• Parasites, Hosts and Diseases
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• v.23 no.2
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• pp.221-229
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• 1985

The echinostomatid metacercariae encysted in the gill of the fresh water fish, Pseudorasbora larva were identified through obtaining adult worms after eBperimental infection to mice. In addition, a brief course of worm development and maturation was observed in this experimental host. The results were as follows: 1. The echinostomatid metacercariae were elliptical, golden yellow, 0.073∼0.078 mm long and 0.0541∼0.065 mm wide. Their head portions were characterized by the presence of a head crown armed with collar spines of total 24 in number and interrupted at the mid-dorsal side of the oral sucker. 2. The average rate of worm recovery froth 12 mice (on the 1-2lth postinfection days) was 19.4 % and the rate revealed no decrease in accordance with the increase of infection duration. The worms were collected chiefly from the lower part of the small intestine. 3. After the infection, their sexual maturation was attained in 5 days and their growth in size nearly completed in 7 days. The early growth curve of genital organs was S shape while that of nongenital organs was C form. In 5 day old worms, 1 or 2 eggs were found from their uteri and the stools of mice revealed echinostomatid eggs from the 5-6th postinfection day. 4. The 7 day old adult worms were ovoid in shape, 0.54-0.69 mm long and 0.29-0.34 mm wide, and characterized by a well developed head crown with 24 collar spines and vitelline follicles distributed from the acetabular level down to the posterior end of body. Based on these characters they were identified to be Echinochasmus japonicus Tanabe, 1926. From these results, it is verified that p. larva is one of the second intermediate hosts of 5. jatonicus in Korea.

• Korean Journal of Ichthyology
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• v.22 no.4
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• pp.238-248
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• 2010

We performed field investigations at six stations in Buk Stream of Goseong-gun, Gangwon-do, Korea, from May to September 2009 to understand the stream's fish fauna and community structure. In the survey, 31 species belonging to 20 families were collected. Dominant species by number was Zacoo koreanus (30.0%), and subdominant species were Pungitius kaibarae (9.4%) and Rhynchocypris steindachneri (9.3%). In biomass, the dominant species was Tribolodon hakonensis (35.5%), and subdominant species were Z. koreanus (22.5%) and Cobitis pacifica (7.5%). Eight Korean endemic fish species and two endangered species (P. kaibarae and Pungitius sinensis) were collected. In addition, four anadromous fish species (T. hakonensis, Oncorhynchus masou masou, O. keta, Gasterosteus aculeatus) and two amphidromus fish species (Plecoglossus altivelis altivelis and Gymnogobius urotaenia) were observed. Interestingly, we verified the existence of several fish species in Buk Stream where they have not lived before. Those species were previously reported to live only in rivers that run into the western and southern sea of Korea. Five of those species (Zacoo koreanus, Z. platypus, Silurus microdorsalis, Liobagrus andersoni and Coreoperca herzi) were reported in Buk Stream in the 1980s. The other species (Pungtungia herzi, Pseudorasbora parva, Squalidus multimaculatus, Misgurnus mizolepis, Koreocobitis rotundicaudata, Silurus asotus and Odontobutis interrupta) have been introduced since the 1990s.

• Journal of Ecology and Environment
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• v.35 no.1
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• pp.9-14
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• 2012

Yellow bitterns (Ixobrychus sinensis) are a small wetland bird common to Asian countries including South Korea, Japan, and China. The aim of this study is to describe diet of yellow bitterns during the breeding season in artificial wetland of northeastern South Korea between May to August 1999-2001. For the purposes of this paper, we observe the frequency of nest visiting by parents during the chick rearing period. A total of 98 boluses regurgitated by 52 chicks aged 1 day to 11 days after hatching form the sample and are shown to contain 323 food items. A bolus contained mean 3.8 items and weighs 0.2 g to 7.7 g. The most regularly occurring food items recorded are fish (63%) and insets (33%). In terms of fish, top mouth minnows (Pseudorasbora parva) and crucian carps (Carassius auratus) are frequently observed. In terms of insects, there are mosquitoes (Diptera), instars of dragonfly (Libelluidae), damselflies (Coenagrinonidae) and water bugs (Diplonychus japonicus). Yellow bitterns were also shown to feed on bull frogs (Rana catesbeiana), shrimp (Palaemonidae), and spiders (Araneae). The size of fish in a bolus ranged from 15.56 mm to 93.73 mm (mean, 37.08 mm). The amount of food can be observed to increase with the age of chicks (r = 0.279, P = 0.025, N = 64) but parents did not provide larger fish as chicks grew. Parent birds visited nests more frequently when they have a larger brood ($F_{1,21}$ = 14.529, P = 0.001). Our results suggest that fish is the most important prey during the breeding season and that age of chicks is related to amount of diet in yellow bitterns.

