• Korean Journal of Ecology and Environment
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• v.38 no.1 s.110
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• pp.11-17
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• 2005

Egg masses of C. plumosus were collected from Jungnang Stream in Seoul and reared in an incubator chamber. The larvae of C. plumosus were treated with potential endocrine disruption chemicals (EDCs) such as Diethylhexyl phthalate (DEHP), Bisphenol A (BPA) and Tebufenozide, and the effects of morphological abnormalities were observed. The deformities of the mentum following exposure to EDCs showed the smooth/round tooth, the loss of ${\ge}$1 tooth, reduced median lateral teeth (MLT) and light brown color. The incidence rates of the mentum deformity were associated with chemicals: BPA (73.7 ${\sim}$ 90.9%)>tebufenozide (57.6 ${\sim}$ 78.9%)>DEHP (46.2 ${\sim}$ 85.7%). The deformity type of the mentum showed MIX (MLT+LT, 32 ${\sim}$ 46%)>MLT (25 ${\sim}$ 34%)>LT (lateral teeth, 3 ${\sim}$ 7%). Also, the incidence of MIX type was in the order of BPA (46%)>DEHP (33%) >tebufenozide (32%), and that of MLT type showed DEHP (34%)>tebufenozide (31%)>BPA (25%). As the concentration of Tebufenozide increased, the incidence of light brown mentum was dose dependent. While the incidences of light brown mentum following exposure to BPA and DEHP were not associated with their concentrations.

• Korean Journal of Environment and Ecology
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• v.29 no.6
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• pp.873-883
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• 2015

From August 2012 to April 2013, the ichthyofauna and post-restoration properties of Yangjae stream were investigated. A total of 1,503 fish of 2 forms, 16 species and 5 families were studied during the survey period. A survey of the distribution of freshwater fish inhabiting Yangjae stream after restoration of the stream showed large populations of Zacco platypus and Rhynchocypris oxycephalus. From the frequency distribution of the total length for the Zacco platypus population inhabiting Yangjae stream, it was estimated that there are 4 distinct age groups, with an abundance of the 27-63 mm (Age $0^+$) category accounting for 51.3% of the population. The regression coefficient (b) for the length-weight relationship in Zacco platypus was 3.27, while the slope of the condition factor was positive, demonstrating that stable growth conditions are being maintained. Analysis of tolerance and trophic guilds showed a decrease in the numbers of sensitive species and insectivore species further downstream, and an increase in tolerant species and omnivore species. Principal component analysis using community indices and indices of biotic integrity (IBI) showed that there were differences according to the survey time: the first and second surveys showed major changes on certain single species populations while during the third survey, it was analyzed that the populations of various types of fish had established balance.

• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.865-873
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• 2016

Since 2004, Asiatic Black Bear of the Jirisan National Park is subjected to the restoration project through the re-introduction by the Maritime Province of Siberia in Russia, North Korea, Northeastern part of China and Seoul Grand Park. The purpose of this study is to analyze diets with scat to identify Asiatic Black Bear's feeding habit and eating resources environment in the Jirisan National Park. 78 scats of Asiatic Black Bears were observed during the field studies of radio telemetry-marked bears and by chance in the Jrisan National Park, from 2005 to 2013. The relative frequency of occurrence demonstrated that the plants comprised the highest with 77%, followed by insects with 12.8%, mammals with 5.6%, birds with 0.5%, arthropoda with 0.5%, and others with 3.6%. Also, 52 scats among the collected scats that were measured for the ratio of food were subjected to dry weight, and plants were the highest with 91.2%, followed by mammals with 3.6%, insects with 1.0% and others with 4.2% in the order mentioned. Asiatic Black Bear's feed research demonstrated that the Asiatic Black Bear at Jirisan is omnivorous and that the vegetable food is the main feed instead of animal feed.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.446-451
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• 2017

The length frequency and weight-length relationships within the loach population of Misgurnus anguillicaudatus were investigated in environment-friendly (EFP) and conventional paddy fields (CP) in South Korea, in order to identify the influences of farming practices to the loach population living in paddy ecosystem. The size-frequency of distribution of M. anguillicaudatus populations noted to differ significantly when the loach populations of the EFP and the CP were compared. The mean weight and length of the loach population in EFP was greater than those of the loaches in CP. The equations based on weight and total length relationship in EFP and CP were $W=0.000004L^{3.0747}$ and $W=0.000002L^{3.2106}$, respectively. The condition factor (K) against total length of loaches at two paddy field types with different farming practices indicates that the loach population in EFP(mean K=0.95) had access to better nutritional conditions than those in CP (mean K=0.67). It therefore appears that the size and structure of loach populations in rice paddy fields might be affected by farming practices.

