• Parasites, Hosts and Diseases
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• v.54 no.1
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• pp.109-112
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• 2016

We performed a molecular genetic study on the sequences of 18S ribosomal RNA (ITS1 region) gene in 4-day-old adult worms of Macroorchis spinulosus recovered in mice experimentally infected with metacercariae from crayfish in Jeollanam-do Province, Korea. The metacercariae were round, $180{\mu}m$ in average diameter, encysted with 2 layers of thick walls, but the stylet on the oral sucker was not clearly seen. The adult flukes were oval shape, and $760-820{\mu}m$ long and $320-450{\mu}m$ wide, with anterolateral location of 2 large testes. The phylogenetic tree based on ITS1 sequences of 6 M. spinulosus samples showed their distinguished position from other trematode species in GenBank. The most closely resembled group was Paragonimus spp. which also take crayfish or crabs as the second intermediate host. The present study is the first molecular characterization of M. spinulosus and provided a basis for further phylogenetic studies to compare with other trematode fauna in Korea.

• Journal of Animal Science and Technology
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• v.56 no.5
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• pp.16.1-16.9
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• 2014

Fatty acids (FA) have recently been used in several studies to infer the diet in a number of species. While these studies have been largely successful, most have dealt with predators that have a fairly specialized diet. In this paper, we used FA analysis as a tool to infer the diet of the nearctic river otter (Lontra canadensis). The river otter is an opportunistic predator known to subsist on a wide variety of prey including, fishes, crayfish, molluscs, reptiles and amphibians, among others. We analyzed the principle components of 60 FA from otters and 25 potential prey species in Illinois, USA. Prey species came from 4 major taxonomic divisions: fishes, crayfish, molluscs and amphibians. Within each division, most, but not all, species had significantly different profiles. Using quantitative FA signature analysis, our results suggest that, by mass, fish species are the most significant component of Illinois River otters' diet ($37.7{\pm}1.0%$). Molluscs ranked second ($32.0{\pm}0.8%$), followed by amphibians ($27.3{\pm}4.3%$), and finally, crayfish ($3.0{\pm}0.6%$). Our analysis indicates that molluscs make up a larger portion of the otter diet than previously reported. Throughout much of the Midwest there have been numerous otter reintroduction efforts, many of which appear to be successful. In regions where mollusc species are endangered, these data are essential for management agencies to better understand the potential impact of otters on these species. Our analysis further suggests that quantitative FA signature analysis can be used to infer diet even when prey species are diverse, to the extent that their FA profiles differ. Better understanding of the otter's metabolism of FA would improve inferences of diet from FA analysis.

• Journal of Aquaculture
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• v.22 no.1
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• pp.16-22
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• 2009

Life history of Korean crayfishes Cambaroides similis (Koelbel) was studied 8 month from March to October, 2006 from the Gwanak mountain, Seoul, South Korea. By capture and recapture method, 551 crayfishes were collected analyzed during the experimental period. Based on the distribution pattern of body lengths, the local population putatively divided into four age groups. The sex ratio of male and female was almost equal. However, their growth rates varied by water temperature. Early juveniles seen during June became adult during August. The study findings suggest that late autumn is mating season.

• Journal of agricultural medicine and community health
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• v.4 no.1
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• pp.71-80
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• 1979

