• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.2
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• pp.66-71
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• 2006

Fluoroquinoles have a wide range of antimicrobial properties and are effective in the treatment of bacterial diseases in fish. The use of fluoroquinoles continues to grow steadily. Fluoroquinolone antibiotics are probably the most important class used among synthetic antibiotics in human and veterinary medicines because of their broad activity spectrum and good oral absorption. This study was conducted to estimate the residue of antibiotics in four species of farmed fishes, including olive flounder (Paralichthys olivaceus), black rock fish (Sebastes schlegeli), red sea bream (Pagrus major), and sea bass (Lateolabrax japonicus), collected from fish farms located in the southern coastal area of Korea. The residues of fluoroquinolones were determined using high performance liquid chromatography (HPLC) with a fluorescence detector. Residuals of five fluoroquinolones in muscle tissue of farmed fish were analyzed. We found that enrofloxacin was the most common agent in fish muscle, and that ciprofloxacin was the next most common. The range of detected concentrations of fluoroquinolones in olive flounder muscle was 0-0.859 mg/kg in 32.6% of all samples. Enrofloxacin was commonly detected in sea bass muscle at a range of 0-0.143 mg/kg in 38.9% of all samples. Fluoroquinolones were detected in 6.9% of black rock fish muscle and in 16.6% of sea bream, although the detected concentration was below 0.01 mg/kg. The maximum detection value of enrofloxacin and ofloxacin in olive flounder at the time of shipping was 0.102 mg/kg and 0.09 mg/kg, respectively; no other antimicrobials were detected. We detected no antimicrobial substances in red sea bream.

• The Korean Journal of Zoology
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• v.16 no.2
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• pp.79-96
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• 1973

In order to elucidate the effects of copper on Corassius carassius, the following were studied: 1) lactate dehydrogenase isozyme patterns by cellulose acetate electrophoresis, 2) LDH activity and copper effect on LDH enzyme system y spectrophotometry, 3) esterase isozyme patterns by agar thin layer electrophoresis, 4) hemoglobin patterns by starch gel electrophoresis, and 5) histological study. 1. There were two bands of LDH isozymes (LDH-3 and LDH-5) in the gill, three bands (LDH-2, LDH-4, and LDH-5) in the liver, and two bands (LDH-3 and LDH-4) in the muscle of the normal fish. The LDH-1 bond was not found in the above three tissues. When the fish were exposed to copper, LDH-3 appeared in the liver, LDH-5 in the muscle, but no new LDH band appeared in the gill. 2. The sepcific activities of the LDH were lowest in the gill and highest in the muscle of the normal fish, and they were gradually decreassed in the gill and highest in the muscle of the normal fish, and they were gradually decreased in the liver and mucle except in the gill from 1-day to 10-day exposure to copper. It indicates that LDH activities in the liver and muscle of the fish were inhibited by copper. 3. Through in vitro experiment, it is clear that the decrease of the LDH activities of the liver and muscle of the fish exposed to copper is mainly caused by the inhibition on the M-LDH in the fish. 4. The numbers of the esterase isozyme bands of the gill, liver, muscle, blood, brain, and kidney of the normal fish were 3, 6, 2, 2, 2, and 2 respectively, and these numbers were the same as those exposed to copper. The relative mobilities of the esterase bands in the gill, liver, blood, and kidney of the exposed group were different from those of the control. 5. There was one hemoglobin band on the anode in the normal fish. It seems that the nobility of hemoglobin band of the fish exposed to copper was slightly faster than that of the normal fish. 6. The normal gill lamellae of the fish consisted of centrally located pillar cells and a number of mucus cells. When the fish were exposed to copper, the epithelial layer was divorced first, disintegrated, and then destroyed completely. 7. The liver of the normal fish had prominent central veins, cords of hepatic cells, and sinusoids. When the fish were exposed to copper, numerous droplets of fat appeared in the cells around the central vein of the liver. It is assumed that the fatty droplets were accumulated by the lesion due to fatty metamorphosis of the liver caused by copper. 8. There was no histological difference between the muscle of the normal fish and that of the fish exposed to copper. 9. In the normal fish, the tubules of the kidney were surrounded by hemopoetic tissues. However, the kidney tissue of the fish exposed to copper received some damage on the proximal tubules. Since the tubule cells were reduced in height, the lumens of the tubules were enlarged. Consequently many proximal tubules exhibited some pink-stained granular casts and various stages of degeneration.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.3
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• pp.296-308
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• 1996

