There are many modifications of eye shape and structure among fish, the general plan is similar throughout. This study was performed to comparative investigation for the lens shape and the interlocking pattern of lens fiber in genus Zacco (Z. temmincki and Z. platypus) and Pseudogobio (P. esocinus). The equatorial and axis diameter of lens for the classification of lens shape were measured by micrometer. And the interlocking patterns of lens fibers were observed by scanning electron microscopy (SEM). The lens shapes of Z. platypus and Z. temmincki were spherical (axis /equqtorial diameter = 1), but the lens shape of P. esocinus was subspherical type (axis / equqtorial diameter = 0.87). The interlocking patterns of lens fibers showed that Z. temmincki have an "anchor and socket" connection, Z. platy-pus have a "ball and socket" connection, and P. esocinus have a "rod and socket" connection. The results of this study may be utilized in the taxonomic keys for the classification of fish.
Axis, Cervical Vertebra ; Classification ; Microscopy, Electron, Scanning ; Platypus

The Hongcheon river system flows down through the Hongcheon area of Kangwon-do, and reaches to the Cheongpyeong Dam in Kyonggi-do. Stool specimens from the inhabitants residing along the Hongcheon river basin were examined to detect infection rate of Metagonimus sp., and the intermediate hosts were collected to detect larval stages. The results obtained were as follows: Thirty-nine (33 males and 6 females) out of 529 (314 males and 215 females) inhabitants were infected with Metagonimus sp., showing a total positive rate of 7.4 per cent. In eight areas surveyed, the specimens from Kulji-ri of Bukbang-myon at the middle part of the river showed the highest positive rate of 26.9 per cent (14 positives out of 52) (males; 38.2per cent). The specimens from Mogog-ri of Seo-myon at the downstream of the river showed a positive rate of 10.4 per cent (13 positives out of 125) (males;12.6 per cent). The positive rates in other regions were less than 10 per cent. The density of the first intermediate host, Semisulcospira sp., was the highest in Kulji-ri of Bukbang-myon (10-20 snails per m(2)), and the infection rate of Metagonimus cercariae in the snails was 10.7 per cent(13 positives out of 121 snails). The infection rate of Metagonimus metacercariae in Zacco platypus, the fresh water fish favorably eaten raw by the inhabitants, was 68.2 per cent (30 positives out of 44 fishes), and most metacercariae were detected under the scales (89.9 per cent). Adult flukes were obtained from the small intestine of a rat, 15 days after infection with the metacercariae obtained from Z. platypus. These adult flukes were identified to be the same srecies as those obtained from human hosts. By this survey, new endemic areas of Metagonimus infection were discovered along the Hongcheon river basin and the main source of infection was the fresh water fish, Z. platypus.
parasitology-helminth-termatoda ; Metagonimus sp. ; epidemiology ; metacercaria ; Zacco platypus

This study was performed to investigate whether the kinds and arrangement patterns of the cone cells were related to the kinds of behavior, prey and habitat in the species of genus Zacco and genus Pseudogobio The retinas were observed by a light microscopy using H-E staining method. The cone cells of Z. platypus and Z. temmincki showed compact mosaic patterns of row type. Keep apart from the center, the diameters of the double and single cone cells were gradually increased. Z. temmincki developed the identical double cone cells, and Z. platypus developed the non-identical double and single cone cells. But, Pseudogobio esocinus constituted loose mosaic patterns of row and irregular types and developed the identical double cones and single cone cells. The above results suggest that the kinds and mosaic pattern of cone cells of Z. temmincki feeding on a moving aquatic insects in relative limpid water and swift current, reflect the highest resolution among these three species. And the kinds and mosaic pattern of cone cells of P. esocinus keep watching around in the sand ground and feeding on a moving aquatic insects in relative limpid water and gentle current, suggest that if has better resolution than those of Z. platypus feeding on mainly adhesive algae and some aquatic insects in slightly turbid water.
Adhesives ; Ecosystem* ; Insects ; Microscopy ; Platypus ; Retina ; Retinaldehyde* ; Silicon Dioxide ; Water

