• Korean Journal of Ichthyology
• /
• v.35 no.4
• /
• pp.270-277
• /
• 2023

Since its introduction in 1973, the bass, Micropterus salmoides, has spread to dams and rivers in Korea, adversely affecting native fish communities. In this study, after complete removal of bass from Bukchosan Reservoir, an farm reservoir that has lost its function, an attempt was made to indirectly confirm the adverse effects of bass on fish by comparing fish communities in reservoirs of a similar size where bass inhabit. The study was conducted three times a year from 2019 to 2022. As a result of the study, in Bukchosan Reservoir, where the species composition of fish was judged to be simplified due to the habitat of bass, only four species such as Carassius auratus and Rhinogobius brunneus that could be used as a food source for bass appeared before the removal of bass, but after the removal of bass. The appearance and increase of the population of the introduced small freshwater fish (Oryzias sinensis, Rhinogobius giurinus) were confirmed. When comparing Gangjeong Reservoir, Susim Reservoir, which are other reservoirs inhabited by bass investigated in this study, and Bukchosan Reservoir, this result is judged to show a trend of stabilization and recovery of fish species after removal of bass in small reservoirs with high predation pressure of bass.

• Korean Journal of Ichthyology
• /
• v.2 no.1
• /
• pp.63-76
• /
• 1990

Studies on the microdistribution, distributional aspect and affinity of Korean endemic species, SHIRl, Coreoleueiseus splendidus in th southern half of the Korean peninsula were carried out from May, 1966 to November, 1989. This species was found in 14 independent rivers and streamlets of the south Korea ; Yimjin R., Han R., Kum R., Ungchun S., Mangyung S., Dongjin R., Somjin R., Kwangyang East S., Sachun S., Gonyang S., Nakdong R., Samchukosip S., Samhwa S. of Namhae Island and Guchun S. of Geojae Islands, and were not found from Youngsan R., Ansung S. and Sabgyo S. This species was not common and independent comprising less than 25% of the total fish population in all habiting sites. Distributional zone was in the middle or upper streaches of main streams and tributaries. The average slope of distributional zone was 2.6, minimum slope was 0.29 and maximum slope was 5.56. Thirty-three species were found to occur along with this fish and 10 species of them occurred with more than 50% frequency. They were; 20 sp. of Cyprinidae, 5 sp. of Cobitidae, 1 sp. of Salmonidae, 1 sp. of Bagfridae, 1 sp. of Siluridae, 2 sp. of Amblycipitidae, of Serranidae, and 1 sp. of Eleotridae. Some species of fish appeared to have the same ecological position even though they have different distributional zones. These species were as follows; Acheilognathus signifer and A. limbata, Micriophsogobio koreensis and M. yaluensis in Cyprinidae, Cobitis koreensis, C. longicorpus, C. rotundicaudata in Cobitidae, Liobagrus andersoni and L. mediadiposalis in Amblycipitidae.

• Journal of the East Asian Society of Dietary Life
• /
• v.25 no.5
• /
• pp.791-805
• /
• 2015

Foxtail millet (Setaria italica L. Beaur) is a native Korean herbal medical food and a native millet, and Koreans have eaten it as a substitute for rice since ancient times. Foods using foxtail millet (Setaria italica L. Beaur) have been recorded not only in cookbooks but also in Korean traditional medical books several times. Therefore, the purposes of this study was to investigate Food-Therapy (食治) using foxtail millet (Setaria italica L. Beaur) recorded in the literature from 1300 to 1600 from early to mid-Joseon (朝鮮) and provide data required to develop menus for Yaksun (藥膳, herbal food). This study examined Food-Therapy using foxtail millet (Setaria italica L. Beaur) in 10 types of literatures from the 1300s to the 1600s. and is described in the literature a total of 63 times. According to classification by cooking method, porridge (粥) was most frequently mentioned in the literature at 27 times. The cooking method of Soup (湯) is described 11 times. Cooking methods such as porridge juice and soup are frequently used since those methods are digestive and absorptive. Other food ingredients described using foxtail millet (Setaria italica L. Beaur) are white leek (Allii Fistulosi Bulbus) ginger (Zingiber officinale), chicken egg, Allium chinense, sparrow (Passer montanus), rooster liver, Du-si, crucian carp (Carassius auratus L), and white broiler. Other medicinal herbs described with Setaria italica are Panax ginseng (人蔘), Poria cocos (茯笭), Angelica acutiloba (當歸), Ziziphus jujuba (大棗), Liriopeplatyphylla (麥門冬), and cinnamon (肉桂). Food-Therapy using Setaria italica L. Beauv was described as a prescription for stomach and spleen (脾胃), stomach reflux (反胃), defecation and urinary disorder (大小便難), cholera, deficiency syndrome (虛症), and tonification (補益). This focus on promoting health and preventing diseases by strengthening the stomach and spleen and improving defecation and urination using Food-Therapy when herbal medicine was rare.