• Korean Journal of Environmental Biology
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• v.42 no.1
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• pp.15-27
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• 2024

The goal of this study was to provide basic data necessary for managing fish in the Seomgang River by confirming diversity of fish species in the Seomgang River and determining the degree of change in fish species through a comparison with earlier related work. Growth rate, obesity level, and temporal and spatial reproductive capacities were analyzed to determine growth characteristics of dominant species. Fish fauna and structure of the fish community were surveyed at three different time points from October of 2020 to August of 2021 at eight sites. In addition, growth characteristics of Zacco platypus from June of 2021 to July of 2022 at four sites were determined. A total of 3,999 individuals, 43 species, and ten families of fish were identified. Among these species, 19 (44.19%) were Korean endemic species and four (9.30%) were endangered species. The dominant species was Z. platypus. Pungtungia herzi was identified as a subdominant species. An analysis of length-weight relationships and condition factor (k) of Z. platypus confirmed a good state of growth. As a result of a frequency analysis of the total length, the life cycle of the Z. platypus population living in the Seomgang River was found to be stable. According to gonadosomatic index (GSI) analysis, the spawning season of Z. platypus was estimated to occur after May, consistent with the literature.

• Korean Journal of Environment and Ecology
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• v.26 no.3
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• pp.333-341
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• 2012

To investigate the feeding habits of the Kaloula borealis, the stomach contents of 52 out of 56 specimens collected around Daejung-up, Jeju Island in June 2011 were studied. The stomach contents were analyzed with the stomach flushing method. According to the results, the main preys of the Kaloula borealis were Diptera sp., Harpalidae, Formicidae and Drosophilidae. the Kaloula borealis of all sizes fed on small preys, while individuals with large SVL fed on big preys. By feeding on a large amount of food with a small number of activities, the individuals with large SVL is considered to enhance energy efficiency. In many cases, the Kaloula borealis fed on Diptera sp. or Drosophilidae, which are slow but active and capable of flying. As a result, the Kaloula borealis take the sit-and-wait form of preying rather than actively searching for food. The results of this research on feeding habits of the Kaloula borealis will provide valuable resources to protect the endangered Kaloula borealis experiencing a sharp decline in their population and to prepare plans for population preservation strategies for them.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.487-490
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• 2008

Field collected larvae inside the pumpkin fruit in Jinan, Chonbuk Province were kept in the laboratory at $24{\pm}2^{\circ}C$, RH $65{\pm}5%$, and 14L:10D until they pupated and eclosed. Adults were fed with dry-milk based diet. Mating behavior was observed when they were 40 days old in a field cage at dusk in July and October, 2008. Wing vibration in male took place under the light intensity of 200 lux-20 lux, however, most commonly under 30 lux. Mounting between male and female was observed under 150 lux-30 lux after the act of wing vibration, also most frequently under 30 lux. Copulation occurred under 150 lux-20 lux. Females approached face to face to males which had been engaged in wing vibration and the copulation was successful for up to 64%. Copulation never occurred when a female positioned in front or at side of the male that was not engaged in wing vibration.

• Animal Systematics, Evolution and Diversity
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• v.11 no.2
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• pp.207-221
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• 1995

Electrophoretic analysis was performed to determine the interspecific genetic relationships of the genus Raja collected in Korea waters. We confirmed 5 species [Raja (Okamejei) meerdervoortii Bleeker, R.(O).acutispina Ishiyama, R.(O) kenojei Muller et Henle, Raja (Dipturus) kwangtungensis Chu, and R.(D.) pulchra Liu] inhabting in Korea. As results of starch gel electrophoresis, 24 genetic loci were obtained from 13 enzymic and non-enzymic proteins, and allele frequencies of each locus were calculated . Even thought their various dorsal color patterns, the mean genetic similarity among 4 conspecific populations of R.(O) kenojei showed highly close genetic relationships (S=0.966) R.(O) kenojei and R.(D) kwangtungensis which belong to different subgenus , revealed subspecific level of differentiation (S=0.829). R. (Diptuuus ) kwangtungensis was genetically much closer to Raja(Okamejei) species than to Raja (Dipturus) species group. R.(O) acutispina and R.(D) kwangtungensis were unrecorded species to Korea.

• Korean journal of applied entomology
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• v.48 no.4
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• pp.535-539
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• 2009

This study was conducted to identify plant-parasitic nematodes and determine the distribution pattern of the nematode species in citrus fruit orchards in Korea from April to August, 2008. Plant-parasitic nematodes were found in 139 among 178 soil samples. Tylenchulus semipenetrans was collected from 85 out of 94 Citrus unshiu orchards examined (90.4%). C. junos orchards infested with T. semipenetrans were 60 out of 84 (71.4%). However, proportion of dominant species between the two was different. At domestic Citrus orchards, it proved that T. semipenetrans was the most important plant-parasitic nematode from this study. The overall frequency of the plant-parasitic nematodes was positively correlated with the cultivation years. More alkaline soils tended to harbor more T. semipenetrans. However the correlation coefficient between the two was very low.

• Korean Journal of Ichthyology
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• v.28 no.1
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• pp.41-46
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• 2016

The feeding habits of juvenile (14.0~29.0 mm SL) of Gymnogobius heptacanthus were examined based on 229 individuals, that collected from June to August 2011 in the coastal water of Geoje, Korea. G. heptacanthus fed mainly on copepods which constituted 96.74% in IRI. Barnacle larvae were the second largest dietary component. Its diet also included small quantities of tintinnids, cladocerans and decapods. Graphical analysis of the diet composition showed that G. heptacanthus is a specialized predator characterized by strong individual feeding specialization. Especially copepods were heavily selected by of juvenile G. heptacanthus regardless of prey availability.