The author studied the infection rates of Clonorchiis sinensis in the inhabitants of Kyungpook Province, and surveyed infestation rates of Clonorchis metacercarias in the twelve kinds of fresh water fishes for the purpose of the eradication. plan of clonorchiasis of Kyungpook Province. The examination was continued from April 1960 to October 1962 with 24,252 inhabitants ranging from four months to over sixty aged. All the family were tested intradermally with Clonorchis antigen and then confirmed the eggs by M.G.L. technique. The results of the examination were summarized as follows. I. The infection rate of the inhabitants; In the people tested, 27.7 percent was infected with Clonorchis sinensis. There were no remarkable differences in the infection rates among each Districts; River side inhabitants(Yungchun-Gun 23.6 percent, Andong-Gun 27.4 percent), paddy field inhabitants(Yungchun- Gun 23.6 percent, Sangchu-Gun 29.1 percent) and mountain side inhabitants (Chungsong-Gun 23.8 percent, Yungyang-Gun 27.7%). However, the infection rates of the river side peoples were slightly higher than that of the districts far from the river. The infection rate of the male was 34.98 percent (4 ,628 out of 12,230), while the female was 18.96 percent (2090 out of 11022). The maximum infection rate of the male group was observed in the 35-39 age group (73.8 %) and in female, 55-59 age group (34.l percent) respectively, however it was gradually decreased in the senile group. II. The infection rates of the family group; Those infected in both husband and wife were 28 percent(357 out of 1,289), husband only was 52 percent (672 out of 1,289) and wife only was 4 percent (50 out of 1,289). The children of the infected parents revealed higher morbidity than that of the non-infected parents. The children of the infected father revealed much morbidity than that of the mother's side. On the contrary, children's morbidity rate of the infected widow was higher than that of the widower. III. The infestation rates of fresh water fishes; The metacercaria of Clonorchis sinensis was found in the flesh exclusive of the Misgurnus anguillicaudatus and Zacco platypus in the 11 kinds of fresh water fishes. The maximum infestation rate of 55.8 percent was revealed at Pseudorasbora parva and next to it was Sarcocheilichthys wakiyae of 5l.7 percent. The number of metacercaria in flesh was decreased as compared to the previously examined level.
parasitology-helminth-trematoda-Clonorchis sinensis ; epidemiology ; Misgurnus anguillicaudatus ; Zacco platypus ; Sarcocheilichthys wakiyae ; Pseudorasbora parva

The infection status of Clonorchis sinensis metacercariae (CsMc) was examined in freshwater fish from a highly prevalent site, Wicheon (a branch of Nakdong-gang), which is located in Gunwi-gun, Gyeongsangbuk-do, the Republic of Korea. Total 1,162 fish in 32 species were examined by the artificial digestion method through 6 years. CsMc were detected in 720 (67.5%) out of 1,067 fish (26 spp.) and their density was 610 per fish infected. In the susceptible gobioninid fish group, i.e., Pungtungia herzi, Squalidus gracilis majimae, Squalidus japonicus coreanus, Sarcocheilichthys variegatus wakiyae and Pseudorasbora parva, all of 323 fish were infected with an average of 1,310 CsMc. Total 23 (95.8%) gobioninid fish, i.e., Pseudogobio esocinus, Abbottina springeri, Hemibarbus longirostris, Microphysogobio koreensis, and Microphysogobio jeoni, were infected with 127 CsMc in average. In the acheilognathinid fish (bitterlings) group, the prevalence was 77.0%, and the density was 50 CsMc per fish infected. In the rasborinid fish (chubs) group, i.e., Zacco platypus, Zacco temminckii, Zacco koreanus, and Opsariichthys uncirostris amurensis, 147 (36.5%) out of 403 fish examined were infected with 15 CsMc in average. The susceptibility indices of CsMc were 412 in the overall positive fish group, 1,310 in the gobioninid group-1, 122 in the gobioninid group-2, 38.5 in the acheilognathinid group, and 5.5 in the rasborinid fish group. Conclusively, it was confirmed that CsMc are highly prevalent in fish from Wicheon, and their infection tendency varied according to the subfamily groups in Cyprinidae fish hosts.
Clonorchis sinensis ; Cyprinidae ; Digestion ; Fresh Water ; Gyeongsangbuk-do ; Korea ; Metacercariae ; Methods ; Platypus ; Prevalence ; Republic of Korea ; Rivers