Proteolytic enzymes responsible for post-mortem degradation of the fish tissues have been studied in regard with screening the proteases distributed in the fish body by reacting with the specific synthesized substrates. Activities of cathepsin L, B, H, G, and D like enzymes were detected in the muscle crude protease from the both kind of fish, dark fleshed fish (anchovy, Engraulis japonica, and gizzard-shad, Clupanodo punctatus) and white fleshed fish (seabass, Lateolabrax japonicus, and sole, Pleuronichthys cornutus), however, those of chymotrypsin, trypsin, pepsin, and peptidase like enzymes were observed 3n the viscera crude pretense from the fish. Proteolytic activities of the muscle crude protease at pH 6.0 were similar to those of the viscera crude protease at pH 8.0, but, those of the viscera crude protease at pH 8.0 were about 2 times higher than those at pH 6.0. The muscle and viscera crude protease from anchovy showed the strongest proteolytic activity among the four fish crude proteases and the proteolytic activity of the viscera crude protease was approximately 100 times higher than that of the muscle crude protease, which suggest that viscera proteases were more contributed on the development of post-mortem changes than muscle proteases. With the degradation patterns on SDS-polyacrylamide gel electrophoresis against yellowtail myofibrillar proteins, the muscle and viscera crude protease of the four fishes were primary responsible for the degradation of myosin heavy chain, and myosin light chain and actin, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.6
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• pp.869-879
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• 2012

This study was conducted to investigate the effects of dietary lipid source and level on growth performance, blood parameters, fatty acid composition and flesh quality of sub-adult olive flounder Paralichthys olivaceus. Eight experimental diets were formulated to contain 5% squid liver oil (SLO), 5% linseed oil (LO), 5% soybean oil (SO), a mixture of 1% squid liver oil, 2% linseed oil and 2% soybean oil (MIX), no lipid supplementation with high protein level (LL-HP), 10% squid liver oil (HL-SLO), a mixture of 1% squid liver oil, 4.5% linseed oil and 4.5% soybean oil (HL-VO), and 1% squid liver oil with high starch level (LL-HC), respectively. Two replicate groups of fish (average initial weight of 296 g) were fed the diets for 17 wks. After 5 wks, 11 wks and the end of the feeding trial, five fish from each tank were randomly sampled for analysis of body composition. At the end of the feeding trial, final mean weight of fish fed the LL-HP diet was significantly (p<0.05) higher than that of fish fed the HL-VO diet, but did not differ significantly from those of fish fed the SLO, LO, SO, MIX, HL-SLO and LL-HC diets. Fish fed the LL-HP diet showed significantly higher feed efficiency than fish fed the LO, HL-SLO and HL-VO diets. Feed efficiency of fish fed the LO, SO and MIX diets were similar to those of fish fed the SLO and HL-SLO diets. Fish fed the HL-SLO diet showed significantly higher total cholesterol content in plasma compared with other diets. Fatty acid composition of tissues was reflected by dietary fatty acid composition. The highest linoleic (LA) and linolenic acid (LNA) contents in the dorsal muscle were observed in fish fed the SO and LO diets, respectively, regardless of feeding period. The highest eicosapentaenoic acid (EPA) content in the dorsal muscle was observed in fish fed the LL-HP and LL-HC diets after 11 and 17 weeks of feeding, respectively. Fish fed the SLO and HL-SLO diets showed higher docosahexaenoic acid (DHA) content than that of other treatments after 11 and 17 weeks of feeding, respectively. Dietary inclusion of vegetable oils reduced n-3 HUFA contents in the dorsal muscle and liver of fish. The n-3 HUFA contents in tissues of fish fed the SLO and HL-SLO diets were higher than those of fish fed other diets, except for the LL-HP and LL-HC diets. Hardness, gel strength, chewiness and cohesiveness values of dorsal muscle in fish were significantly affected by dietary lipid source. The results of this study indicate that fish oil in fish meal based diets for sub-adult olive flounder could be replaced by soybean oil and linseed oil without negative effects on growth and feed utilization.

