater crabs. Common size of this crab is 5-6cm in carapace length and occasionally 7cm in carapace length. This species of crab used to inhabit in estuaries, rivers and inland waters in Korea. However, natural population recently has been rapidly decreased because of pollution and lost their habitats by suburban development. Therefore, development of proper methods of seedling production to increase natural stock became necessity. As parts of achieving this goal, duration from mating to spawning, egg incubation period, and egg development of this species were studied. The influence of temperatures and salinities on the egg incubation and hatching was also investigated. It took 2-8 hours from mating to egg spawning and the spawning lasted 3-9 hours from the first spawning. Egg numbers per female (6cm in carapace length) were 380,000­410,000. Optimum temperature for egg incubation was $17\~23^{\circ}C$ and optimum salinity, $14.0\~31.5\%o$. Incubation period of the eggs at $14^{\circ}C,\;17^{\circ}C,\;20^{\circ}C,\;26^{\circ}C,\;and\;28^{\circ}C$ was 42, 28, 21, 15, and 14 days. respectively. Relation between temperature (X) and incubation days (Y) was LogY = Log 2764.267 - 1.608 LogX. A female can spawn 4-6 times per year by manipulation of environmental conditions. Under the conditions of $18^{\circ}C\;and\;24.5\%o$, it took 6 days up to embryo formation, 18 days up to compound eye formation, 22 days up to abdominal movement, and 25 days up to hatch out as zoea larvae.

• Korean Journal of Environment and Ecology
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• v.21 no.3
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• pp.197-206
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• 2007

This study was conducted to survey the population of water birds wintering at the seven coastal wetlands of Jeollanam province including Suncheon Bay and Yeongsan Lake, from 2000 through 2003. The 90 species and 857,570 individuals in total were sighted at the seven survey sites. We classified the wintering water birds into seventeen groups of taxa based on the similar ecological attributes, among which, eight groups were found to inhabit the water surface or riparian areas. Classified groups that showed higher rate of using bay areas than that of lake areas were in the order of waders, gulls and swans. On the other hand, the groups that showed higher rate of using lake areas than that of using bay areas were revealed in the order of dabbling ducks, grebes and geese. In conclusion, there was a difference in the pattern between the two classified groups. As a result of the UPGMA cluster analysis using CCs ($S{\varnothing}rensen'a$ index of similarity and Ro (Horn's index of community overlap), the results showed that Suncheon Bay had the most unique species formation out of the seven areas. Bay and lake areas were different from each other in the formation of species and Individuals. As a result of combining the index rank according to the maximum aggregate count, the Suncheon Bay is ranked the highest in importance of the habitats for water birds, followed by the order of Boseong-Deukryang Bay, Gangjin Bay, Gocehongam Lake, Geumho Lake, Yeomam Lake, and Yeongsan Lake. Considered overall, the importance of the bay areas was relatively higher than that of reclaimed lake areas.

• Korean journal of applied entomology
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• v.50 no.4
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• pp.343-352
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• 2011

The developmental period of Laodelphax striatellus Fallen, a vector of rice stripe virus (RSV), was investigated at ten constant temperatures from 12.5 to $35{\pm}1^{\circ}C$ at 30 to 40% RH, and a photoperiod of 14:10 (L:D) h. Eggs developed successfully at each temperature tested and their developmental time decreased as temperature increased. Egg development was fasted at $35^{\circ}C$(5.8 days), and slowest at $12.5^{\circ}C$ (44.5 days). Nymphs could not develop to the adult stage at 32.5 or $35^{\circ}C$. The mean total developmental time of nymphal stages at 12.5, 15, 17.5, 20, 22.5, 25, 27.5 and $30^{\circ}C$ were 132.7, 55.9, 37.7, 26.9, 20.2, 15.8, 14.9 and 17.4 days, respectively. One linear model and four nonlinear models (Briere 1, Lactin 2, Logan 6 and Poikilotherm rate) were used to determine the response of developmental rate to temperature. The lower threshold temperatures of egg and total nymphal stage of L. striatellus were $10.2^{\circ}C$ and $10.7^{\circ}C$, respectively. The thermal constants (degree-days) for eggs and nymphs were 122.0 and 238.1DD, respectively. Among the four nonlinear models, the Poikilotherm rate model had the best fit for all developmental stages ($r^2$=0.98~0.99). The distribution of completion of each development stage was well described by the two-parameter Weibull function ($r^2$=0.84~0.94). The emergence rate of L. striatellus adults using DYMEX$^{(R)}$ was predicted under the assumption that the physiological age of over-wintered nymphs was 0.2 and that the Poikilotherm rate model was applied to describe temperature-dependent development. The result presented higher predictability than other conditions.