• Korean Journal of Environmental Biology
• /
• v.30 no.1
• /
• pp.15-25
• /
• 2012

From April to November 2009, we performed field investigation to survey the characteristics of fish fauna and fish community structure inhabited in Yongdam reservoir in the upper Geumgang, which is changed into flat-water zone from flow-water zone by blocking the continuity by the gigantic submerged weir built in the upstream of Geumgang. 15 species belonging to 8 families were collected from natural habitat (St. 1) where its natural characteristics is well preserved, and 11 species were korean endemic fish species. 24 species belonging to 10 families were collected at the down region of Yongdam dam (St. 3), which might be affected by the change of water environment due to the dam, and 11 species were korean endemic fish species. On the other hand, 20 species belonging to 7 families were collected inside Yongdam reservoir (St. 2) which is changed into flat-water zone from flow-water zone by the dam reservoir, and 6 species were korean endemic fish species. In the dam reservoir, due to Yongdam dam built in the upper Geumgang, the original flow-water zone fish such as $Acheilognathus$ $koreensis$, $Pseudopungtungia$ $nigra$, $Coreoleuciscus$ $splendidus$, and $Gobiobotia$ $macrocephala$ were disappeared, and instead, the kinds of fish habitating in the flat-water zone tend to increase rapidly, such as $Carassius$ $auratus$, $Opsarichthys$ $uncirostris$ $amurensis$, $Hemiculter$ $eigenmanni$, $Zacco$ $platypus$, and $Lepomis$ $macrochirus$. Relative abundance of the insective fish was 66.7% at St. 1, 40.0% at St. 2, and 54.2% at St. 3. In order to preserve endemic fish species and aquatic ecosystem, it is desirable to minimize the artificial installation in the upper river, such as a large scale dam which can affect the habitat and if inevitable, it is required to prepare preservation measures when building facilities.

• Korean Journal of Ecology and Environment
• /
• v.44 no.3
• /
• pp.264-271
• /
• 2011

At the Jangheung multipurpose dam, which is on the Tamjin River, a trapping and trucking operation was established to maintain continuous upstream migration of fish,. To facilitate fish gathering, installation of an effective fishing trap was required. In this study, we evaluated the fish trap, established at the Jangheung dam, using PIT (Passive Integrated Transponder) telemetry. A total of 254 individuals from 15 species were monitored. Among these tagged species, 36 individuals from 6 species (Carassius auratus, C. cuvieri, Zacco temminckii, Z. platypus, Pungtungia herzi, and Pseudobagrus koreanus) were detected; a 14.2% detection rate. C. auratus recorded the highest detection rate of 44.2% while P. herzi was 14.3%. Z. temminckii and Z. platypus showed relatively low detection, 5% and 7.7% respectively. Some of individuals from C. auratus and Z. platypus did not pass through the antenna at the first attempt but were continuously detected on multiple days. There were no statistical differences in body size (total length, standard length and body weight) of individuals that did or did not swim into the trap (Mann-Whitney U test, p>0.05). Fish mainly swam into the trap during outflow of water from the dam (Mann-Whitney U test, p<0.001) and showed a higher detection frequency in daytime than nighttime (Mann-Whitney U test, p<0.001). Thus, for fish movement into the trap, external factors such as outflow from dam and time of day have important roles. Based on detection rate, not all fishes showed upstream migration but represented selective migration. Consequently, the establishment of flexible outflow strategies that take into consideration ecological characteristics of fishes should required for improving the efficiency of fishway.