• Korean journal of food and cookery science
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• v.16 no.4
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• pp.352-357
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• 2000

This study was conducted to investigate the effect of the lipid and collagen content and drip volume on the hardness of fish meat. Red sea bream (cultured and wild) and flounder (cultured, cultured with obosan and wild) were used for this study. Textural differences between cultured and wild meats were determined by the measurements of hardness, lipid and collagen content, and drip volume. Lipid content of the dorsal muscle was higher especially in cultured red sea bream (3.32%) than in wild one. Cultured and wild flounder contained lower content of lipid than red sea bream. The content of collagen was higher in cultured flounder fed with obosan (8.37 mg/g muscle) and wild flounder (8.02 mg/g muscle) than others. Drip volume was the highest in cultured flounder fed with obosan (8.67%). The hardness of raw meat was correlated with the contents of lipid (r= -0.7063) and collagen (r= 0.8307), significantly. Cultured fish contained more lipid and less collagen than wild one. So, the hardness of these fish meats was lower than wild one. However, cultured flounder fed with obosan showed no difference in hardness compared with wild one. In the cooked meat, there was no relationship between the hardness of fish meat and the contents of lipid and collagen. But, the drip volume was significantly related with the hardness (r= 0.6870). From these results, the factors contributing the textural difference between wild and cultured fish meat would be the lipid and collagen contents, and two ways to improve the texture of cultured fish meat could be suggested. One is to lower the lipid content by feed control, and the other is to raise the collagen content by inducing more fish movement.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.2
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• pp.264-271
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• 2011

The effect of replacement of fish meal (FM) in diets with sand smelt meal (SSM) on fatty acid composition of carp fry, Cyprinus carpio, was examined. Five isonitrogenous and isoenergetic (38% crude protein, $15.75\;kJ\;g^{-1}$) diets replacing 0, 25, 50, 75, and 100% FM protein by SSM protein were formulated. Each diet was randomly allocated to triplicate groups of fish in aquaria, and each aquarium was stocked with 20 fish (initial average weight of $0.300{\pm}0.65\;g\;fish^{-1}$). Fish were fed twice daily to apparent satiation for 13 weeks. Results indicated that final weight, specific growth rate and feed efficiency ratio of fish fed with different SSM replacement diets did not differ significantly (p>0.05) from fish fed the control diet, except for 100% SSM level. No significant differences were noted among experimental treatments on dry matter, protein, lipid and ash contents of the fish body composition (p>0.05). Fatty acid analysis showed that saturated fatty acids in fish muscle significantly decreased, but monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) did not change with increasing dietary SSM. However, some changes also could be observed for some particular fatty acids in experimental fish. For example, the amounts of 15:0, 17:0, 18:1n-7, 18:2n-6 and 22:5n-3 significantly increased, but 16:0, 18:1n-9, 18:3n-3 and 20:1 n-9 significantly decreased with increasing dietary SSM. Total n-6 PUFA increased with increasing dietary SSM, but total n-3 PUFA were not changed in muscle of fish fed the experimental diets. The ratio of n-3 to n-6 was not affected significantly in muscle of fish fed the experimental diets containing different proportions of SSM, including the control diet.

• Korean journal of food and cookery science
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• v.17 no.5
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• pp.517-522
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• 2001

Changes of nucleotides and their related compounds in raw, cooked and frozen fish muscle were studied with HPLC. Red sea bream(cultured and wild) and flounder(cultured, cultured with Obosan(equation omitted) and wild) were used for this study. In nucleotides, contents of ATP was similar to that of IMP and some of H$\times$R(inosine) and H$\times$(hypoxanthine) were existed in fresh muscle. ATP was decomposed rapidly and contents of IMP became different between cultured and wild fish after 6 hours. The content of IMP was lower in the cultured red sea bream(3.39$\mu$ mole/g) and flounder(3.17$\mu$ mole/g) than in the wi1d red sea bream(7.31$\mu$ mole/g) and flounder(5.03$\mu$ mole/g). But, the flounder cultured with Obosan contained the largest amounts of IMP After 24 hours, K values of cultured fish muscle(27.7%, 28.2%) were higher than that of wild ones(22.8%, 24.3%). The K value of cultured flounder fed with 0.3% Obosan(equation omitted)(25.7%) was between cultured and wild flounder. IMP was the one which existed the most in cooked and frozen muscle. Amounts of H$\times$R and H$\times$ were more in cooked and frozen muscle. than in raw muscle. From these results, we could suggest that the wild one was more palatable and fresher than the cultured one and the palatability of cultured one seemed to be improved depanding on the feed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.2
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• pp.120-128
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• 1976

