• Progress in Medical Physics
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• v.17 no.4
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• pp.252-259
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• 2006

Gap junctions are distributed within various cells and function as electrical synapses by freely exchanging small molecules. In the retina, the practical role of gap junctions in an animal's motion detection has not been investigated very much. In this study, optometer response (OMR) was used to Investigate the effects of drugs which modulate electrical synapses between retinal ceils. An Injection of carbenoxolone, 8-Br-cAMP, sodium nitroprusside (SNP) or 8-Br-cGMP decreased goldfish's OMR in both light and dark conditions. In light conditions, an intravitreal injection of dopamine, SKF-38393 or eticlopride decreased OMR and that of SCH-23390 increased it. In dark conditions, the injections produced opposite results: dopamine, SKF-38393 and eticlopride increased OMR and SCH-23390 caused OMR to decrease. These results indicate that gap junctions between retinal cells have an Important role in goldfish's motion detection.

• Journal of Life Science
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• v.26 no.11
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• pp.1308-1312
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• 2016

Heavy metals such as gallium (Ga) cause serious physiological damage to exposed organisms, mostly of aquatic species. Ga one of the inter-metallic, transition elements increasingly being used in making high-speed semiconductors, such as Ga arsenide. The purposes of this study were to investigate the effects of Ga on acute toxicity, serum biochemical changes, and erythrocyte morphological changes in the blood stream of goldfish (Carassius auratus). Median lethal concentrations were determined in acute tests. The 96 hr $LC_{50}$ value was 9.15 mg/ml. Goldfish were exposed to different Ga concentrations (2.0, 4.0, and 8.0 mg/ml) for 30 days to assess its toxic effects. The results indicate that the measured serum biochemistry parameters (including glucose, blood urea nitrogen, creatinine, cholesterol, and triglyceride) of the Ga-exposed fish groups differed significantly from the untreated fish group. In addition, a change in the erythrocytes' morphology at a high concentration (8.0 mg/ml) of Ga exposure shows respiratory problems. Our results suggest that 2.0 mg/ml is proposed as a biologically safe concentration that can be used for establishing tentative water quality criteria concerning the same-size goldfish.

• Journal of fish pathology
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• v.9 no.1
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• pp.1-9
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• 1996

Many encysted metacercariae of Clinostomum complanatum(Rudolphi, 1814) were found in the flesh near the skin of goldfish(Carassius auratus) sultured at a fish farm in Chonbuk Province, Korea, in the summer of 1995. The mortality reached about 7% from July 10 to August 20. Encysted and excysted metacercariae were$700\sim877{\times}700\sim775{\mu}m$ and $2.4\sim5.5{\times}0.7\sim1.37{\mu}m$ in size, respectively. The parasites looked yellowish due to the yellow particulate matter in the intestine. Of 276 fish examined, 234(84.8%) were infected with a mean intensity of 216.6(range 1~1.214) parasites. Fish of 2.0~2.5 cm in body length were most frequently(94.3%) infected but those of 3.1~3.5 cm were the least infected(75.27%). The isthmus was most heavily infected. There was no difference in prevalence between two forms of goldfish, Gyariko an Ryugum. The sites of infection were swollen and recognized as yellow spots of 0.4~0.8 mm in diameter. Fish infected with more than 200 metacercariae became moribund with listless swimming and finally died.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.10a
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• pp.68-69
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• 2000

어류의 심전도에 대한 연구는 Oets (1950)가 뱀장어 (Anguilla vulgaris)의 체표면에 전극을 부착하여 심전도를 기록한 것을 시작으로, Otis (1957)가 금붕어(Carassius auratus)의 체내에 전극을 삽입하여 수중에서 어류의 심전도를 조사한 후부터 여러 자극에 대한 연구가 활발히 진행되고 있다. (중략)

• Proceedings of the Korean Society of Life Science Conference
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• 2003.10a
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• pp.116-116
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• 2003

• Korean Journal of Environmental Agriculture
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• v.3 no.2
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• pp.43-49
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• 1984

The acute toxicity of an insecticide cartap to several species of freshwater animals was evaluated in the laboratory with special reference to the species specificity, effects of water temperatures and pH values. The aquatic animals tested were the Carassius auratus L., Aphyocypris chinensis $G{\"{U}}NTHER$, Misgurus anguillicaudatus CANTOR, Moina macrocopa STRAUS. The susceptibility of aquatic animals to cartap was different with the species of animals. At the water temperature of $25^{\circ}C$ and pH 7, TLm values of the insecticide to the C. auratus L., A. chinensis G. and M. anguillicaudatus were 0.88, 0.26 and 0.13 ppm in 48 hours, respectively, and to Moina macrocopa S., 306 ppm in 3 hrs. In the case of the three species of fish, TLm 48 values were significantly decreased with rise in temperature. In the case of water flea, where TLm value was 107 ppm at $20^{\circ}C$, there was no consistent response to temperature change, with the highest figure at $25^{\circ}C$ than at either 20 or $30^{\circ}C$. and the susceptibility of C.auratus L. and A. chinensis G. greatly decreased with the increase of pH in water. The toxicity to M. anguillicaudatus and M. macrocopa was significantly higher at pH 9 than at pH 6 or 7. In conclusion, the toxicological reactions of the freshwater animals to cartap were variably influenced by the water temperatures and pH values of water and species of animals.

