• Journal of fish pathology
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• v.18 no.3
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• pp.259-268
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• 2005

This study was conducted to know the differences in pathology between artificially induced hemorrhagic anemia (EHA) and hemolytic anemia (ELA) during the anemic and recovery course, using Nile tilapia (Oreochromis niloticus). EHA were induced by repeated bleedings with a volume of about 1% of body weight through caudal vein. ELA were induced by intraperitoneal injections of 1% phenylhydrazine for 2 times. A period of 16 to 49th day was arbitrarily taken as a recovery phase. There were no prominent clinical signs and gross findings except for pale gills during the anemic state of both. Characteristic erythrocytes with a weekly stained cytoplasm started appearing on the 12th day in both and were still noted on the 49 and 20th day respectively in EHA and ELA. EHA and ELA were normocytic hypochromic and macrocytic normochromic in type respectively, although both were normocytic hypochromic during the recovery phase. In liver, fatty degeneration around central vein on the 12-38th day in EHA and hyaline degeneration around central vein on the 12-26th day in ELA were found. In head kidney, increased hemopoiesis was observed on the 12-26th day in EHA and on the 2-12th day in ELA, and macrophages engulfing erythrocytes were observed on the 16-38th day in EHA and on the 2-12th days in ELA. In spleen, activated ellipsoids on the 12-26th day in EHA. and on the 2-20th day in ELA. In ELA, severe accumulation of hemosiderin in both spleen and head kidney were constantly noted from the 2-49th day. On the 49th, Ht was recovered but Hb was still lower than that of control in both anemia.

• Journal of fish pathology
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• v.11 no.1
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• pp.51-60
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• 1998

Concerned to the lyfe cycle of Ichthyophthirius multifiliis, the experimental infection and development of the parasites were studied in the several freshwater cultured fishes. Opitimum conditions for the propagation of the parasite by serial passage with the rainbow trout fry was observed. Visiable white spots were examined in the body surface, fins and gills of the healthy fries, and a stable infection has been maintained for 2 months in the experimental system (Temperature: $18{\pm}1^{\circ}C$ DO: 7-7.5 ppm; pH: $7{\pm}0.2$). Induction conditions for artificial infection of the parasite by interms of the host fishes, stages of the parasites, and rearing temperature regimes was investigated. Rainbow trout fries showed a positive infection which was resulted from exposure of theront at $18^{\circ}C$. The rainbow trout fries induced white spots on the body surface at 3-7 days exposure to the theronts at $18^{\circ}C$. It was found that exposure of the rainbow trout fries exposed to 1,000 theronts per fish (10 theront/ml) for 45-60 minutes at $18^{\circ}C$ would consistently produce infection. Perfect infection (100%) was induced when the fries were exposed to 1,500 theront per fish (15 theront/ml) under laboratory condition. Development of I. multifiliis in the rainbow trout was observed for 7 days postexposure (PE). The parasite increased in average diameter from $54{\mu}m$ on the 1st day PE to $426{\mu}m$ on the 7th day PE. In the initial infestation period, the parasites were found on the gill epithelium, and on the 3rd day PE they invaded into the basal part of the gill filament adjacent to the major blood vessels, particularly the afferent vessels. Morphological change of buccal apparatus were observed on the 2nd day PE. Contractile vacuoles were more prominent on the 4th day PE, and they had notable changes on the 7th day PE.

• Korean Journal of Ecology and Environment
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• v.45 no.2
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• pp.218-231
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• 2012

The objectives of this study were to evaluate the physico-chemical water quality, trophic and tolerance guilds in the control ($C_o$) and impacted streams of the abandoned mine, along with the ecological health, using a multimetric health model and physical habitat conditions of Qualitative Habitat Evaluation Index (QHEI), during the period of three years, 2005~2007. Also, eco-toxicity ($EE_t$) enclosure tests were conducted to examine the toxic effects on the outflows from the mine wastewater, using the sentinel species of Rhynchocypris oxycephalus, and we compared the biological responses of the control ($C_o$) and treatment (T) to the effluents through a Necropybased Health Assessment Index ($N_b$-HAI). Tissue impact analysis of the spleen, kidney, gill, liver, eyes, and fins were conducted in the controlled enclosure experiments (10 individuals). According to the comparisons of the control ($C_o$) vs. the treatment (T) in physicochemical water quality, outflows from the abandoned mine resulted in low pH of 3.2, strong acid wastewater, high ionic concentrations, based on an electrical conductivity, and high total dissolved solid (TDS). Physical habitat assessments, based on Qualitative Habitat Evaluation Index (QHEI) did not show any statistical differences (p>0.05) in the sampling sites, whereas, the $M_m$-EH model values in a multimetric ecological health ($M_m$-EH) model of the Index of Biological Integrity (IBI), using fish assemblages, were 16~20 (fair condition) in the control and all zero (0, poor condition) in the impacted sites of mine wastewater. In addition, in enclosure eco-toxicity ($EE_t$) tests, the model values of $N_b$-HAI ranged between 0 and 3 in the controls during the three years, indicating an excellent~good condition (Ex~G), and were >100 (range: 100~137) in the impacted sites, which indicates a poor condition (P). Under the circumstances, organ tissues, such as the liver, kidney, and gills were largely impaired, so that efficient water quality managements are required in the outflow area of the abandoned mine watershed.