Paragonimiasis is a common trematodiasis of medical importance and one of public health problems in many areas of sob thern part of Korea. During the last sixty years, several on the prevalence among the Korean population have been carried out by various investigators, although the general distribution and prevalences of paragonimiasis are now yet clearly determind. This study was undertaken to evaluate the status of human paragonimiasis in Kang Hwa Gun, Kyung gi Province, Korea by the use of intradermal screening test whih Veronal buffered saline antigen. A total number of 208 residents (male 119, female 89) of all age group in Kilgeong-Ri, Yangdo Myun, Kang Hwa Gun were examined by the intradermal test with paragonimus antigen. The infestation rate of crayfish with Paragonimus metacerearia was also examine in Konneung and Jeoungha village, Kilgeong-Ri from March 1973 to October 1978 by the interval of two to five years. 1. In the resnlt of 208 residents, Kilgeong-Ri, the positive rate showed in 29.3% in as a whole(36.1% in male, 20.2% in female). The highest positive rate showed in 10 to 19 age group(41.5%). 2. Among the residents in Kilgeong-Ri, Paragonimus eggs were detected in 11 residents by the sputum and the stool examinations without the intradermal test result. 3. The infestation rate of crayfish with Paragonimus inetacercaria was 90.6%(116 out of 128 crayfishes) in Konneung village, and 61.5%(24 out of 39) crayfishes) in Jeongha village, Kilgeng-Ri. 4. The fluctation of the infestation tate and density of crayfish with Paragonimus metacercaria was decreased by the interval of two to five years in Konneung and Jeongha village in Kilgeong-Ri.

• Parasites, Hosts and Diseases
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• v.23 no.1
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• pp.102-110
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• 1985

In order to determine the epidemiological pattern of the Paragonimus westermani, the infestation rates for the cercarial and metacer-carial larvae of digenetic trematodes in the snail and crayfish hosts, and the prevalence of Paragonimus westermani among the residents in the vicinity of the stream Namdae, Wyangpi, and Kwang, in the Ulchin county, Kyungpook Province were studied from March to October in 1984. The population density of the snails per square meter of the habitats ranged from 5 to 25, with an average of 15. Among the seven habitats, one, Ducheon, had snails infested with the cercariae of Paragonimus westermani, and the proportion of infested snails was very low, the average being 0.152 per thousand. Of six hundred and four crayfish examined, 113 or 18.7 per cent harboured the encysted larvae of Paragonimus westermani. A high infestation rate for the metacercariae in the crayfish was found in two habitats; 39.0 per cent in the Ducheon and 21. 6 per cent m the Sokwang. The prevalence of Paragonimus westermani among the residents in Ulchin county was relatively high, 25.8 per cent by the Paragonimus intradermal tests, and the difference in the rate of infection between males and females was found to be significant (t>2). The results obtained in this study indicate that endemic foci of Paragonimus westermani exist in Ulchin county and the prevalence of this lung fluke among the residents is relatively high.

• Parasites, Hosts and Diseases
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• v.34 no.1
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• pp.1-6
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• 1996

Mccroorchis spinuLosw Ando, 1918 (Digenea: Nanophyetidael is redescribed based on adult flukes recovered from experimental mice, rats and cats which were fed with metacercariae encysted in the muscle of the crayfish, Cambnroines similis. A total of 117 adult flukes were harvested from the small intestine of the experimental animals at S-21 days post-infection. The worm recovery rate was 31-37%, not significantly different among the three kinds of animals. The metacercariae were round, 0.18 mm in average diameter, encysted with two layers of thick walls, and possessing a stylets on the oral sucker and Y- shaped exc retory bladder. The adult flukes were oval, 0.66-0.71 mm long and 0.36-0.41 mm wide, and characterized by the presence of a stylet on the oral sucker, variable location of the ovary near the mid-portion of the body, bilobed seminal vesicle, and anterolateral location of two testes. These morphological features were a little different from the original description, hence, an emended version of M. spinulosw was given. M. spinuLosw is a new intestinal trematode of animals and possibly man in Korea.