• Applied Microscopy
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• v.27 no.1
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• pp.71-86
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• 1997

The regeneration and differentiation of the cutaneous pigment system in the goldfish, Carassius auratus during the wound healing process were studied with high magnification electron microscope. The cutaneous pigment cells of the normal tissues were composed of three kinds of dermal chromatophores-xanthophores, leucoiphores and melanophores. While xanthophores contain two kinds of pigment granules-pterinosomes and carotenoid vesicles, leucophores and melanophores contain amorphous pigment granules (leucosomes) and oval shaped electron dense melanin pigment granules (melanosomes) respectively. After injury, primary wound healing responses being carried out by migration of epidermal cells and hemocytes spreading over the wound surface at the day of wounding. And at the time of primary wound closure, 5 to 7 days after wounding, rER rich cells-presumably common precursors of dermal chromatophores-immigrated into the wound area. First redifferentiated chromatophores appeared 3 weeks after wounding. Pigment granules of the chromatophores were emerged from the cytoplasmic Golgi complex via rough endoplasmic reticulum. Pinocytotic vesicles which associated with accumulation of pigment material, appeared only at the inner surface of the chromatophores adhering to the rER rich cells, characteristically. The differentiation of each chromatophore in addition to integumental wound repair were accomplished within 4 weeks after wounding at most cases, however the total numbers and densities of these repaired chromatophores still primitive state. Moreover, It has been revealed that complete repair of chromatophores at wounded tissues from burns requirs more than 3 months in normal environment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.6 no.3_4
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• pp.112-122
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• 1973

Philometroides carassii (ISHII, 1931) is a parasitic nematode of Carassius auratus and gold fish. Recently a large number of parasitized fishes by this nematode have been reported by fish farmers in Korea. The present investigation was aimed to find out the life cycles of the parasites and effects of chemotherapeutic medicines on the emerged larvae from the adult parasites. Results of the study are summarized as follows : 1. Intermediate host of p. cararsii is a freshwater copepod, Cyclops sp. and the invaded lavae in the body cavity of copepod are capable for parasitizing the fish host after 3 hours of invasion. 2. The lavae eaten directly by the fish host are digested or excreted. 3. The larvae invaded in the fish intestine through the intermediate host pass into the body cavity in 1 to 10 days, and become subadult stage. After 18 to 20 months the subadults parasitic in the body cavity of the Carassius auratus, penetrate through muscle fissile into tile caudal fin where they become adults. Whereas those parasitic in the body cavity of the gold fish, 7 to 8 months the sutadults penetrate through muscle tissue into the caudal fin where they become adults. 1. Male subadults found in the body cavity of the Carassius auratus and gold fish, were larger than females, This is the first record of male subadults occurring in the fish host. 5. Among four different :drugs tested, most of all larvae died in 4 ppm of dipterex in 5 days. But no adults were harmed even in 6 ppm dipterex in 11 days.

• Journal of Life Science
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• v.8 no.3
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• pp.249-256
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• 1998

The purpose of this study was to understand the evolutionary relationships between fish and other vertebrates which had DNA with the genetic defects in homoglobin expression, with comparison to the nucleotide homologies of the ${\beta}$-globin genes. The predicted amino acid sequence from carp ${\beta}$-globin gene was compared with those of other vertebrates from the published data. The nucleotide homologies of the predicted amino acid sequence from the carp ${\beta}$-globin gene with those of goldfish and mirror carp were high, and the rates were 97.3% and 93.9%, respectively. On the other hand, with the previously reported ${\beta}$-globins of goat, frog, human, rat, goose, chicken, and duck, it showed low homology ranging from 45.9 to 58.1%. The carp ${\beta}$-globin has one inserted amino acid residue, which was also found in other fish ${\beta}$globin, but not in other vertebrate ${\beta}$-globins.

• Korean Journal of Ichthyology
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• v.19 no.2
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• pp.93-100
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• 2007

The effects of sudden changes of water temperature (WT) on the physiological response and hematological characteristics of the goldfish (Carassius auratus) were examined by manipulating WT in a flow through freshwater culture system with tanks. The WT was dropped from $15^{\circ}C$ to $10^{\circ}C$ within 1 hour and then returned to the original water temperature within 12 hours and maintained for 12 hours at the normal WT. The WT stress give continued for 3 days. Plasma levels of cortisol, glucose and lactic acid were higher in stress group than that of non-stressed group until 72 hours. However, The $Na^+,\;Cl^-$, osmolality and aspartate aminotransferase (AST) levels showed no significant differences in two groups. This results in stress group showed that goldfish exhibit "typical" physiological responses (in cortisol, glucose, lactic acid, hematocrit, red blood cell and hemoglobin) to the stress induced by WT changes.