• Parasites, Hosts and Diseases
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• v.56 no.1
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• pp.41-48
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• 2018

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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.5
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• pp.363-370
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• 2008

The ichthyofauna of certain reservoirs in Pohang-si, Gyeongsangbuk-do, were studied during the period from October 7-19, 2005. During the study period, 9,480 individuals (ind.) belonging to 22 species, 17 genera, 8 families and 4 orders were collected. Of these, 11 species were cyprinidae fishes, and the dominant species was Pseudorasbora parva (relative abundance 47.14%). There were six Korean endemic species (289 ind., relative abundance 3.04%), including Squalidus chankaensis tsuchigae, Squalidus mulimaculatus, Hemiculter eigenmanni, Iksookimia yongdokensis and Coreoperca herzi, and the dominant Korean endemic species was Pseudobagrus brevicorpus (relative abundance 3.04%) collected in Hoehakji, Cheonggyeji, Ahnsimji and Mabukji. There were five introduced species. Three species, including Hemiculter eigenmanni, Pseudobagrus fulvidraco and Hypomesus nipponensis, were introduced from other native stream systems, and two species, including Carassius cuvieri and Lepomis macrochirus, originated in foreign countries. Of these, Lepomis macrochirus (l,521 ind., relative abundance 16.05%) was collected at the all reservoirs except at Gidongji. These results suggest that the exotic fishes in question have been widely dispersed within the reservoirs in Pohang-si.

• Korean Journal of Environment and Ecology
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• v.29 no.3
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• pp.401-409
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• 2015

The fish community and introduced fish were surveyed at eight stations of Lake Soyang from March to October, 2013. A total of 41 species of twelve families were collected from the survey stations and among them, two species: Hemibarbus mylodon and Siniperca scherzeri (albino type) were identified as natural monument. There were fifteen Korean endemic species (36.6 %) including Acheilognathus yamatsutae. When compared with previous data (2003), A. yamatsutae, Pseudorasbora parva, Sarcocheilichthys nigripinnis morii, Sarcocheilichthys variegatus wakiyae, Orthrias nudus, Leiocassisuss ussuriensis, Oncorhynchus mykiss, and Micropterus salmoides appeared new in the lake. Dominant species were Hypomesus olidus (St. 1, 3, 6, 7, 8), Lepomis macrochirus (St. 2, 4) and Zacco platypus (St. 5). Of the 12 introduced species fishes in Lake Soyang, Anguilla japonica, Hemiculter eigenmanni, H. nipponensis, Rhinogobius giurinus and Tridentiger brevispinis were introduced and released from other native river water zones in Korea but Cyprinus carpio (Israeli type), Carassius cuvieri, O. mykiss, Ictalurus puntatus, L. macrochirus, and M. salmoides originated from foreign countries.

• Korean Journal of Environment and Ecology
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• v.29 no.1
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• pp.29-45
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• 2015

Water chemistry and fish community, based on fish compositions and ecological characteristics(trophic/tolerance guilds and condition factor), were compared in Gucheon Reservoir($G_cR$) and Yeoncho Reservoir($Y_cR$). Chemical parameters of water quality such as BOD, COD, nutrient(N, P) and suspended solids indicated that water quality was better in the $Y_cR$ than $G_cR$, and the temporal variability in seasonal and interannual patterns were greater in the $Y_cR$. The greater variability was mainly attributed to intense dilutions of reservoir water by Asian monsoon rain during July-August. Fish guild analysis indicated that species diversity was higher in the $G_cR$ than the $Y_cR$, and that the proportion of tolerant and omnivore species were greater in the $Y_cR$. Regression analysis of body weight-total length showed that the regression coefficient(b value) was lower in the $G_cR$(2.15 ~ 2.40) than the $Y_cR$(2.59 ~ 3.14). Condition factor(K) of fish against the total length showed negative slope of Zacco temminckii, Carassius auratus, Pseudorasbora parva and Rhinogobius brunneus population in the $G_cR$, and a positive slope of Carassius auratus and Rhinogobius brunneus population in $Y_cR$. Overall, our data suggest that the growth of the fish populations, based on the length-weight relations and condition factor, reflected the trophic regime of nutrients and organic matter.