The ambrosia beetle, Platypus koryoensis, is a serious pest of oak trees in Korea. In this study we investigated filamentous fungi present in the body of the beetle. Fourteen genera of filamentous fungi belonging to Ascomycota and Basidiomycota were isolated. Among the isolated fungi, some were able to produce wood degrading enzymes. This is first report of fungi associated with P. koryoensis.
Ambrosia ; Ascomycota ; Basidiomycota ; Beetles ; Fungi ; Insect Vectors ; Insects ; Korea ; Platypus ; Quercus ; Wood

The ambrosia beetle, Platypus koryoensis, is an economically important pest affecting oak trees in Korea. Candida kashinagacola was isolated from galleries of the beetle in oak wood and identified by analyses of morphology, physiological properties, and nucleotide sequence of the large subunit ribosomal DNA. This is the first report on Candida species associated with oak wilt disease vectored by the ambrosia beetle, Platypus koryoensis, in Korea.
Ambrosia ; Base Sequence ; Beetles ; Candida* ; Disease Vectors* ; DNA, Ribosomal ; Korea* ; Platypus* ; Quercus ; Wood

The infection status with Clonorchis sinensis metacercariae (CsMc) was examined in freshwater fishes from Yangcheon (a branch of Gyeongho-gang), which is located in Sancheong-gun, Gyeongsangnam-do, the Republic of Korea. Total 2,201 fishes in 26 species were examined by the artificial digestion method through 7 years. CsMc were detected in 1,171 (53.2%) fishes in 21 spp. (80.8%) and their density was 85 per fish infected. Total 532 (99.6%) out of 534 Pungtungia herzi (index fish) examined were infected with 147 CsMc per fish infected. Metacercarial densities in this fish were highest in 2015 (179 CsMc), followed by 2012 (168), 2013 (152), 2016 (145), 2014 (114), and 2017 (89) respectively. In the gobioninid fish group, i.e., P. herzi, Sarcocheilichthys spp., Squalidus spp., Pseudogobio esocinus, Hemibarbus longirostris, and Hemibarbus labeo, 841 (92.7%) fishes were infected with 117 CsMc per fish infected. Total 250 (54.7%) acheilognathinid fish (bitterlings), Acheilognathus spp. and Acanthorhodeus spp. were infected with 5.8 CsMc. In the rasborinid fish (chubs) group, i.e., Zacco platypus, Zacco temminckii, and Zacco koreanus, 77 (13.7%) out of 563 fish examined were infected with 2.4 CsMc in average. The susceptibility indices of CsMc were 49.09 in the overall positive fish group, 104.15 in the gobioninid group, 3.17 in the acheilognathinid group and 0.35 in the rasborinid fish group respectively. Only 1 CsMc was detected in 3 fish species, Coreoperca herzi, Channa argus, and Lepomis macrochirus, respectively. Conclusively, it was confirmed that CsMc are moderately prevalent in fishes from Yangcheon in Sancheon-gun, Gyeongsangnam-do, Korea.
Clonorchis sinensis ; Cyprinidae ; Digestion ; Fishes ; Fresh Water ; Gyeongsangnam-do ; Korea ; Metacercariae ; Methods ; Platypus ; Republic of Korea