• Journal of agricultural medicine and community health
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• v.6 no.1
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• pp.5-12
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• 1981

Paragonimus infection is prevalent in Korea, establishing several endemic foci. Kim(1969) reported an endemic area in Hyeonbuk Myeon. Yangyang-Gun, but thereafter no further epidemiologic study of Paragonimus infection was performed in the Gangweon-Do. Hoengseong-Gun is mountainous area which is located in the southwestern part of Gangweon-Do and borders with Hongcheon-Gun on the east, with Pyeongchang-Gun on the east, with Yeongweol-Gun and Weonseong-Gun on the south, and with Yangpyeong-Gun on west. The author carried out an epidemiologic study of Paragonimus infection by intradermal test with V.B.S antigen, and of intermediate host (crayfish) in Hoengseong-Gun, Gangweon-Do. The results are summarized as follows: 1. The positive skin test reaction to Paragonimus antigen was 14.5% from 2,807 examiness; 16.0% in male and 11.6% in female and no sex or age difference on the skin test positive reactions was noticed among the villages. 2. The positive skin test reactions were 31.3% in Gapcheon-Myeon, 20.5% in Cheongil-Myeon and 19.8% in Woocheon-Myeon. Primary school children in Byeongjibang-ri, Gapcheon-Myeon showed positive in 36.4%. 3. The prevalence by skin test reaction by social strata was 16.1% (226 out of 1,408) in primary school children, 12.8% out of 725) in middle school, 6.4% (11 out of 172) in high school students, and 15.3% (77 out of 502) in inhabitants of Heongseong-Gun. 4. Metacercarial positives of Paragonimus in crayfish were 20.9%. Through the survey results, it is postulated that Heongseong-Gun, Gangweon-Do is to be categorized as an endemic area of Paragonimus infection.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.1
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• pp.37-50
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• 2022

The use of uncertain names for imported crustaceans causes considerable confusion for the establishment of government policies and the public market. Therefore, there have been demands for reestablishment of the domestic names of imported fish to correct the market order and to prevent damage caused by confusion among consumers. A total of 118 species of imported fisheries crustaceans were reviewed (47 crab spp., 36 shrimp spp., 27 lobster and crayfish spp., five mantis shrimp spp., and three horseshoe crab spp.). Although not belonging to the Subphylum Crustacea, three species of the Subphylum Chelicerata and five species of the Order Stomatopoda were included for review. Of these, 49 species that require Korean name assignment and reexamination of domestic names were selected and Korean names were assigned.

• Journal of Species Research
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• v.5 no.3
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• pp.459-462
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• 2016

The branchiobdellidan species Holtodrilus truncatus (Liang, 1963) is reported for the first time in Korea. The genus Holtodrilus Gelder and Brinkhurst, 1990 is monotypic within the family Xironodrilidae, and the genus and family of this species are also new to the Korean fauna. The branchiobdellidan specimens were collected from the exoskeletons of the freshwater atyid shrimp, Neocaridina sp., sampled from the 'Andeok Valley', Jeju-do Province, South Korea. Holtodrilus truncatus is characterized by its terete body form, 7/7 dental formula (with a large medial tooth and three pairs of smaller lateral teeth), and no trunk appendages. In addition, we determined a partial sequence of the mitochondrial cytochrome c oxidase subunit 1 (CO1) gene as a DNA barcode marker for H. truncatus. The present study is the first record of the branchiobdellidan occurrence on a non-crayfish host (shrimp) in Korea. To date, seven species (four genera in three families) of branchiobdellidans have been reported in the Korean fauna.

• The Korean Journal of Zoology
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• v.35 no.2
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• pp.231-239
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• 1992

For the analysis of the relative grouch of six body pans, such as carapace width. abdominal length, abdominal width, cheliped length, second pereiopod length and third pereiopod length, to the carapace length of crayfish (Comboroides similis Koelbel), the equation Y = bXa were applied. The results were as follows: 1. In the relative srourth of each body part to the carapace length, abdominal width and abdomial length in both sexes showed as positive allometrv, the third pereiopod length in both sexes as isometry and the rest shouted as negative. The least coefficient of the relative growth was found in cheliped length in female (0.9300).2. The grolwth gradient of each body part to the carapace length in each sex revealed decreasing pattern in abdominal length and third pereiopod length in both sexes and the abdominal width in male with the growth centers on the initial growth period. and the rest showed increasing pattern with the growth centers on the 6th growvth period except the abdomini,d uridth in female on the 3rd growth period.