• Korean Journal of Environmental Biology
• /
• v.19 no.4
• /
• pp.292-301
• /
• 2001

The ichthyofauna and fish community of the Gap stream water system were studied at 17 sites from March to December, 2000. It was confirmed the presence of 36 species,29 genera in 8 families. Twenty-five species in Cyprinidae was accounted for 69.4% of the total, four species in Cobitidae 11.1% of the total species number. The dominant species in the Gap stream water system was Zacco platypus (relative abundant 52.0%), the subdominant species was Carassius auratus (9.2%). The major dominant species in the each tributary of the Gap stream water system were Zacco platypus (Daejeon stream, 87.0%; Yoodeung stream, 41.5%; Gap stream, 47.5%). Number of Korean endemic species was 12 species in the Gap stream water system and that was a 24.5% of the total Korean endemic species. Ten rare species accounted for less than 0.3% of the total individual numbers. The mean species dominance, diversity and evenness indices of the fish community from the Daejeon stream were 0.76, 0.25 and 0.28, respectively: from the Yoodeong stream, 0.20, 0.65 and 0.83, respectively; from the Gap stream, 0.25, 0.83 and 0.77, respectively. The fish community of the Yoodeung stream was showed closer relationship to that of the Gap stream than to that of the Daejeon stream.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.27 no.1
• /
• pp.13-20
• /
• 1991

This paper describes the fish-density dependence of the mean backscattering strength with aggregations of encaged, free-swimming fish of known density in relation to the experimental verification of echo-integration technique for estimating the density of fish shoals. In this experiment, various numbers of gold crussian, Carassius burgeri burgeri, with a mean length of 18.5cm and a mean weight of 205.9g, were introduced into a net cage of approximately 0.76m super(3). During the backscattering measurements. the cage was suspended on the sound axis of the 50kHz transducer having a beam width of 33 degrees at -3dB downpoints. The volume backscattering strengths from fish aggregations were measured as a function of fish density. Data acquisition, processing and analysis were performed by means of the microcomputer-based sonar-echo processor including a FFT analyzer. The calibration of echo-sounder system was carried out at field with a steel ball bearing of 38mm in diameter having the target strength of -40.8dB. The dorsal-aspect target strengths on anesthetized specimens of gold crussian used in the cage experiment were measured and compared with the target strength predicted by the fish density-echo energy relationship for aggregations of free-swimming gold crussian in the cage. The results obtained can be summarized as follows: 1. The target strengths in the dorsal aspect on anesthetized specimens of gold crussian, with the mean length of 19.1cm and the mean weight of 210.5g, varied from -40.9dB to -44.8dB with a mean of -42.6dB. This mean target strength did not differ significantly from that predicted by the regression of echo energy on fish density of free-swimming gold crussian in the cage. It suggests that the target-strength measurements on anesthetized fish was valid and can be representative for live, free-swimming fish. 2. The relationship between mean backscattering strength(, dB) and distribution density of gold $crussian(\rho, $ fish/m super(3)) was expressed by the following equation; =-41.9+11 $Log(\rho)$ with a correlation coefficient of 0.97. This result support the existence of a linear relationship between fish density and echo energy, but suggest that this line has steeper slope than the regression by the theory of estimating the density of fish schools.

• Journal of Aquaculture
• /
• v.8 no.3
• /
• pp.171-181
• /
• 1995

Gonadosomatic index (GSI) of the crucian carp (Carassius auratus) was investigated to clarify annual reproductive cycle from February in 1992 to October in 1994. The values of GSI were high with individual variation from April to July which period was coincided with the breeding season of fish. The GSI was very low in August and September, when follicular atresia developed in the ovaries. GSI value began to increase in October and reached a peak around the following March, which indicated that ovarian follicles may grow during this period. Human chorionic gonadotropin (HCG 10 IU), $17\alpha$, 20\beta-dihydroxyprogesterone\;(1-100{\mu}g/ml)$ and phorbol 12-myristate-13-acetate (TPA, protein kinase C activator, 0.1-10${\mu}M$) induced germinal vesicle breakdown (GVBD), but $4\alpha-phorbol$ 12, 13- didicanoate ($4\alpha-PDD,\;phorbol\; ester\;analogue,\;25{\mu}M$) did not induce germinal vesicle breakdown in the follicular oocytes. Prostaglandin $F_{2\alpha}$ $(0.1-10 {\mu}g/ml)$ and TPA $(0.1-10 {\mu}M$ induced ovulation of the oocytes, but $4\alpha-PDD$ $(25{\mu}M)$ did not induce ovulation of the follicles. $17\alpha-hydroxyprogesterone$ production was examined from the isolated follicles to investigate the steroid production ability in the crucian carp ovaries. HCG (1 lU, 10 lU) and forskolin (adenylate cyclase activator, 0.1-10 ${\mu}M$) stimulated $17\alpha-hydroxyprogesterone$ production. The time course of HCG (10 lU) and forskolin $(10\;{\mu}M)$ stimulated $17\alpha-hydroxyprogesterone$ production within 3 hours, the elevated levels were maintained during the rest of the culture period. The data indicates that cyclic AMP and protein kinase C may play important roles in the oocyte maturation and ovulation in crucian carp.