The prevalences of the fluke belonging to genus Metagonimus have been reported along the upper stream of inhabitants by several workers since 1980, however the taxonomical problems of the fluke was not yet settled. The larval flukes; cercaria and metacercaria as well as their intermediate hosts, and adult were studied in order to identify the Metagonimus in the areas. The results obtained are summarized as follows: The snails, Semisulcospira globus were collected from the three different localities along the upper stream of the River. The cercariae were found from 125(7.2%) out of 1,730 snails by natural emerging method, and were identified into 5 species including Metagonimus sp. (3.7%), Pseudexorchis major(1.4%), Cercaria nipponensis (0.9), Cercaria incerta (0.6%) and Cercaria yoshidae(0.6%). Cercariae of Metagonimus species had four to five oral spines on its anterior of the first line. The cercariae of Metagonimus were experimentally exposed to goldfish. Infection rate was 22.9% out of 105 goldfish, and the encysted metacercariae were found in fins(86.7%) and on scales (13.7%) of the fishes, but not in their muscle, head or visceral organs. Seven species of fish were caught in the Daecheong reservoir and the upper stream. Infestations with metacercaria of Metagonimus were found 100% in Opsariichtys bidens and the parasitized numbers of the metacercariae were observed from 250 to 2,400 per fish. In the upper stream, Zacco temmincki, Z. platypus and Pseudogobio esocinus were infected 100% with the metacercaria, on the other hand, the fishes caught in the reservoir showed the lower infestation rates, and a few metacercariae found in the fishes Carassius carassius and Cyprinus carpio in the reservoir and the stream. The majority of metacercariae was detected only on the scales of fishes. In order to know the infectivity and the distribution patterns in the intestine of hosts, rats and dogs were infected with the metacercariae obtained from O. bidens and Z. platypus. In addition the metacercariae obtained from Z. temmincki, P. esocinus and goldfish were given to the rats. The recovery rates of the worms in the small intestine of dogs were higher (63.3-65.8%) than those of the rats (3.5-31.6%). The flukes were found mostly in the middle and the lower part of small tntestine of the rats and the dogs, but no worm was collected in the upper part of the intestine of rats. The size of adult flukes varied by the hosts. In the adult flukes, oral sucker was smaller than ventral sucker, and the right and left testes were located diagonally, the uterine tubules circled around the upper left testis. The average egg size was 29.1 x 17.7 micro-meter. According to the above results, the flukes belonging to genus Metagonimus distributed along the Geum River was concluded to be identical with Miyata type of M. yokogawai as that Saito had proposed.
parasitology-helminth-trematoda ; Metagonimus sp. ; epidemiology ; cercaria ; metacercaria ; Zacco temmincki ; Zacco platypus ; Pseudogobio esocinus ; Opsariichtys bidens ; Carassius carassius ; Cyprinus carpio

The infection status of Centrocestus armatus metacercariae (CaMc) was broadly surveyed in freshwater fishes from major river systems in the Republic of Korea (Korea) during 2008–2017. A total of 14,977 fishes was caught and examined by the artificial digestion method. CaMc were detected in 3,818 (97.1%) (2,114 Z. platypus: 96.1% and 1,704 Z. temminckii: 98.4%) out of 3,932 Zacco spp. examined and their density was 1,867 (2,109 in Z. platypus and 1,567 in Z. temminckii) per fish infected. The prevalences with CaMc were high, 93.7–100%, in Zacco spp. from all surveyed areas. However, their densities were more or less different by the surveyed areas and fish species. They were most high in Nakdong-gang in Gyeongsangnam-do (4,201 in average), and followed by Geum-gang (2,343), Nakdong-gang in Gyeongsangbuk-do (1,623), Han-gang (1,564), Tamjin-gang and Yeongsan-gang (1,540), streams in the east coast (1,028), Seomjin-gang (488) and Mangyeong-gang (170). In another species of rasborinid fish, Opsariichthys uncirostris amurensis, CaMc were detected in 222 (74.8%) out of 297 ones examined and their density was 278 (1–4,480) per fish infected. CaMc were also detected in total 41 fish species except for the rasborinid fish, Z. platypus, Z. temminckii and O. uncirostris amurensis. Conclusively, it was confirmed that among the 3 species of rasborinid fish, Z. platypus and Z. temminckii are highly prevalent and O. uncirostris amurensis is moderately prevalent with CaMc. Additionally, we could know that variety of fish species act as the second intermediate hosts of C. armatus in Korea.
Digestion ; Fishes ; Fresh Water ; Gyeongsangbuk-do ; Gyeongsangnam-do ; Korea ; Metacercariae ; Methods ; Platypus ; Prevalence ; Republic of Korea ; Rivers ; Water