• Korean Journal of Food Science and Technology
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• v.18 no.1
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• pp.42-47
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• 1986

The fatty acid composition of lipids extracted from 18 kinds of salted and fermented sea foods which have been consumed in Korea were examined. The lipid contents of salted and fermented sea foods showed wide difference (0.8-11.9%) depending on species and portions of raw materials. In fatty acid composition of salted and fermented sea foods prepared with whole fishes, the saturated fatty acid was the most predominant component, and the major fatty acids were 16:0, 18:1, 22:6, 16:1 and 20:5. In case of salted and fermented products prepared with gills, roe or intestines, the polyenoic fatty acid was the main component, the major fatty acids were 18:1, 16:0, 22:6, 20:5, 16:1 and 18:3. In these products the composition ratios of 20:5 and 18:3 were higher, and that of 16:0 and 16:1 were slightly lower as compared with salted and fermented whole fish products. And in case of salted and fermented crustacea and mollusk, the polyenoic fatty acids such a 22:6 and 20:5 were the most predominant component, the abundant fatty acids were 22:6, 16:0, 20:5, 18:1 and 16:1. Judging from results, salted and fermented sea foods were abundant of the highly unsaturated fatty acids such as 20:5, 22:6 inspite of the long fermentation periods.

• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.229-246
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• 2023

The bitterling (Cyprinidae, Acheilongnathinae) is a temperate freshwater fish with a unique spawning symbiosis with host mussels. Female bitterlings use their extended ovipositors to lay eggs on the gills of mussels through the mussel's exhalant siphon. In the present study, in April of 2020, we investigated spawning frequencies and patterns of three bitterling fish species in host mussel species in the Nakdong River basin (Hoecheon). During field surveys, a total of four bitterling and three mussel species were found. We observed bitterling's spawning eggs/larvae in the three mussel species: Anodonta arcaeformis(proportion spawned: 45.5%), Corbicula fluminea(12.1%), and Nodularia douglasiae (45.2%). The number of bitterlings' eggs/larvae per mussel ranged from 1 to 58. Using our developed genetic markers, we identified the eggs/larvae of each bitterling species in each mussel species (except for A. macropterus): A. arcaeformis (spawned by Acheilognathus yamatsutae), C. fluminea (A. yamatsutae and Tanakia latimarginata), and N. douglasiae (A. yamatsutae, Rhodeus uyekii, and T. latimarginata). Approximately 57.6% of N. douglasiae mussel individuals had eggs/larvae of more than one bitterling species, suggesting that interspecific competition for occupying spawning grounds is intense. This is the first report on bitterling's spawning events in the Asian clam C. fluminea from Korea; however, it should be ascertained whether bitterling's embryo undergoes successful development inside the small mussel and leaves as a free-swimming juvenile. In addition, the importance of its conservation as a new host mussel species for bitterling fishes needs to be studied further.

• Journal of fish pathology
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• v.1 no.1
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• pp.5-30
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• 1988

This is a comprehensive study for considering the effective treatment and control program of bacterial disease occurring in common carp, israel carp, color carp, crucian carp, eel and tilapia by clarifying the causes, mechanism of infection and onset and the diagnostic criteria. As a first step, the authors investigated the external views, gross and histopathologic findings of diseased fish using 450 infected fishes obtained from various farmer of Korea. This infection was characterized by hyperemia, hemorrhage and swelling of body surface and fins, congestion of liver, spleen, kidney, inflammation of intestine, hemorrhagic inflammation of various tissues, and necrosis and ulcer of various tissues were accompanied in serious cases. Bacteriologically, Aeromonas hydrophila and Edwardsiella tarda were isoiated from these fishes. Particularly in the regular check on 222 eels, 177 strains were isolated as 29.94% of Aeromonas hydrophila, 48.58% of Edwardsiella tarda and 21.47% of Flexibacter columnaris. Hexibacter columnaris was isolated from corroded gill of eels. The identical disease was occurred by innoculating the isolated Aeromonas hydrophila and Edwardsiella tarda and the identical strains were isolated from infected experimental fishes. The eels which were diagnosed Aeromonas disease from Kwangju, Pusan accompanied hemorrhage, swelling of body surface and fins, inflammation of stomach and intestine containing mucous fluids mixed with the pathogens. Color carp and crucian carp which were innoculated with the isolated 5 strins of Aeromomas hydrorphil died within 3 or 4 days accompanying with the characteristics of Aeromonas disease. Edward disease was characterized by abscesses of body surface, pus formation with concentration on phagocytes. The size of absecsses increased with progression elf disease. There were also various abscesses at internal organ and white nodules appeared in kidney. Histologically, various progressive granuloma were examined without inflammation of intestine. Columnaris disease of eels showed no hemorrhage except slight white body color. In autopsy, most of internal organs appeared normal and there were no septic odors. The only character was corrosion of gills. In order to treat these bacterial diseases, infected fishes must bathe in 20ppm chloramphenicol or kanamycin solution for 1 hour. Besides, medication program in oral ingestion of 75mg/kg chloramphenicol per day continuing for 5 to 7 days. After injecting the formalin treated Aermonas hydrophila antigen into carp, relatively high agglutination titer showed between 3 weeks and 6 weeks. Though this titer decreased from that time, it was continued for 18 weeks. In the case of injecting the formalin treated Edwardsiella tarda antigen into tilapia, the titer also increased. But tilapia which were immersed in the suspension fluid of the formalin treated Edwardsiella tarda showed no increase of the titer.