• Journal of fish pathology
• /
• v.30 no.2
• /
• pp.89-96
• /
• 2017

The majority of freshwater ornamental fish are imported and distributed domestically, causing high risk of exposure to exotic pathogens and drug resistant bacteria in Korea. Aeromonas hydrophila is known as a common species of fresh water bacteria and opportunistic fish pathogen, as well as a species causing zoonotic infection. In this study, we isolated motile aeromonads from various imported freshwater ornamental fish and studied the characters of the isolates. Imported freshwater ornamental fish were purchased on day 1 after the fish were deposited in the aquarium. Bacteria were isolated from the liver, kidney and spleen of fish using 0.5% NaCl containing tryptic soy agar medium. Bacteria were grouped on the basis of their morphological characteristics. The colonies with clear zone on starch-ampicillin agar (SA agar) were tentatively identified as Aeromonas spp. Two hundred and twenty-six strains, about 70% of total isolates were assumed to be Aeromonas spp. Nine isolates were further identified based on the result of the API 20E test and PCR using primers specific for A. hydrophila 16S rRNA gene. The isolates were identified as A. hydrophila and the API 20E test showed differences in trisodium citrate, D-sucrose, D-melibiose, amygdalin and L-arabinose availability between the nine isolates and standard A. hydrophila. The susceptibilities of the isolated bacteria to 10 antibacterial agents were confirmed by the disk diffusion method. Isolated strains were found to be resistant to amoxicillin and ampicillin and sensitive to florfenicol. However, 7 isolates showed multiple drug resistances to erythromycin, oxytetracycline, nalidixic acid etc. Pathogenicity of the isolates was determined by the artificial challenge test on goldfish (Carassius auratus). Three isolates caused 60 ~ 80% mortality in goldfish within 5 days after the initiation of challenge. These results indicate that multiple drug resistant, highly pathogenic and exotic A. hydrophila can spread to domestic aquarium and the preventive treatment of fish before sale is necessary.

• Korean Journal of Ichthyology
• /
• v.23 no.4
• /
• pp.288-299
• /
• 2011

Freshwater fish fauna and community structure were surveyed through 21 lakes in the Yeungnam area including Gyeongsangbukdo and Gyeongsangnamdo provinces, Korean Peninsula from April 2008 to October 2009. Among 21 lakes, 16 lakes belong to the Nakdong River and 5 are independent drainages. From the present study, 61 species (44 genera, 15 families) were collected including 32 cyprinid species (52.5%), 6 cobitid species (9.8%) and so on. The dominant and subdominant species in aspect of the number of individuals were Hypomesus nipponensis (26.6%) and Squalidus gracilis majimae (14.8%), respectively. On the other hand, in aspect of in biomass, dominant and subdominant species were Lepomis macrochirus (19.8%) and Cyprinus carpio (14.7%), respectively. Among 61 examined species, there were found 20 Korean endemic species and 2 Korean endangered species (Pseudobagrus brevicorpus and Pungitius kaibarae). P. brevicorpus was found in Yongyeonji and Yeongcheonho, and P. kaibarae in Yongyeonji. In addition, 5 exotic species were identified such as Cyprinus carpio nudus (leather carp), Carassius cuvieri, Hypophthalmichthys molitrix, Lepomis macrochirus and Micropterus salmoides. Interestingly, a bluegill L. machrochirus appeared dominant or subdominant species in 5 of 21 examined lakes. Five species introduced from the other rivers in Korean Peninsula were additionally described. In the present study, it was first reported that Micropercops swinhonis inhabits in the Nakdong river basin. The fish species diversity, evenness and dominant indices were examined, and a dendrogram based on similarity indices of inhabiting species among the 21 examined lakes was constructed and discussed.