• Korean Journal of Ichthyology
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• v.24 no.1
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• pp.27-34
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• 2012

Population ecology of $Acheilognathus$ $macropterus$ was investigated at the part of the Bulgapcheon stream in Korea from March to November in 2006 and April in 2008. It mainly inhabited in slow water with sand and mud bottoms. The standard length of this population indicated that below 48 mm group is one year old, 48~58mm group is two years old, 58~64mm group is three years old and longer than 66 mm group is regarded over four years old. The sex ratio of the female to the male was 1:0.99. Spawning season from April to June with the water temperature in $15{\sim}20^{\circ}C$. The average number of eggs in ovary was $680{\pm}209$. The matured egg size was $1.92{\times}1.60mm$. Stomach contents were mainly phytoplanktons such as the genera Navicular, Cymbella, Fragilaria.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.3
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• pp.248-253
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• 2018

Freshwater farms are primarily located adjacent to rivers and lakes, facilitating the introduction and spread of pathogens into natural systems. Therefore, it is necessary to continuously monitor natural aquatic organisms, the breeding environment, and infection rates by pathogenic organisms. Fish and crustaceans were sampled 4 times in the Geum River estuary in 2016. The samples were analyzed for the presence of pathogens for reportable communicable diseases, including KHVD (koi herpesvirus disease), SVC (spring viraemia of carp), EUS (epizootic ulcerative syndrome) and WSD (white spot disease); parasite abundance was also examined. The dominant fish species were deep body bitterling Acanthorhodes macropterus (21.4%), followed by skygager Erythroculter erythropterus (12.7%). For crustaceans, Palaemon paucidens and Chinese mitten crab Eriocheir sinensis were dominant. Sixty fish and 36 crustacean species were examined for reportable communicable diseases. When using a specific primer set for each disease, PCR analysis did not detect any reportable communicable diseases in the samples. Some instances of Dactylogyrus, copepods, nematodes and metacercaria were detected. However, the PCR results indicated that the metacercaria were not Clonorchis sinensis.