Two experiments were conducted to study the nature of protein degradation in fish muscle postmortem, first one with English sole (Paraphyrus vetulus) followed by another with rockfish (Sebastodes spp.). In the first one, proteolysis was measured by the increase of amino-N in gutted fish during storage in ice and in the homogenates prepared from fish of different ice storage during $20^{\circ}C-incubation$. In order to test the possible involvement of fish muscle a cathepsin, a portion of each homogenate sample was exposed to 0.5 Mrad of gamma radiation to destroy viable microorganisms prior to the incubation. Proteolysis was not detected until viable count reached a level above $10^7$ cells per gm fish flesh, corresponding to 31 days of ice storage. Even if fish flesh were mechanically disrupted by means of homogenization and subsequently incubated at $20^{\circ}C$, proteloysis attributable to muscle cathepsin was not detected. In the second with rockfish muscle aseptically prepared from freshly killed fish, the samples were inoculated with a proteolytic strain of fish spoilage Pseudomonad or irradiated at 0, 0.5 and 3.0 Mrad. The four samle groups were stored at $0-2^{\circ}C$ to compare the spoilage pattern of sterile and non-sterile muscle. In sterile muscle both total-N (extracted in 0.5M KCl) and amino-N $(soluble\;in\;70\%\;ethanol)$ declined slightly while the inoculated muscle showing increase in parallel with the increase of number of inoculated bacterium. The results indicate that proteolysis is a part of normal fish spoilage and the onset of proteolysis is delayed until viable count reaches its maximum level. Contribution of fish muscle cathepsin to protein degradation in white flesh fish muscle post-mortem is nil.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.3
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• pp.175-178
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• 2004

We here report that the muscle of 'gukmeri-bok' puffer fish (Takifugu vermicularis radiatus) is intoxicated after freezing and thawing processes even though it is not toxic when it is fresh. This study was carried out to investigate the effect of different freezing and thawing conditions as well as the effect of the presence of skin or viscera on the intoxication of muscle of 'gukmeri-bok' puffer during freezing and thawing process. As a result of this investigation, thawing condition, but not freezing conditions or periods played an important role in muscle intoxication. Tetrodotoxin secretory grands exist in the skin of toxic puffer fish, the skin was more responsible for the muscles intoxication than the viscera during the freezing-thawing process. In other words, no toxicity was measured in the muscle of skinned-frozen specimens even when thawed. According to this result, it is recommended that the skin and viscera must be removed before being frozen for edible purpose. Otherwise, when a whole fish should be frozen, alternative half-thawing and removal of skin from frozen specimens is recommended.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.6
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• pp.462-468
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• 2004

In order to evaluate adaptation to the environment in released fish, digestive organ and body composition were compared among 1-year old cultured (CUL), released (REL) and wild (WIL) Black Sea Bream, Acanthopagrus schlegeli. Hepatosomatic index (HSI) of the REL was significantly lower than those of the CUL and WIL fish, but intestine weight index (IWI) of REL was significantly higher than those of the CUL and WIL fish. There were no significant differences in stomach weight index (SWI) and condition facto. (CF) among those different fish groups. The number of pyloric caeca of the REL and WIL fish were 4, but the $30{\%}$ of CUL fish was 3 counts. The moisture content of whole body in the WIL fish was significantly higher than the CUL and REL fish, but significant lowest in the crude lipid of whole body. The content of moisture and crude protein of dorsal muscle were no significant differences among the CUL, REL and WIL fish, but crude lipid content of WIL fish was significantly lower than the CUL and REL fish. Moisture content of CUL fish in the liver was significantly lower than the REL and WIL fish, and crude lipid was significant lowest in the WIL fish. Amino acid content of dorsal muscle in the WIL fish was highest in the total amino acid, EAA and E/A ratio, and CUL fish was highest EAA and E/A ratio in liver. EPA content in dorsal muscle of WIL fish was lower than CUL and REL fish, and the REL fish was highest in DHA content of the fatty acid. EPA content in liver of WIL fish was lower than CUL and REL fish, and DHA content in REL and WIL fish was highest and lowest. Crude protein content of CUL and WIL fish in the scale was significantly higher than REL fish, but there were no significant differences in contents of crude lipid and ash. Ca and P of scale were formed most of mineral and content of P in CUL fish was significantly higher than those of REL and WIL fish. There were no significant differences in Mg, K, Na and S of scale, but CUL fish was significantly lower than REL fish in C1. The results suggest that difference of digestive organs and body composition concluded it from differences of inhabitation environment and feed formulations.