• Parasites, Hosts and Diseases
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• v.57 no.6
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• pp.681-690
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• 2019

The infection status of digenetic trematode metacercariae (DTM) was investigated in fishes from coastal lakes in Gangwon-do, the Republic of Korea (Korea). All fishes collected in 5 lakes were examined with the artificial digestion method. More than 10 species, i.e., Metagonimus spp., Pygidiopsis summa, Centrocestus armatus, Metorchis orientalis, M. taiwanensis, Clinostomum complanatum, Echinostoma spp., Stictodora spp., Diplostomum sp. and Diplostomid No. 1. by Morita (1960), of DTM were detected in fishes from 5 coastal lakes in Gangwon-do. Metagonimus spp. metacercariae were found in 52 (41.3%) out of 126 sea rundace, Tribolodon hakonensis, from 5 lakes, and their density was 14.6 per fish infected. P. summa metacercariae were detected in 48 (84.2%) out of 57 mullets from 5 lakes, and their density was 316 per fish infected. C. armatus metacercariae were detected in 7 (14.6%) T. hakonensis and 3 (15.0%) Tridentiger brevispinis from Hyang-ho, and 5 (19.2%) Acanthogobius flavimanus from Gyeongpo-ho. Stictodora spp. metacercariae were found in 4 fish species, i.e., Tridentiger obscurus, Tridentiger trigonocephalus, Chelon haematocheilus, and Acanthogobius lactipes, from Gyeongpo-ho. Total 15 C. complanatum metacercariae were detected in 2 (9.1%) crucian carp, Carassius auratus, from Songji-ho. M. taiwanensis metacercariae were found in T. hakonensis from Hyang-ho and Gyeongpo-ho and in Pseudorasbora parva from Gyeongpo-ho. Total 11 M. orientalis metacercariae were detected in 3 (6.3%) T. hakonensis from Hyang-ho. From the above results, it was confirmed that various species of DTM are infected in fishes from coastal lakes in Gangwon-do, Korea.

• Korean Journal of Ichthyology
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• v.19 no.4
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• pp.371-377
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• 2007

The passive integrated transponder (PIT) telemetry is a useful method for investigating fish population dynamics, community structure and migration. It can be applied for small fishes (TL<100 mm) because of its tiny size and light weight. The survival rate of PIT tag was investigated on 4 small size cyprindae fish species, Carassius gibelio langsdorfi (n=34, standard length; $91.9{\pm}0.9mm$, body weight; $21.2{\pm}0.9g$), Hypophthalmichthys molitrix (n=16, SL; $75.1{\pm}0.9mm$, BW; $6.0{\pm}0.2g$), Pseudorasbora parva (n=30, SL; $51.4{\pm}1.1mm$, BW; $2.7{\pm}0.2g$) and Phoxinus phoxinus (n=37, SL; $70.6{\pm}1.4mm$, BW; $8.2{\pm}0.5g$) under age 1 for applicability and effectiveness. We used three type tags including a small (length 11.0 mm, diameter 2.1 mm, weight 0.088 g), middle (20 mm, 3.5 mm, 0.102 g), large (30 mm, 3.5 mm, 0.298 g) size. After 30 days of tag insertion, survival rate of 117 individuals were 58.1% (large tag, 50.0%; middle tag, 57.5%; small tag, 61.4%). Survival rates varied between three types of tags because the abdominal cavity of each individual was different size. The death was due to surgical damage. If we apply tagging systems on field research of the Korean freshwater fish, the PIT tag will be effective method for analyzing fish ecology.

• Korean Journal of Environmental Biology
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• v.36 no.1
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• pp.73-81
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• 2018

This study was conducted to understand the current status of the translocated species using a precede study and a model to evaluate the potential invasiveness that could adversely affect the aquatic ecosystem in the Gangneungnamdae Stream. A total of 12 translocated species were investigated and identified from 9 sites in a precede study, and steadily increased since 1982. For the study, which utilized research based on the total FISK (Fish Invasivenss Screening Kit) scores, all of the non-native fishes in Gangneungnamdae Stream were classified into two groups: namely as a high and a medium risk of becoming invasive. It was determined that there were two species (Zacco platypus and Pseudorasbora parva) that were determined to have posed the highest risk. The study determined that the mean scores were shown to have ranged from $3.06({\pm}0.16)-3.42({\pm}0.13)$. Consequently, the habitat analysis showed that the determined QHEI (Qualitative Habitat Evaluation Index) values in the stream averaged 146 (88-171), indicating that an optimal habitat condition did exist in that locale. It can be inferred that compared to land use in the surrounding watersheds, the QHEI values and frequency of translocated species showed the lower the altitude of stream, the QHEI values were decreased and in case of land use pattern, a noted decreased forest and grassland area, and gradually increased urbanized area was seen to exist in the region. The correlation between the fish assemblage, QHEI, land use pattern of surrounding watershed and number of translocated species was identified and analyzed when the stream altitude decreased, and the number of species was increased (r= - 0.782, p=0.0127), the number of species was decreased (r= - 0.737, p=0.0234), and finally when the QHEI values were decreased, it was noted that the urbanized area was increased (r=0.292, p=0.446). In the case of the number of translocated species, when the number of translocated species was increased, the associated urbanized area was increased.