• Korean Journal of Ecology and Environment
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• v.56 no.2
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• pp.172-186
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• 2023

Small ponds, which exhibit unstable succession pattern of plankton community, are less well studied than large lakes. Recently, the importance of small ponds for local biodiversity conservation has highlighted the necessity of understanding the dynamics of biological community. In the present study, we collected zooplankton from three small reservoirs with monthly basis and analyzed their seasonal dynamics. To understand the complicated zooplankton community dynamics of small reservoirs, we categorized zooplankton species into four groups (LALF Group, Low Abundance Low Frequency; LAHF Group, Low Abundance High Frequency; HALF Group, High Abundance Low Frequency; HAHF Group, High Abundance High Frequency) based on their occurrence pattern (abundance and frequency). We compared the seasonal pattern of each group, and estimated community diversity based on temporal beta diversity contribution of each group. The result revealed that there is a relationship between groups with the same abundance but different occurrence frequencies, and copepod nauplii are common important component for both abundance and frequency. On the other hand, species included with LALF Group throughout the study period are key in terms of monthly succession and diversity. LALF Group includes Anuraeopsis fissa, Hexarthra mira and Lecane luna. However, groups containing species that only occur at certain times of the year and dominate the waterbody, HALF Group, hindered to temporal diversity. The results of this study suggest that the species-specific occurrence pattern is one key trait of species determining its contribution to total annual biodiversity of given community.

• Food Science and Preservation
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• v.22 no.2
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• pp.218-224
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• 2015

Crickets have been used as crude drug for treating fever and hypertension in East Asia. This study was carried out to investigate the quality characteristics such as the microbial and nutrient contents of crickets (Gryllus bimaculatus) prepared with various processing conditions for use as food. These conditions included the lyophilization process (LP), hot-air process (HP, $90^{\circ}C$ for 7 hr), roasting process (RP, $160^{\circ}C$ for 40 min), and frying process (FP, $180^{\circ}C$ for 30 sec). The total bacterial population of the crickets was 5~7 log CFU/g, but Coliform and E. coli were not detected. The major fatty acids in all the samples were palmitic acid (C16:0), oleic acid (C18:1), and linoleic acid (C18:2). The level of polyunsaturated fatty acids was highest (63.55 g/100 g) in the LP-processed crickets. As for the amino acid content, the glutamic acid level was highest in all the samples, and the RP and FP decreased by 12.01% and 53.88%, respectively, compared to that of the LP. The mineral contents were highest in the LP-processed crickets. Hg was detected at about 1.0 ppb in all the samples, but its level was lower than the residue tolerance level in the Korean Food Code. Such conditions should be considered to better understand the quality characteristics of crickets in food processing.

• Korean Journal of Ichthyology
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• v.24 no.3
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• pp.167-176
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• 2012

In comparison of the body color of Zacco platypys from Korea, it was found that there were significant differences among geographical populations in the color of upper eye, snout tip and anterior margin of pectoral fin. In individuals with red upper eye the snout tip was red but in those with black upper eye red color did not appeared on the snout tip. There was no difference between male and female in this characteristic and it was expressed uniformly within the same population. So we divided Z. platypus into two types by the color of upper eye; R type with red upper eye and B type with black upper eye. Red band on anterior margin of pectoral fins appeared in all males of both R and B type populations but in females it appeared only in B type individuals. The two types shown different distribution pattern in Korean Peninsula. R type distributed in almost whole area but B type distributed only in southeastern part of the peninsula: Nakdong, Hyeongsan, Taehwa, Suyeong and Jinjeon River. In analysis of external morphology among two types of Z. platypus from Korea and Z. platypus from Japan, there were no significant differences. But they were relatively well separated in discriminant function analysis.